Expansion Vessels

[charliechaplinspants]

This oversizing relates to the heat output, not the water content of the system,

What is that supposed to mean?

and in any case we don't know what the OP's original heating setup was,

Correct, we don`t neither does he but generally most combis can cope quite well with anextra couple of rads added, because they are generally oversized to give a better hot water performance.

it would appear from the problem and temporary solution that it was close to the limit for the expansion vessel fitted

I`m glad that the poster in your opinion is a plumber/heating fitter.

and the addition of four extra heat emitters, with associated pipework and additional water content, has taken it over the limit, hence the need for an additional vessel.

Bull.

I'm not familiar with Aristons, having never fitted them, but I do know that some boiler manufacturers will suggest or specify an additional vessel for systems over a certain size as the one integral to the boiler is insufficient.

Sounds like you are not familiar with any combis.

 

[doitall]

You're loosing the plot Charlie

The expansion vessel don't care how big the boiler is or what the heat output is either.

It is sized as a percentage of the total system content, to take up the expansion

The more water in the pipes and radiators the bigger the vessel needs to be.

If you read the MI for any boiler they will give a maximum water content, normally around 100 Ltrs.

 

[charliechaplinspants]

How am I losing the plot? The expansion vessel in a combi is for the heating side of the boiler is that right? Since I believe that most combi boilers are sized for the hot water delivery. in other words, say I install a 30kilowatt combi because it delivers 11/12 litres per minute, yet I have three/five small rads using about how many kilowatts? 10/12 kilowatts? I still have after taking off hot water x amount, doesn`t matter, the boiler expansion vessel is still sized as a 30kw boiler, adding extra rads won`t make a difference unless you go to extreme runs and rad sizes.Hot water don`t need expansion in combi cos it goes straight thru exchanger, no need for expansion.

 

[simond]

Can`t understand everyone`s hostility, not trying to prove anyone wrong, just trying to help out with my limited knowledge, not trying to undermine anyone, giving information as I understand it, If I`m wrong, by all means correct me, I don`t intentionally give out incorrect advice unless I have been given wrong advice

I think I understand you. You are anxious to help but know nothing. And what you think you know, if it turns out to be wrong, is someone else's fault.

 

[charliechaplinspants]

You are anxious to help but know nothing. And what you think you know, if it turns out to be wrong, is someone else's fault.

Sorry you feel that way, I do try and help as best I can, like I said to Mickyg, put your money where your huge mouth is, tell me what advice I have given is wrong, otherwise shut it (as micky says).

 

[Deleted member 105431]

I think softus is back in disguise!

 

[doitall]

How am I losing the plot? The expansion vessel in a combi is for the heating side of the boiler is that right? Since I believe that most combi boilers are sized for the hot water delivery. in other words, say I install a 30kilowatt combi because it delivers 11/12 litres per minute, yet I have three/five small rads using about how many kilowatts? 10/12 kilowatts? I still have after taking off hot water x amount, doesn`t matter, the boiler expansion vessel is still sized as a 30kw boiler, adding extra rads won`t make a difference unless you go to extreme runs and rad sizes.Hot water don`t need expansion in combi cos it goes straight thru exchanger, no need for expansion.

Most of the above is irrelevant, and either you're on a wind up, or not listening.

The size of the boiler doesn't matter, it can be 10Kw or 100Kw.

It's the water that expands as it's heated, the manufacturers of boilers, not just combis fits an average size vessel for an average size house, e.g. 100Ltrs ish, the installer has to provide for additional water content, adding extra radiators can and will take it over the limit.

 

[charliechaplinspants]

You are the one not listening! if a combi is sized correctly it should be able to take a few extra rads without a problem! it`s as simple as that for god`s sake....

 

[doitall]

You are the one not listening! if a combi is sized correctly it should be able to take a few extra rads without a problem! it`s as simple as that for god`s sake....

It has nothing to do with the size of the combi

 

[doitall]

In simply terms.

100Ltrs requires 10Ltrs of expansion, and 200Ltrs requires 20Ltrs of expansion, 300Ltrs requires 30Ltrs, and so on.

Adding 4 additional rads could add say 40Ltrs of system water.

 

[holty]

think eveyone is missing the point. the EV just might need toping up usually .75 bar. simple as that. have seen many systems run on little EV charge.ps is'nt it in the new 17th edition that cables need metal plating in the wall.not pipes.

 

[charliechaplinspants]

It has everything to do with the size of the expansion vessel which will be larger in 33kilowatt boiler than a 24! thus giving the capability of a larger amount of rads, seeing as though a 33 kilowatt boiler with it`s bigger vessel is only installed because it gives a higher flow rate hot water wise and therefore be usually oversized for heating requirements, thus being able to take more rads than are probably already installed! It`s not hard is it! His boiler in my humble opinion should be able to manage with a couple of new rads added, otherwise we`d see expansion vessels being slapped on everyones walls everytime someone wanted a new rad!

 

[muggles]

It has everything to do with the size of the expansion vessel which will be larger in 33kilowatt boiler than a 24! thus giving the capability of a larger amount of rads, seeing as though a 33 kilowatt boiler with it`s bigger vessel is only installed because it gives a higher flow rate hot water wise and therefore be usually oversized for heating requirements, thus being able to take more rads than are probably already installed! It`s not hard is it! His boiler in my humble opinion should be able to manage with a couple of new rads added, otherwise we`d see expansion vessels being slapped on everyones walls everytime someone wanted a new rad!

If that is the case, then what, in your humble opinion, is the cause of the OP's problems, and what would be the solution? Also, why would creating extra expansion space in a rad have cured the problem?

 

[holty]

what the hell you on about.take it you havent fitted a heating system or know its principles.

 

[muggles]

think eveyone is missing the point. the EV just might need toping up usually .75 bar. simple as that

Good point, we seem to have missed that possibility in the process of trying to persuade our resident comedian that he's talking out of the contents of Charlie's pants

is'nt it in the new 17th edition that cables need metal plating in the wall.not pipes.

Quite possibly, but tryingtogetintocharliespants is convinced it's pipes, although as yet has failed to come up with anything official that actually says that and is taking the attitude that he's right because he says so.

EDIT: I once promised myself I'd never get into any of the daft arguments that go on on this forum between pros and morons, and now I have. Time to return to policy, I'm out...