Is it possible to fit a back boiler to an existing fire back?

gifted

shane0007 wrote: »

Apologies. Still in holiday mode ... I wish....

In answer to your question there is no circulation in that part of the system when the oil boiler only is on, but of course when both system are on, there will be acceptable circulation in both circuits.

OFTEC reference: Book 4 (3.3.1) General Paragraph 2

"The feed and expansion pipe must be able to keep the boiler full of water no matter what happens to any valves or controls fitted to the system. Therefore, no valves are permitted to be fitted within the feed and expansion pipework."

I hope this now answers your questions and I think we have flogged this one enough. This is basic stuff and should be common knowledge for trained competent persons. Good design will always result in a reliable and trouble-free system. It is not my place to warrant or condone a practice that is due to another installer, another time, another etc, etc. but I can only comment on what is best practice and what should be done when found. I am sure if a poorly installed system is pointed out to client and the issues that could potentially arise from that, then most clients will most likely opt for the better installation. It will most definitely result in further referral work and duly so.

I think you will find that this is Heat Loss through Floors...read the book properly,,its fairly easy to follow...I,ve followed your sketch and I believe your system is seriously flawed..but what would i know.. ..enjoyed this discussion

shane0007

gifted wrote: »

I think you will find that this is Heat Loss through Floors...read the book properly,,its fairly easy to follow...I,ve followed your sketch and I believe your system is seriously flawed..but what would i know.. ..enjoyed this discussion

No, I think you have an out of date OFTEC Book 4. There is no mention of Heat Loss Through Floors in the section that I have quoted. I have quoted word for word and it seems pretty clear to me. The new edition is the 2010 Edition, so you may quite possibly find that my reading is fine and indeed, it is easy to follow.

Your beliefs may well lead you to that conclusion, but that is your entitlement and I cannot argue with that. Carry on installing the way you have been. Of course, sure it will be grand....

gifted

shane0007 wrote: »

No, I think you have an out of date OFTEC Book 4. There is no mention of Heat Loss Through Floors in the section that I have quoted. I have quoted word for word and it seems pretty clear to me. The new edition is the 2010 Edition, so you may quite possibly find that my reading is fine and indeed, it is easy to follow.

Your beliefs may well lead you to that conclusion, but that is your entitlement and I cannot argue with that. Carry on installing the way you have been. Of course, sure it will be grand....

Don't work on houses..leave that to the domestic plumbers ...

shane0007

gifted wrote: »

Don't work on houses..leave that to the domestic plumbers ...

Hmmm....

gifted

but love a good discussion about plumbing..:D

John_Harrington

Is there any chance someone can take a quick look at the attached diagram and let me know if it is a) standard and b) how do I prevent the push against each other when both the stove and the boiler are on at the same time?
Thanks,
John.:pac:

shane0007

What is the common?
What is the distance between the attic flow pipes and the f & e tank?
Adjusting the flow pipes to upstairs is incorrect.
The incorrect pipe work is around this "common" area. Please explain.

John_Harrington

The common is described to me by the plumber as a common pipe that feeds a number of others, it is in the hot-press.

The distance between the attic flow pipes and the f & e tank is about 10 feet, I think.

What do you suggest around the adjustment as the radiators should be fed from the radiator main circuit, not the hot water one.

I am still struggling with the plumber's view that the boiler or the stove can be on only one at a time or the flows will push against each other, surely this is not the case?
Thanks for your help,
John.

shane0007

John_Harrington wrote: »

The common is described to me by the plumber as a common pipe that feeds a number of others, it is in the hot-press.

The distance between the attic flow pipes and the f & e tank is about 10 feet, I think.

What do you suggest around the adjustment as the radiators should be fed from the radiator main circuit, not the hot water one.

I am still struggling with the plumber's view that the boiler or the stove can be on only one at a time or the flows will push against each other, surely this is not the case?
Thanks for your help,
John.

It will never work plumbed the way it is. The two pumps are working against each other so the heat cannot go anywhere.
I also cannot see you having 10ft from the flow pipes in the attic to the f & e tank in the attic. From your sketch, the heating pipes are going across the attic.
It will cause air being sucked into the system whenever the pump starts up temporarily. This will lead to eventually sludge and degrading of your system, not to mention continuous air in your system.
The system needs to be completely re-designed.

jimjimt

My deductions from the drawing.

He is trying to heat the hot water on the oil side through a gravity circuit. Will not work.

Common is showing common returns and both pumps on the return for the radiators.

The stove is using diagonal connections. One for gravity which will not work. Because of height and distance. The other connection for rads. The stove is heating down stairs radiators only. For he will be disconnecting upstairs radiators.

corkgsxr

Is the biggest problem that if power cut there's no gravity circuit. Don't matter if it works or not, it's not safe

John_Harrington

Shane, I am not a plumber and take you at your word. I would say that the 10ft distance is right, and yes, air locks are a constant issue.

On Jims comment re "Common is showing common returns and both pumps on the return for the radiators." - yes is the answer.

Would anyone be prepared to do an edit on my drawing to tell me, to tell my plumber, how to do it the right way? I am not too sure why he is taking this view, he is a qualified plumber and a decent bloke.

Regards,
John.

shane0007

To be honest, it would be difficult to re-draw without seeing the installation as what I draw may not be able to be installed because of the demographics of the building.
A few pointers: the oil boiler flow and return should be a fully pumped circuit.
There is no open vent safety pipe from the oil side.
I would have installed the expansion to the cylinder return on the solid fuel side.
The two pumps are fighting against each other. I would move the oil one to the oil flow but have the vent behind it.
Connect upstairs circuit to be heated by both systems unless the solid fuel boiler is very undersized.
Gravity circuits look way way too long.
It's a bit of a mess really.

corkgsxr

shane0007 wrote: »

To be honest, it would be difficult to re-draw without seeing the installation as what I draw may not be able to be installed because of the demographics of the building.
A few pointers: the oil boiler flow and return should be a fully pumped circuit.
There is no open vent safety pipe from the oil side.
I would have installed the expansion to the cylinder return on the solid fuel side.
The two pumps are fighting against each other. I would move the oil one to the oil flow but have the vent behind it.
Connect upstairs circuit to be heated by both systems unless the solid fuel boiler is very undersized.
Gravity circuits look way way too long.
It's a bit of a mess really.

It can't have a gravity circuit with the non return valve can it? Granted its flap type but gravity don't have much push. Or slow it down so much youd never dissipate much heat

shane0007

Where did I say anything about having a non-return valve on the primary circuit? The primary gravity circuit can never have any valves, flap type or not, nor a pump, nor any restriction.
At the moment there is no gravity circuit anywhere on the installation.

corkgsxr

shane0007 wrote: »

Where did I say anything about having a non-return valve on the primary circuit? The primary gravity circuit can never have any valves, flap type or not, nor a pump, nor any restriction.
At the moment there is no gravity circuit anywhere on the installation.

Calm down, I'm not arguing just asking.

John_Harrington

Gents, particularly Shane, hope you can make a stab at a revised diagram as I am not too sure I understand your recommendations. I have attached the jpeg revised diagram, but if you have Visio I can upload or send you the raw visio file for editing also. Quid pro Quo is I will help you with any computer problem, if you have one.
Thanks,
John.

shane0007

There is nothing different only notes added! Is that correct?

Sorry ignore that, I misread your post. Sorry I do not have Visio. I would have to draw from scratch.

shane0007

What you are trying to achieve or as near as possible, is to get the system to as near as possible the diagram I drew & posted earlier in the thread back in February. However, since you have 4 trappings per on the stove, it is better to utilise these. No need for them in the oil boiler unless you want to install another pump for DHW.

jimjimt

The first step would be to get the oil side setup.

Make the hot water fully pump on the oil side.
Remove and blank the expansion pipe from the oil side and install a pressure vessel. This will eliminate one possible source of air intake. The pressure vessel will be your expansion.
Their is never a problem having circulating pumps on the return. Their working perfect this way for me over the last 22 years with out issue anywhere.

One could argue if the pumps are on the return they will pull from the other.
You can argue if they are on the flow they will push into each other.
Pumps work better on the return due to cooler water passing through them.

As for the stove and gravity.One would have to be their to see if it is possible.
The cylinder has to be close to stove to get a good gravity feed fully explained in the below link.

Go to the link below and go to page 7. Nice diagram to help you on your way. Get your plumber to read it and all will be sorted.

http://www.rayburn-web.co.uk/Prodin/Aga%20Obsolete%20stoves/Aga%20Much%20Wenlock%20sf%20boiler%20stove.pdf

WARNING !! anyone who does not like pumps and non return valves on the return please look away now and do not download !!

John_Harrington

Shane, what 2 changes would you make as highest impacting? My problem is I paid plumber to sort out heating when stove went in a few months ago. He made a few changes, which had to be reversed to reflect what was a working backboiler system on a fire. The piping now reflect the way it was when fire place with b'boiler, and working, but having issues mentioned. I expected the right work to be when the stove was put in, but you know the way it goes, and I've no cash left, and and and....

shane0007

jimjimt wrote: »

The first step would be to get the oil side setup.

Make the hot water fully pump on the oil side.
Remove and blank the expansion pipe from the oil side and install a pressure vessel. This will eliminate one possible source of air intake. The pressure vessel will be your expansion.
Their is never a problem having circulating pumps on the return. Their working perfect this way for me over the last 22 years with out issue anywhere.

One could argue if the pumps are on the return they will pull from the other.
You can argue if they are on the flow they will push into each other.
Pumps work better on the return due to cooler water passing through them.

As for the stove and gravity.One would have to be their to see if it is possible.
The cylinder has to be close to stove to get a good gravity feed fully explained in the below link.

Go to the link below and go to page 7. Nice diagram to help you on your way. Get your plumber to read it and all will be sorted.

http://www.rayburn-web.co.uk/Prodin/Aga%20Obsolete%20stoves/Aga%20Much%20Wenlock%20sf%20boiler%20stove.pdf

WARNING !! anyone who does not like pumps and non return valves on the return please look away now and do not download !!

The cooker in that drawing is not solid fuel. It is oil! Therefore is not a solid fuel primary circuit.
They have a couple of mistakes in it. Firstly, you cannot have 2 f & e pipes as this will create a circuit of flow between the two sides of the system and heat will be lost through the f & e tank. Only one should be installed but both systems should have access to it.
Secondly, I would not put the 2 pumps on the returns, unless the pipe work to the is double the size diameter. Each pump will fight one another. It is better to fit the solid fuel one on the return and the oil side on the flow with a 2nd ovsp behind it.
It was an old myth that pumps last longer on the return, perhaps in days gone by, but decent quality pumps can easily handle the heat on the flow.

shane0007

John_Harrington wrote: »

Shane, what 2 changes would you make as highest impacting? My problem is I paid plumber to sort out heating when stove went in a few months ago. He made a few changes, which had to be reversed to reflect what was a working backboiler system on a fire. The piping now reflect the way it was when fire place with b'boiler, and working, but having issues mentioned. I expected the right work to be when the stove was put in, but you know the way it goes, and I've no cash left, and and and....

Again difficult to say without seeing the installation. Some installation parameters are just not suitable for solid fuel and therefore if it cannot be installed correctly then it should have been installed in the first instance.

jimjimt

Good man Shane. Will you forward an email to Aga , Rayburn and Stanley and explain to them their doing it all wrong.

shane0007

Please do. I would love to see a system with 2 feed and expansion pipes that operates correctly and does not act as a through pipe within the system!
Secondly, if I have 2 pumps fitted on 3/4" pipe work that can pump circa 6 litres per minute each and I can only get 8 litres per minute through another 3/4" pipe that is feeding both pumps, what will happen?
If one is on the flow and the other is on the return, they will assist each other and work in unison. No confliction, no banging. I am not saying it won't work, but a lot of the system parameters can affect it.

jimjimt

They do recommend 28mm pipe to be connected. Cold feeds are in front of the pumps. No conflict.

In the case of that gentleman. His system is already setup for pumps on the return. He would have to adopt the drawing a little to suit his house.

It also gives him a good setup of an oil system and solid fuel system combined with the limits of a gravity system.

If it was me I would leave out the cold feed on the oil side. If it was an oil boiler (not an oil cooker)I would use a expansion vessel instead of an expansion pipe most oil boilers are in a position that cannot get an expansion pipe over the f+e tank.

But by right you are meant to have a cold feed for each appliance with the use of non return valves !!

The main reason for pumps on the return is not as such about the temperature of the water. But has water rises in temperature it become lighter/looser. If you have a failed high limit stat or other the pump will have nothing to pump. In the case of big heavy metal heat sink cooker it is a must.The return water is always cooler and easier to pump. More torque in pumping 50-60c than pumping 70c plus. Also good with the use of back boilers.

Another consideration and only if their is a lot of pex pipe involved would be thermal shock on the pipe work due to a combine system.

shane0007

jimjimt wrote: »

They do recommend 28mm pipe to be connected. Cold feeds are in front of the pumps. No conflict.

The pumps are pulling from the rads which is secondary circuit which is 3/4". Only the primary circuit is recommended to be 1".

jimjimt wrote: »

If it was me I would leave out the cold feed on the oil side.

You mean you are agreeing with me, lol!

jimjimt wrote: »

But by right you are meant to have a cold feed for each appliance with the use of non return valves !!

I disagree. You can only have one f & e pipe and on no account can any type of valve be fitted to it. What if the non-return valve stuck closed? You are solely relying on the ovsp. I would imagine that the f & e tank will overheat from scalding water being pumped over the ovsp and potentially melt the tank! A gate valve is not even allowed on it.

jimjimt wrote: »

The main reason for pumps on the return is not as such about the temperature of the water. But has water rises in temperature it become lighter/looser. If you have a failed high limit stat or other the pump will have nothing to pump. In the case of big heavy metal heat sink cooker it is a must.The return water is always cooler and easier to pump. More torque in pumping 50-60c than pumping 70c plus. Also good with the use of back boilers.

Yes perhaps with certain types of units but with standard domestic oil boilers it is best on the flow. The main reason is that you can place the ovsp then the f & e pipe (within 150mm of each other to create the neutral point) and then the circulator. This ensures the system is completely in positive pressure, rather than in negative pressure. The other advantage is when combined with solid fuel, it assists the two system circulation and the 2 systems can be on at the same time. How many combination systems do you here the homeowner complaining about when they have them both on, the pipes bang! Take a look a closer look and you will generally find the pumps are fighting each other.

jimjimt

How many combination systems do you here the homeowner complaining about when they have them both on, the pipes bang!

Never when both pumps on the return.

We will keep each other in business. For every time I see pumps on the flow I change them to the returns. Then you can change them back.

I am also in shock "Shane" disagreeing with manufacturer recommendations who are OFTEC accredited.

When you fit or service a gas boiler and the pump is on the return do you switch it to the flow ?

shane0007

jimjimt wrote: »

We will keep each other in business. For every time I see pumps on the flow I change them to the returns. Then you can change them back.

Lol!

jimjimt wrote: »

I am also in shock "Shane" disagreeing with manufacturer recommendations who are OFTEC accredited.

I bet that is a misprint. Think about it, what will happen even when the oil boiler is on, what is to stop circulation from the oil f & e over through the solid fuel f & e pipe. It's nuts. I bet if you ring them, it would be a different storey.

jimjimt wrote: »

When you fit or service a gas boiler and the pump is on the return do you switch it to the flow ?

That is on a system boiler which is pressurised and the neutral point in a pressurised system is precisely half round the system, therefore one side is exactly in positive pressure and the other is in negative, so it does not matter if the pump is on the flow or the return.

shane0007

http://www.solidfuel.co.uk/pdfs/link_up.pdf

Even have a gander at this link up. A neutraliser used as the neutral point but the same principle. One f & e pipe.

jimjimt

I bet that is a misprint. Think about it, what will happen even when the oil boiler is on, what is to stop circulation from the oil f & e over through the solid fuel f & e pipe. It's nuts. I bet if you ring them, it would be a different storey.

I can forward more misprints my manufacturers if you require.


I am in Love with Dunsley.


Gas boilers for years and years had the pump on the flow but then change it to the return ? Why ?

Ever since they did less pumps were burnt out.

shane0007

jimjimt wrote: »

I can forward more misprints my manufacturers if you require.

Please do. I would love to see them as that is the only one I have ever seen piped like that.

jimjimt wrote: »

I am in Love with Dunsley.

You were not supposed to see or take any notice of that....:(

jimjimt wrote: »

Gas boilers for years and years had the pump on the flow but then change it to the return ? Why ?

Ever since they did less pumps were burnt out.

Perhaps you are correct, but I cannot see any other reason only but additional heat, as in a pressurized system, it does not matter, then it makes sense to put on the return.
On the other hand, in an open vented system, the pump position in relation to the osvp and the f & e expansion pipe is critical and any good design will have it on the flow for oil. Why would you have the whole of the system in negative pressure when it can sensibly be in positive. Less air issues, eliminating any chance of pump over, neutral point is minimal, etc.
Solid fuel, the pump is always going to on the secondary circuit and if on the flow, the cylinder will not heat effectively. On the return, it will pull the flow through the cylinder and in conjunction with an injector tee, it should heat the water satisfactorily.

Off to bed, fingys tired.

shane0007

Another possible and more likely reason gas boiler manufacturers have the pump on the return in a system boiler is to ensure the AAV's are in positive pressure. This is because if or should I say when they leak/fail, air/water will be pumped out rather than air being sucked into the system.

jimjimt

Another possible and more likely reason gas boiler manufacturers have the pump on the return in a system boiler is to ensure the AAV's are in positive pressure. This is because if or should I say when they leak/fail, air/water will be pumped out rather than air being sucked into the system.

A very good point !! Air getting in and burning out the circ pump.
Like the air vent on top of an oil boiler and the pump on the flow.
Like an expansion pipe on a oil boiler and pump on the flow too close to the expansion pipe sucking in the air when circuits shut down.

Lot of funky stuff in that Dunsley box.
Combining a gas boiler to solid fuel.
A pump on a return.
Not directly having a gravity feed to the cylinder but instead going through a third party box.
No direct path into the radiator system from the solid fuel.

She will blow for sure Scottie !!!

I bet you it all works nicely.

The main thing is not to shoot at the hips when you see two pumps on the return.

The reason in the AGA diagram the cold feeds work they are in front of the pump. The force of gravity/head from f+e tank and and the pump will be at the end of its curve and doing work else where will not allow the pump to pump up to the tank on either side.
Also the reason for a cold feed on each appliance is to allow the system to expand naturally into the tank. If no cold feed present the only where else to expand is to spurt out the expansion pipe periodically.

There is more than one way to plumb a heating system.

jimjimt

Taken from a stanley cooker manual. To be fair they also show systems with the pump on the flow.
I do believe you know some one who use to work and design for Stanley.
Most of stanley solid fuel stoves manuals show pumps on the return.

Any way of to service an oil boiler and get system ready for cleaning to try out my shiny new Magna Cleanse unit later in the week and not oftec registered :eek:

shane0007

jimjimt wrote: »

Any way of to service an oil boiler and get system ready for cleaning to try out my shiny new Magna Cleanse unit later in the week and not oftec registered :eek:

???

andredorcia

Hello

I would like to ask I'm not sure if that is the right name for open fire back boiler? What I'm looking for is ,I would like to keep my current open fireplace in living room and just add something that will give some warm in to my radiators and will make my water also hot too I have currently central heating in my house, i would love to keep that central heating and just if possiblle to add this, as we only now start using our fireplaces in the rLeavingroom. I'm just wondering how much it will cost me to do something like this
and if that is even possiblle?if possilbe sent me an email,as im mostly in work

Thank you
Regards

Dtp1979

andredorcia wrote: »

Hello

I would like to ask I'm not sure if that is the right name for open fire back boiler? What I'm looking for is ,I would like to keep my current open fireplace in living room and just add something that will give some warm in to my radiators and will make my water also hot too I have currently central heating in my house, i would love to keep that central heating and just if possiblle to add this, as we only now start using our fireplaces in the rLeavingroom. I'm just wondering how much it will cost me to do something like this
and if that is even possiblle?if possilbe sent me an email,as im mostly in work

Thank you
Regards

Have you oil or gas central heating?

andredorcia

Dtp1979 wrote: »

Have you oil or gas central heating?

Hi
we have currently gas heating in our house, and we would like to keep it

Dtp1979

andredorcia wrote: »

Hi
we have currently gas heating in our house, and we would like to keep it

Yes it is possible to do what your suggesting but there's a lot of factors to consider and only by looking at the actual job is the only way to know for sure what's involved

andredorcia

Dtp1979 wrote: »

Yes it is possible to do what your suggesting but there's a lot of factors to consider and only by looking at the actual job is the only way to know for sure what's involved

Thank you Dtp1979
and by any chance would you know to who i should direct this work to be done? because i sent already 10emails to different companies but unfortunatelly none of them is doing this?
i will add that im from co.Kildare(kildare Town), and maybe it's only in here but couldn't find anyone
Thank you again

Dtp1979

andredorcia wrote: »

Thank you Dtp1979
and by any chance would you know to who i should direct this work to be done? because i sent already 10emails to different companies but unfortunatelly none of them is doing this?
i will add that im from co.Kildare(kildare Town), and maybe it's only in here but couldn't find anyone
Thank you again

Try shane0007 on here.

jimf

Dtp1979 wrote: »

Try shane0007 on here.

+1

stovemad

what your asking is no problem to do just wondering have u a copper cylinder in your hotpress? or maybe is it a combi boiler you have?

andredorcia

stovemad wrote: »

what your asking is no problem to do just wondering have u a copper cylinder in your hotpress? or maybe is it a combi boiler you have?

Hiya
the one i have in my house is the regular traditional boiler.
is that changing anything?