Going to take the plunge and get a high efficency gas boiler

Barack Obama

I’ve spent some time and read through a lot of posts on here. There are a lot of really helpful posts from professionals – thanks lads. We have a 5 bed detached house that’s about 15 years old and the building spec is not great. I’ve been insulating the house as much as I can and the next step is to upgrade the boiler. I’d be grateful if someone could help me with a few questions –

It looks like I can get the high efficiency boiler only fitted for about €2k but the boiler and controls fitted to SEAI spec will cost about €3k (including grant). This is a lot extra – is it really worth it?


In order for me to get an SEAI grant for the boiler\controls, it looks like I also have to get a BER certification done as well (at extra cost). Is this correct or will the quote that the seai approved contractor gives me include this as well? It’s not exactly clear on their website…

Cheers

Barack Obama

Forgot to mention that I don;t think a combi-boiler would suit. The reason is that some of the bathrooms are a long way from the boiler and it would take a long time for the hot water to get to the tap - that's the way it is at the minute from the immersion tank anyway.

I'm open to suggestions - we have a pump electric shower only so this relies on hot water in the system.

PMC999

Barack Obama wrote: »

I’ve spent some time and read through a lot of posts on here. There are a lot of really helpful posts from professionals – thanks lads. We have a 5 bed detached house that’s about 15 years old and the building spec is not great. I’ve been insulating the house as much as I can and the next step is to upgrade the boiler. I’d be grateful if someone could help me with a few questions –

It looks like I can get the high efficiency boiler only fitted for about €2k but the boiler and controls fitted to SEAI spec will cost about €3k (including grant). This is a lot extra – is it really worth it?


In order for me to get an SEAI grant for the boiler\controls, it looks like I also have to get a BER certification done as well (at extra cost). Is this correct or will the quote that the seai approved contractor gives me include this as well? It’s not exactly clear on their website…

Cheers

If you want to get a grant from SEAI you need to install a high efficiency boiler and get heating controls installed. Heating controls will give you the choice of heating 'zones' in your house e.g.the radiators upstairs, radiators downstairs, hot water or any combination of these. It's well worth it in my opinion.
To get the grant you need to apply before any work is started. You can also apply for a grant toward the cost of the BER. A BER is required once the work has been completed.

JohnnieK

Barack Obama wrote: »

Forgot to mention that I don;t think a combi-boiler would suit. The reason is that some of the bathrooms are a long way from the boiler and it would take a long time for the hot water to get to the tap - that's the way it is at the minute from the immersion tank anyway.

I'm open to suggestions - we have a pump electric shower only so this relies on hot water in the system.

Would there be an option available to re-locate the boiler more central for hot water distribution?

Even just putting a thermostat in the house to control the boiler would be more efficient than what you have at the moment.

Controls do make a heating system more efficient and the more of them you have the more efficient the system will be, and the way gas and oil is going I would be trying to squeeze as much out of it as possible.

Barack Obama

PMC999 wrote: »

If you want to get a grant from SEAI you need to install a high efficiency boiler and get heating controls installed. Heating controls will give you the choice of heating 'zones' in your house e.g.the radiators upstairs, radiators downstairs, hot water or any combination of these. It's well worth it in my opinion.
To get the grant you need to apply before any work is started. You can also apply for a grant toward the cost of the BER. A BER is required once the work has been completed.

How many zones would be normal for a 5 bed detched house? Was thinking 4 - d\s front and back & u\s front and back.

From the extra digging and rough quotes that I've got it looks like taking the route of the SEAI grant works out MORE expensive! I can only guess that it's because of the extra cost of the BER. I have a quote of around €2000 for new boiler and controls without the grant - €300 cheaper than I can find with the grant!

JohnnieK wrote: »

Would there be an option available to re-locate the boiler more central for hot water distribution?

Even just putting a thermostat in the house to control the boiler would be more efficient than what you have at the moment.

Controls do make a heating system more efficient and the more of them you have the more efficient the system will be, and the way gas and oil is going I would be trying to squeeze as much out of it as possible.

The boiler is on the outer wall of the utility room and that's where the vent is so I doubt that there is a better place to put it. The hot water tank itself is pertty central - the airing vupboard is in the middle of the landing.

heinbloed

How many zones would be normal for a 5 bed detched house? Was thinking 4 - d\s front and back & u\s front and back.

Install automatic radiator thermostats on every radiator and forget about inefficient zoning.

Each emitter (radiator) should be controlled individually. One gas pedal for speed controling for all cars in a certain zone would be called stupid, wastive. It's the same with the radiators in a house.
Controll them individually for as little as € 12.-to €15.- each. And increase the efficiency of the heating system by this.
This is how the majority of European central heating systems work. 'Zoning' is Irish, expensive, unreliable and inefficient. A job creation scheme for plumbers, payed dearly for by the consumer and the tax payers via the national trade deficit.

Barack Obama

Been researching the boiler and I like the look of the Baxi Megaflo System 24 HE A -
http://www.homeheatingguide.co.uk/efficiency-tables.php?model=015691

Are these good models?

DGOBS

Stay away from the megafow, especially if you suffer limescale in your area!

As for using only TRVs on your rads, they should be used in conjunction with zoning as TRVs do not give interlock to the heat emitter leaving the system prone to short cycling. Fact, not theory.

Good boilers would be the likes if Viessmann, Worchester, Intergas to name a few.

But if you want to go the mainland Europe way off you go, they have grey ideas, just look at the euro zone, clever people!

DGOBS

Stay away from the megafow, especially if you suffer limescale in your area!

As for using only TRVs on your rads, they should be used in conjunction with zoning as TRVs do not give interlock to the heat emitter leaving the system prone to short cycling. Fact, not theory.

Good boilers would be the likes if Viessmann, Worchester, Intergas to name a few.

But if you want to go the mainland Europe way off you go, they have great ideas, just look at the euro zone, clever people!

Barack Obama

Thanks for the tip DGOBS . Plenty of hard water in my area so if there's problems with the Baxa's then maybe I should avoid...

Is there any of the Worchester range in particular that anyone could recommend? How about the Worcester Greenstar 25 Si?
http://www.homeheatingguide.co.uk/efficiency-tables.php?make=Worcester

Reyman

Hi Barack,
I have the Bosch Worcester 24i installed two years now and my gas bills are way down. I researched the market thoroughly before getting it and it came out tops in every survey. I have to admit I'm a bit biased about any of those boilers that come out of the UK - on the basis that there's no real Engineering excellence there anymore. But that's just a personal opinion!
On another note I recommend you get the controls installed - they make a real difference. It allows you to heat small parts of the house in the Autumn and Spring and run the heating at full tilt when it gets really cold.
Another control that's really useful is a thermostat on the hot water cylinder. This allows you to turn on and off the water heating easily. If you just turn on the heating for an hour or two, you don't have to heat 30 gallons of water every time.
PS. I've a bungalow about 1,500 sq.ft

Barack Obama

heinbloed wrote: »

Install automatic radiator thermostats on every radiator and forget about inefficient zoning.

Each emitter (radiator) should be controlled individually. One gas pedal for speed controling for all cars in a certain zone would be called stupid, wastive. It's the same with the radiators in a house.
Controll them individually for as little as € 12.-to €15.- each. And increase the efficiency of the heating system by this.
This is how the majority of European central heating systems work. 'Zoning' is Irish, expensive, unreliable and inefficient. A job creation scheme for plumbers, payed dearly for by the consumer and the tax payers via the national trade deficit.

Great info Heinbloed - thanks. The more I ask experts, the more zoning seems to be a waste of money and I should get TRVs fitted to the radiators. Is this something I can do myself?

I'm still going to go ahead with the boiler upgrade so this should make a big difference. It looks like the SEAI grant has been suspended as well...

DGOBS

not to zone is a mistake, zoning with trvs (except in rooms with stat) is the way to maximize you potential fuel savings!

I think zoning works well, I think zoning with TRV's works even better, you need a boiler interlock so the boiler knows when it's job is done without that your TRVs will be off as they reached temperature but your boiler will continue to cycle on and off.

Barack Obama

DGOBS wrote: »

not to zone is a mistake, zoning with trvs (except in rooms with stat) is the way to maximize you potential fuel savings!

Stat? Great - another thing to add to the equation! I guess these would have to be cabled around the house and would cost a fair bit to do??

If the SEAI are removing the grant for the controls then it's going to cost anywhere between €600-€1k to get zoning installed. I doubt I would make that back tbh...

gary71 wrote: »

I think zoning works well, I think zoning with TRV's works even better, you need a boiler interlock so the boiler knows when it's job is done without that your TRVs will be off as they reached temperature but your boiler will continue to cycle on and off.

Hmmm... The guy I had quote me mentioned nothing about an interlock but that makes complete sense Gary. I better do some more checking.

Are all TRVs the same? The Honeywell VT15 seems like a good budget model - would you recommend them? From the looks of it, the entire valve is replaced so it could be a messy enough job so I'll probably get the installer to look after that for me as well.

A TRV is a device that can restrict the flow of water depending on the air temperature it senses around it or from a attached sensor, the first being the most common, they all do pretty much the same thing but the new funkier ones can come with more controllability, no TRVs i'v seen will switch off your boiler to prevent wasting fuel.

I don't fit TRV's anymore but honeywell make good stuff and TRV's are very easy to fit once the system is drained.

Have a look at:http://www.burnley.gov.uk/site/scripts/download.php?fileID=2518

DGOBS

A zoned system is useless without interlock (it's a given)

What you looking for your research is an s-plan

heinbloed

Barack Obama asks:

The more I ask experts, the more zoning seems to be a waste of money and I should get TRVs fitted to the radiators. Is this something I can do myself?

Absolutely, check the TRV manufacturer's home page, most have very good DIYer 'how-to-do-it' pages.

The radiators have to be installed and joined to the distribution system, the entire system then to be pressure proved. So the installation of the TRVs would be the heating system installer's job.
Which can be done on a DIY base as well, depending how handy Andy is

If
a.) installing a timer with the boiler and

b.) a minimum 'thermal draw' is always guaranteed there is absolutly no technical or economical reason for Irish 'zoning'. Then simply forget about it.
The 'minimum thermal draw' can be guarenteed by various ways: a buffer tank connected (wastefull, depending on the overall heating system), a radiator installed which is always open (frequently the bathroom radiator is chosen for this), the installation of TRVs which allow for a fixed minimum draw.

The smallest thermal consumer (radiator, buffer tank) determines the boiler's minimum outlet.
For example the smallest consumer consumees 2 kW then the boiler has to modulate from 2 kW upwards. The minimum output of the boiler should then be 2kW plus a bit for distribution loss.
This way no 'zoning' is necessary, each room now being an independant zone fully controlled.

Keep in mind that many posters here in the forum are not very up-to date, TRVs with a pre-set minimum draw some haven't seen, non-zoned CH heating systems are only know from home and Grandma's cottage.
Experience in modern energy management is hardly found since energy management is hardly tought anywhere on this Island.
As long as the consumer don't ask most plumbers don't bother to inform themself.

Was an energy demand calculation done ( EN12831) so far? What is the maximum demand for CH, a.)with and b.)without DHW?

DGOBS

which boiler has a minimum of 2kw?

Zoning provides 'BOILER INTERLOCK' trv's do not, it's pretty simple.

The benefit of zoning, is that different areas can have a combination of time & temperature control that interlock with the appliance, this should be complimented with TRV's to further enhance the control within the zones. This is done to maximize the fuel savings on your system. FACT

With only trvs in control, what happens when the house reaches temperature?
Why heat your water storage tank when you have no requirement for hot water?
Why heat a zone such as sleeping areas during the daytime?
Why heat the living zones of the house when your sleeping?

heinbloed

DGOBS asks:

which boiler has a minimum of 2kw?

Here again the list which you should have copied and printed out:



http://www.boards.ie/vbulletin/showthread.php?p=75244837


Choice of boilers don't seem to be your strength, DGOBS. Have you asked Viessmann about their modulating condensing oil boiler - as promised?

heinbloed

heinbloed wrote: »

Choice of boilers don't seem to be your strength, DGOBS.?

:pac::pac:

DGOBS

Most gas boilers that are available here do not modulate down as low as 2kw (either do most on that list!) and the ones that do have a very low max output

As I previously said, I will be in Viesmann in the new year (march)
But at €4500 aprox for a barely 3% increase in efficiency, I can't see a benefit, would take beyond the life expectation of the appliance to get any ROI, unless the technology gets cheaper I see no consumer benefit.

Practical installation does not seem to be yours! As most installers here seem to agree, everything looks good on paper, go pick up a spanner!

heinbloed

DGOBS wrote:

Most gas boilers that are available here do not modulate down as low as 2kw (either do most on that list!) and the ones that do have a very low max output

Every boiler is available everywhere, DGOBS. Unless you live in Northern Korea or Myanmar.
Contact ELCO directly, their smallest starts at 1.9 kW, note below. They will sell to you as well as to anyone. Unless you live in Northern Korea .....

Correction:

The smallest boiler from this company starts at 0.9kW ( THISION S )

heinbloed

heinbloed wrote: »

DGOBS wrote:


Every boiler is available everywhere, DGOBS. Unless you live in Northern Korea or Myanmar.
Contact ELCO directly, their smallest starts at 1.9 kW. They will sell to you as well as to anyone. Unless you live in Northern Korea .....

Your being silly again;) boilers have to meet a given criteria before they are sold here, did you know that a boiler made for the Italian Market wouldn't work here or one for the French Market has a different internal wiring requirement or that each boiler sold in each country must meet the local regulations, so I'm sorry to say that a lot of the stuff you link too isn't compatible with the Irish Market.

heinbloed

A boiler with a CE mark is compatible with Irish legislations.

Any competent installer/heating engineer can install it anywhere. That's what competence stands for.

A competent business man could ask the 'foreign' company about details.
The Ariston group - to which ELCO belongs - exports to over 150 nations, so their home page says.

http://www.aristonthermo.com/worldwide/world-partner/

http://www.elco.de/produkte/thision.html


There are many more small boilers out there, including combi boilers as the OP want to install.

I work for a manufacture of boilers, i'v walked around the factories more than once:cool:, I know what's required in bringing a boiler to the UK and Irish Market, so it not as simple as you think, the new cylinder with the heat pump has been held off from the UK and Irish Market for a while now until it meets the local requirements and it has a CE Mark as it's sold in the rest of Europe.

A water heater made for the European Market can't be sold in the UK without the extras to meet UK regs, a water heater from the Uk can't be fitted here as it comes with a 3 kw element, a gas boiler for the Italian Market can't be sold here as the burner holes have a different configuration, also the instruction must be in the language of the country it's being sold in and list the local installation regs, but what do I know:pac:

heinbloed

heinbloed wrote: »

A competent business man could ask the 'foreign' company about details.
The Ariston group - to which ELCO belongs - exports to over 150 nations, so their home page says.

.

Try ringing Italy about a boiler they sell there but not in Ireland, they will put you on to their local rep who would tell you "can't help you as their not sold here"

Also thinking about it if you bring in that boiler you linked to then what do you think part availability will be like, the warranty and what if their engineer wasn't good enough to work on something he's never seen before.

DGOBS

A) Available boilers to me is what I can buy locally, stocked by agents tht are here and provide support and warranty here, tht parts are available here, if I did as you suggested, what happens when they need a part, sorry mate it's minus 5 outside, your part I'll be here in a week or so!
Your quoting only the smallest boilers, what bout the full load, max and min output have to be considered, most that modulate down so low only have low max outputs so would only be unit able for a limited number of small installations unless gong into a rated houses (of which we have not many)
C) You have not answered any of the other questions raise bout interlock and demand
D) Have you ever actually installed and commissioned a heating system?

You are blinded by theory, and cant see the wood for the trees sometimes

heinbloed

DGOBS has a lot of questions concerning the laws of physics, so I try to help:

First of all, DGOBS, mark your questions with a question mark, being literate I find it easier to identify a question even if this question has hardly any structural grammar.

Like this one:

A) Available boilers to me is what I can buy locally, stocked by agents tht are here and provide support and warranty here, tht parts are available here, if I did as you suggested, what happens when they need a part, sorry mate it's minus 5 outside, your part I'll be here in a week or so!

I suppose the underlined part is a question, what " they" stands for isn't clear to me, but I give it a try:
Contact ELCO or whoever is there and ask them about sales conditions, about technical back-up. I'm not working for them and can't advise you on this issue. It is the non-idiots (greek term, no insult) who decide what to do and how to proceed.....

Second question of yours:

C) You have not answered any of the other questions raise bout interlock and demand

That is because I took them as being of a rethorical nature.

Third question of yours:

D) Have you ever actually installed and commissioned a heating system?

Yes.



Your 'expertise' is needed by gary71, he obviously does not know how a radiator thermostat works. He thinks they work in an on-off modus. Explain to him that and how TRVs work in a modulating modus, modulating between 1% and 99%.
You would not only do gary71 a favour by teaching him a valuable lesson but doing so should answer the questions you have asked about operating non-zoned CH distribution systems where TRVs are installed.

This is a method of learning, explaining a problem whilest asking a question leads to the answer. If practised by a half-ways intelligent brain tought to ask the question whilest looking at both sides of the same medal.

Now it is up to you to teach gary71 a lesson about the technical potentials of TRVs. And you'll see your own questions as asked above will be answered.

heinbloed

DGOBS seems to have a problem concerning informations about the availablity of modern heating equipment, so I have dug out some old brochure from Viessmann (September 2011):

http://www.viessmann.se/etc/medialib/internet-se/brochyrer/engelska.Par.9570.File.File.tmp/New_Developments_2011_GB.pdf

Here we can see the 1.5 kW boiler Vitodens 300-W WB3E

If we have problems making it down to the shop, DGOBS, we can use the internet as well.

You wrote here that soon after Christmas you'll see someone from Viessmann

http://www.boards.ie/vbulletin/showpost.php?p=75476179&postcount=18

whilest stating in this thread here that this would then be March.....

With this sort of professional attitude we'll be still brushing our teeth whilest others have done the job and being on the way home.

Me in your position wouldn't be to worried of getting spare parts just in time(smiley).

OP, I'm sorry for my part in ruining your tread, it seems to be a common thing now days:o

Plombier

What heinbloed is suggesting,

a. Installing a timer with the boiler.

Imagine leaving your car engine running all day just in case you might need to drive it, my car uses 1 litre per hour to idle wasted energy so I turn it off!!
As we speak the interlock technology is built into some newer cars the engine shuts down when it comes to a halt.

b. A radiator installed which is always open (frequently the bathroom radiator is chosen for this) or the installation of TRVs which allow for a fixed minimum draw. The smallest thermal consumer (radiator, buffer tank) determines the boiler's minimum outlet. For example the smallest consumer consumes 2 kW then the boiler has to modulate from 2 kW upwards

To use the energy produced by the boiler and plant heinbloed suggests overheating some or all parts of the building.
Even if the boiler modulates to 2KW this is heat energy that has to be wastefully dissipated in whatever part of the building it is pumped to.
If for example the house at design conditions (-5C) has a heat loss of 10KW, when the temperature outside is at 10C the heat loss from the building is now only 4KW if the boiler modulates down to 2KW its still producing 50% of the energy required to heat the house fully.

Even if we employ a 300ltr buffer tank to try and alleviate the problem, at the boilers minimum output the tank will be heated fully through the heating differential in less than 5mins. So either a much larger buffer tank is needed or a clever control system but if heinbloed can’t see the benefits of a simple boiler interlock then what for the concept of controls??

DGOBS

So I will ask them all again, since they were ignore earlier.....all with a ?


With only trvs in control, what happens when the house reaches temperature?
Why heat your water storage tank when you have no requirement for hot water?
Why heat a zone such as sleeping areas during the daytime?
Why heat the living zones of the house when your sleeping?

Regarding parts supply, in EXPERIENCE (of the practical nature) the imported boilers that do no have established agents here result in delays in getting components when required.

Again the only real question in the last post (you seem to have ignored) is when I queried as to how many installations you have installed and commissioned?

Of the ones you have actually had experience working on, what were the measured outcomes, when installed as you have suggested?

You see, aside from work, I love Fomula 1 racing, I could talk for hours about it, the technical aspects, driver programs, tyre wear on particular circuits...etc
But I am fully aware, if I attempted to drive a F1 car or design one, it would be a disaster!

Re TRVs, when the house reaches temperature, the boiler will short cycle and waste fuel as the will be no demand from the emitters, even with the boiler in low fire mode.
TCVs also have no demand link to the boiler, so every time the boiler is on you waste fully heat unrequited water.
Without zoning, areas of the household that do not require heating at that time period will again waste energy once the boiler is firing.

DGOBS

thought March can after Christmas, or is that different in your world too?

Unlike some, winter is my busy period, also as I am going there on the manufacturers invite, I would hardly argue with their suggested dates!

You still have not answered regarding the wasted fuel on the system you are suggesting, is it just me, or does everyone here that works daily in this environment seem to disagree with your theories?

On a foot note:
I personally would never be as ignorant to refer to anybodies literacy as you have no idea as to the difficulties a person may have, I find it both rude and offensive. In my work I come into contact with may people on a professional footing and have to deal with their literacy issues.

heinbloed

I try it with Plombier's assumptions first, I quote:

To use the energy produced by the boiler and plant heinbloed suggests overheating some or all parts of the building.

That isn't true. A small boiler won't produce more thermal energy than is lost through the fabric. So with a correct choice of components and intellectual input - as demanded by the Irish building regulations - a situation of overheating will never occure.
Prove the opposite.

Even if the boiler modulates to 2KW this is heat energy that has to be wastefully dissipated in whatever part of the building it is pumped to.

A wastage of thermal energy won't occure during the heating season. Outside the heating season the boiler won't be turned on. Since there is always a thermal loss through the fabric there is always no waste of thermal energy created by the operating boiler.
Provide a EN 12831 calculation to prove that this is wrong.

If for example the house at design conditions (-5C) has a heat loss of 10KW, when the temperature outside is at 10C the heat loss from the building is now only 4KW if the boiler modulates down to 2KW its still producing 50% of the energy required to heat the house fully.

I'm not argueing about the chosen units nor about the result in percentage but:

The penny has dropped, well done Plombier !

As long as the thermal loss through the fabric is higher than the minimum output of the radiators/boiler no thermal energy will be wasted by boiler cycling. The boiler will be providing thermal energy through the entire heating season, no cycling. It's as simple as that.

Again: an energy demand calculation according to EN 12831 must be done in all cases. Without such a very basic exercise all rule-of-thumb installations are more or less wasted.

Barack Obama

Not sure what's going on but my head is spinning! :eek:

I'm pretty sure that one of the modulators is out for me (especially at the suggested price of over €4k!). I'm going to get a 24k condensing boiler that gives 91% efficiency. Surely this is good enough?

Because this boiler is either on or off, the system surely must be able to tell it when to turn off. If fitting TRVs will not do this then zoning must be the answer? Or is that any other way of turning off the boiler automatically??

To be honest, DGOBS's 4 questions make sense to me...

heinbloed

Sorry, DGOBS, I realy took your questions to be of a rethorical nature. But you tought me otherwise, so I give it a try:

1.

With only trvs in control, what happens when the house reaches temperature?

The house won't reach temperature, that is a wrong assumption. The air temperature in the rooms (!) will reach a satisfactory level sooner or later.
And this air will at all times lose thermal energy to the colder walls and windows, will be cooled down by ventilation.
The TRV - which modulates whilest restricting the flow - will close not entirely. A TRV will go closer and closer (in lay men terms) the nearer to the desired demand the room temperature gets.
With the result that the emitted thermal energy from the radiator covers exactly the thermal loss of the air.
Like a modulating boiler the radiator is modulating it's output.

A very simple and clever invention such a TRV, one really has to read the leaflet to understand how a wax filled cartridge influences the valve.


2.

Why heat your water storage tank when you have no requirement for hot water?

I really don't know DGOBS. Read my posting again, your quoting is misleading since incomplete. Please quote entire sentences, this is a good standard in written communication.
If quotes become to long one can use " ...... " to mark a missing/non-quoted part of a text.

Example:

If quotes become ........................ part of a text.

As you can see it is important to quote correctly, otherwise the sense becomes lost.


3.

Why heat a zone such as sleeping areas during the daytime?

If the thermal loss of the room is not covered there is no heating, just a reduction of cooling. Does that make sense to you?
There are TRVs with build-in timer as well. These can be manipulated to zero-throughput when the timer demands that. Read the accompanying leaflet provided by the manufacturer.


4.

Why heat the living zones of the house when your sleeping?

Read the answer to question 3. , the thermal loss of a room not covered by a thermal input is not called heating .

Again the only real question in the last post (you seem to have ignored) is when I queried as to how many installations you have installed and commissioned?

This is an unreal question you are asking here, DGOBS. Read your last post again, I answered it already ( the answer was " Yes " ).
You did not ask for any number.
Concentrate on technical facts. Learn from those who can teach you something. And always trust your own senses, follow logic as available to you.

Of the ones you have actually had experience working on, what were the measured outcomes, when installed as you have suggested?

Since you are not asking any detailed question here (meassuring what? Units ?) I can't answer your question. I simply do not understand it.

heinbloed

Barack Obama asks:

I'm pretty sure that one of the modulators is out for me (especially at the suggested price of over €4k!). I'm going to get a 24k condensing boiler that gives 91% efficiency. Surely this is good enough?

A modulating combi condensing boiler running on gas does not have to cost more than € 800-1200.- including VAT.
A 24 k boiler is for the average household in Ireland heavily oversized, half of it would do 90% of all households in my opinion. You must be living in a circus tent (smiley).....
The boiler's minimum efficiency should be 90% or 91%, check this out. That is the legal minimum, not the optimum. Charging for such an 'incompetent' boiler working at the baseline of legality a full €4,000 is a rip-off.

Do you know the thermal energy demand of your house? Maximum demand in kW ?

Barack Obama

heinbloed wrote: »

Barack Obama asks:



A modulating combi condensing boiler running on gas does not have to cost more than € 800-1200.- including VAT.
A 24 k boiler is for the average household in Ireland heavily oversized, half of it would do 90% of all households in my opinion. You must be living in a circus tent (smiley).....
The boiler's minimum efficiency should be 90% or 91%, check this out. That is the legal minimum, not the optimum. Charging for such an 'incompetent' boiler working at the baseline of legality a full €4,000 is a rip-off.

Do you know the thermal energy demand of your house? Maximum demand in kW ?

I don;t know those figures but there are some factors -
15 year old detached house so only average insulations
Currently have a 24k Potterton Suprima 80 boiler which is never turned over halfway, and most of the time under a quarter of the way up. Now I understand that this does not lower down the burn it just increases the gap times when boiler is burning.

So, is a 24k boiler maybe too big for my needs? Do they have the control know to lessen the on time like my current boiler? I'll be getting a new timer switch as well so maybe this can do this?

A combi boiler won;t suit because of the distances of some of the bathrooms from the boiler. Also, there is a summer valve to make heating the water in the summertime a little more efficient.

I was quoted €2100 for a new boiler and 12 TRVs to be fitted and tbh I thought that was a good price. But I now see that there has to be some way to switch off the boiler if it's not necessary

Plombier

Of course heinbloed’s grammar is perfect.

First of all, DGOBS, mark your questions with a question mark, being literate I find it easier to identify a question even if this question has hardly any structural grammar.

"Writing is an act of faith, not a trick of grammar."
- E. B. White

Weather compensation makes sense where the internal heat load is depending on the time, on the date.
But not where the internal heat load is frequently changing because of changing usage of the structure, because of passive solar gain.

A standard family home with south facing windows and insulated according to building regulations will have no benefit from a weather compensation.

When the sun shines during the cold heating season and is warming the building via the windows the weather compensation unit does not sense this - it is shaded.

When cold sleet and rain hits the facade and causes cooling of the structure the weather compensation unit does not sense this - it is shaded.

If the night is clear or cloudy - the weather compensation unit does not sense this.

When the open fire is running and the kitchen in full swing the weather compensation does not sense this - it is not there but outside, shaded....

Ask a heating engineer about the exact calculations.

Or buy a magnet for the fuel pipe in your car, it's even cheaper.

As you have said yourself at any time during the heating season the building can be above the required set point (without weather compensation to prevent it) and not requiring any energy input, with a boiler turndown of 1:5 the boiler will still output 20% of maximum even there is no requirement.

Now I ask you ??? if this energy will not go wastefully into overheating the building(don’t forget the always open radiators), will you please show us with facts and figures where it end up.

Please show us your figures EN 12831 or whatever method you choose but I ask you for some solid proof not idle hearsay????

Or maybe you bought a magnet for the fuel pipe on your heating.

heinbloed

Barack Obama writes :

Currently have a 24k Potterton Suprima 80 boiler which is never turned over halfway, and most of the time under a quarter of the way up. Now I understand that this does not lower down the burn it just increases the gap times when boiler is burning.

"...which is never turned over halfway..." Does that mean your boiler resp. the burner of it is only firing half of the time there is thermal demand from the radiators?

Then this boiler is 100% oversized.

....most of the time under a quarter of the way up.

Then it is 200% oversized. Note below!

Invest a bit into professional knowledge, get a heating engineer in who will do an energy demand calculation for you.

He will tell you as well what type of boiler will suit best to your situation. Pay for this service and get the calculation (according to EN 12831) in writing.

Go for a modulating condensing boiler.


Correction
Above I stated: "Then it is 200% oversized". This is obviously wrong. Correct is: It is 300% oversized.

Barack Obama

Barack Obama wrote: »

I'm going to get a 24k condensing boiler that gives 91% efficiency. Surely this is good enough?

I would say that's perfect;)

Barack Obama wrote: »

Because this boiler is either on or off, the system surely must be able to tell it when to turn off. If fitting TRVs will not do this then zoning must be the answer? Or is that any other way of turning off the boiler automatically??

.

It comes down to whether you let the boiler continue to generate heat when none is required causing it to cycle on and off or fit a device(zoning) to tell the boiler when enough heat has been generated.

heinbloed

heinbloed wrote: »

I suppose the underlined part is a question, what " they" stands for isn't clear to me, but I give it a try:
Contact ELCO or whoever is there and ask them about sales conditions, about technical back-up. I'm not working for them and can't advise you on this issue. It is the non-idiots (greek term, no insult) who decide what to do and how to proceed.....

Elco do not have a supplier in Ireland or a service network or any parts:)

But yes that do have a CE Mark:D

Barack Obama

heinbloed wrote: »

Invest a bit into professional knowledge, get a heating engineer in who will do an energy demand calculation for you.

He will tell you as well what type of boiler will suit best to your situation. Pay for this service and get the calculation (according to EN 12831) in writing.

Go for a modulating condensing boiler.


Correction
Above I stated: "Then it is 200% oversized". This is obviously wrong. Correct is: It is 300% oversized.

Not sure how the boiler can be 300% oversized when only sometimes it is turned up a quarter way and at times (like now) it is turned up half way. If I was to get one a third the size it could not give me the required output!

I would happily go for a modulating condensing boiler if I knew more about them! Do you know of any well used makes\models in Ireland so I can do some research? There seems to be no mention of them on the manufacturer websites that I've looked at. Are they as easy to install and will all registered gas installers know how to install and configure them?

Thanks

Barack Obama

gary71 wrote: »

It comes down to whether you let the boiler continue to generate heat when none is required causing it to cycle on and off or fit a device(zoning) to tell the boiler when enough heat has been generated.

My afternoon's research has been looking at the Worcester Bosch TD200 controller and RT10 thermostat

DGOBS

Barak, you heads spinning cos as usual there is someone in the room spouting so much rubbish based on what he has rand in books, rather than working practically on heating systems tat are already installed and require upgrading as in as much as possible to conserve energy and save on fuel cost.

In an ideal world on new builds anything is possible

When retro fitting keep it simple, 3 zones if existing plumbing allows, all zones with interlock and thermostatically controlled, preferable stats with set back features especially for sleeping areas, complimented by TRVs on all rads not in rooms with that have the zone stat, couple with a good quality reliable hi efficiency modulating gas

In the words on o e greater than I, don't suffer the fools!

This board has become so bound up in crap from one man, people will soon go elsewhere for sound logical understandable advise, as all good advise become lost in pointless aguement

Worcester make good stuff as do Viessmann and Valiant. I would want a minimum of 5 years parts and labour warranty.
Heinbloed is right :eek: with the idea of getting your heat requirement worked out so the boiler can be set to match, in the UK any boilers I fitted I would be required to do that calculation send it to the gas registration body and if I'm wrong I lose my registration( no pressure) there isn't anything like that here, but most good installers will fit a boiler and configure correctly without doing a heat load calculation.

DGOBS

I don't think any installer here worth their salt would argue that inherently boilers in this country have been over sized, and that a fundamental issue such as this is long overdue a proper regulated approach to ensure boilers are sized correctly.

DGOBS

Barack, worchesters CDI boilers are magic