oil boiler dhw system

sitja

Hi guys i want to change a dhw cylinder the heat exchanger is fed by an oil boiler, just wondering does this make any difference to changing a dhw heated by gas boiler.?
Or is it just the same- just turn off, drain, make changes, refill and fire up??

heinbloed

In principle not.
Make sure the heatexchanger's capacity matches the boiler output.
Get a low-modulating boiler, starting at 2 kW or the like.
Consider a cylinder with a second heat exchanger to connect to a solar thermal collector.

sitja

the boiler is already in place, just replacing an old cylinder, have changed one before but was heated by gas boiler, just want to make sure the way about doing it remains the same,

So its an open vented system, i just want to isolate cold feed to cylinder, drain cylinder, making sure boiler is off, then i isolate f&e tank, drain heating circuit. Is this method correct.

Loki98

Short answer, Yes

sitja

thanks bud, so there is not much of a difference between using an oil or gas boiler when it comes to draining down so? Only thing that has me thinking is atleast if a fault arises with gas boiler you can check the diagnostic codes but you dont have them on oil boiler do you???

Loki98

Whether your boiler is gas or oil fired is irrelevant as far as your cylinder is concerned, its just your heat source. When removing your cylinder the procedure is exactly the same.

sitja

sitja wrote: »

thanks bud, so there is not much of a difference between using an oil or gas boiler when it comes to draining down so?

NO

sitja wrote: »

Only thing that has me thinking is atleast if a fault arises with gas boiler you can check the diagnostic codes but you dont have them on oil boiler do you???

You're draining a boiler, you shouldn't need diagnostic codes to tell you if there's problem, you already know that there might be a bit of air in the system.

You are draining a boiler heat exchanger and then refilling, the heat source should have no impact, keep the boiler switched off drain and refill, if your unsure of the bleeding process for the boiler then download the manufactures instruction and follow them.

heinbloed

Modern boilers have diagnostic functions, be they oil fired or gas fired.
Make sure you understand them, it takes a code book for many to be read and understood.

heinbloed

heinbloed wrote: »

Modern boilers have diagnostic functions, be they oil fired or gas fired.
Make sure you understand them, it takes a code book for many to be read and understood.

In your working experience what problems after a drain down have you had, what fault codes have you had to identify while you have had air in the heating system and what do you find is the main differences in the controllability of the integrated electronic controls on a modern domestic gas boiler and the more simplistic controls found on a modern domestic oil boiler.

heinbloed

heinbloed wrote: »

Get a low-modulating boiler, starting at 2 kW or the like.
.

Can you explain how a modulating oil boiler works, please, as I have not seen one and everyday's a learning day.

sitja

thanks for all the replies guys, just preparing for the event of an error to occur, ,most obvious gas boiler error code i have come across is low pressure and it locks out until its brought back up.

When refilling the cylinder and heating whats the best advice to minimise air locks???

sitja

sitja wrote: »

thanks for all the replies guys, just preparing for the event of an error to occur, ,most obvious gas boiler error code i have come across is low pressure and it locks out until its brought back up.

When refilling the cylinder and heating whats the best advice to minimise air locks???

All due respect but you shouldn't need a boiler to tell you that, you emptied the boiler so you already know:D

Don't fire the boiler until your sure, bleed all bleed points starting from the lowest first, pump normally, once your happy get the pump going to create movement, if the boiler doesn't sound aerated then fire it, you will soon hear if you got it wrong but I doubt you will have a problem, oil heat exchanger tend to be bigger than gas and normally easier to fill.

Don't forget to monitor the system water quality and flush if necessary, have a look at the fernox/sentinel site for more info.

heinbloed

When refilling the cylinder and heating whats the best advice to minimise air locks???

All you have to have are automatic air valves installed at the highest points.
Air penetration (esp.with an open system) can not be avoided, so better install them.
Modern radiator thermostats have them included.The boiler should have one included as well.
So it depends on the plumbing if there are any further air valves necessary, 'camel humps' have to be 'bled', have to be equipped with air valves as a precaution since air will acumulate there.



@ gary71:

You have lot of questions about boilers and heating systems.
We have special forum about these issues.
Please start a new thread instead of high jacking existing ones.

Questions usually end with a question mark.
If you want to ask a poster something particular about what she/he has posted use the correct adress.
Ask each question in a seperate sentence, this would structure the posting and make it more readable, answerable.

heinbloed

heinbloed wrote: »

@ gary71:

You have lot of questions about boilers and heating systems.
We have special forum about these issues.
Please start a new thread instead of high jacking existing ones.

Questions usually end with a question mark.
If you want to ask a poster something particular about what she/he has posted use the correct adress.
Ask each question in a seperate sentence, this would structure the posting and make it more readable, answerable.

If i was good at English i would have a proper job so forgive me.

I would still like to know about your practical back ground is as you give guidance on a subject i have had experience of.
I'm asking questions which i feel are relevant purely as your giving instructions on the matter, what is your practical experience???? (i put a few in to make up for the ones i missed:D)

I had a look at http://www.windhager.com/int/products/oil-heating-systems/mira/ you PMed me, very clever piece of kit and i have seen nothing like this before, everydays a school day but how many funky condensing boilers with high end logic are fitted in Ireland would you say?

Billy Bunting

gary71 wrote: »

..
I'm asking questions which i feel are relevant purely as your giving instructions on the matter, what is your practical experience???? (i put a few in to make up for the ones i missed:D)

I would say thats correctly addressed and readable, but always seems to be a tough one when it comes to getting a straight answer from this poster.

heinbloed

@ gary71:

You posted:

I would still like to know about your practical back ground is as you give guidance on a subject i have had experience of.
I'm asking questions which i feel are relevant purely as your giving instructions on the matter, what is your practical experience???? (i put a few in to make up for the ones i missed)

We have a 'lonely hart corner' here on boards.ie as well, gary71.

heinbloed

heinbloed wrote: »

@ gary71:
We have a 'lonely hart corner' here on boards.ie as well, gary71.

Good luck with that then, I hope you have more luck answering questions about your practical experiance over there, if you have to rely on what you've read from books you could get found out :pac::pac::pac: