When fitting new expansion vessels..

[mcniven]

Quick question ..

When you lads fit new expansion vessels to boilers which require a lot of extra work for example; remove, refitting & resealing a flue.

Do you prefer just to fit an external expansion vessel outwith the boiler?

Thanks for your input!

 

[Billy Bob Bob]

if its easier and can be hidden in a cubored yes,some boilers you may end up destroying the flue or find you cant buy new seals to put it back together

 

[quality]

I have done many and had to get a new flue but also done a few where flue has never been sealed

 

[Puddle]

Quick question ..



Do you prefer just to fit an external expansion vessel outwith the boiler?

Thanks for your input!

What's the point of that,if you have no boiler you do not need an expansion vessel

bum for ''Thanks for input''......your welcome,always a pleasure

But as said if you have room to conceal an external expansion vessel,there is no problem putting one outside of appliance,not only is labour cheaper for customer,so usually is a universal expansion vessel

It should be noted ,that you should note take the internal expansion vessel supplied with boiler,may not be sufficient for system it is being installed on,if a large system or older rads on the system,with higher water content,you have to fit an external expansion vessel as well as the one supplied with boiler

Must admit,the newer boilers are a lot easier to remove from wall to replace the internal vessel and job often does not take as long as you think

imho

 

[gaspastemania]

Puddle are you saying that foe e.g If you fit a worcester 37 cdi
on a large system you still may have to install extra expansion vessel?

 

[GQuigley67]

yes on large systems the EV inside the boiler may not be big enough, you will be able to tell by how much the pressure rises when heated, I think the EV inside boilers are ok for up to a 60L system

 

[Puddle]

Puddle are you saying that foe e.g If you fit a worcester 37 cdi
on a large system you still may have to install extra expansion vessel?

Yes ,that is correct,on the 37 cdi an extra extra expansion vessel is required when fitted on systems over 100L or if system pressure exceeds 2.65 Bar when system a max operating temp

 

[gaspastemania]

Well there you go learn something new everyday as they say !!
I was always under impression those sort of domestic boilers were designed to accom volume of water for relative model . Never heard anyone mention any different either ,,,,,only been doing this 22 years or so !!!!

 

[mcniven]

Well there you go learn something new everyday as they say !!
I was always under impression those sort of domestic boilers were designed to accom volume of water for relative model . Never heard anyone mention any different either ,,,,,only been doing this 22 years or so !!!!

You would think this would be the case eh, surely if they were being installed in a system with more volume than what the boiler is designed for, then the boiler wouldnt be the correct size in the first place? i.e they would need a bigger boiler, with a standard bigger ev!

 

[gaspastemania]

Well l;ets be honest it wouldn't be plumbing if someone didn't complicate things !!

 

[Kev the gas]

To save future problems on a combi installation in a

3 bed semi I will fit as usual.

large 3/4 bed additional vessel fitted on return setting the pressure the same as original in MI.

I try and avoid fitting system boilers now as they nearly always need an additional vessel.

The other thing to remember is the small vessel rqd for a combi, on the water main if a water meter is fitted.

 

[gaspastemania]

Is the small expansion vessel on the main a building reg now???

 

[Kev the gas]

Cant quote building regs at the mo, but most manufacturers have it in the MI.

Thinking about why they are fitted makes sense, asking a combi to heat up to 16 ltrs per minute poss more and then turning off the tap, where can the hot water expansion go?

 

[gaspastemania]

Surely tho it would make sense if the MI'S now recommend to install them then why not build them in situ within the appliance ,,,,prob to easy that ??

 

[Kev the gas]

££££££££££££££££££££££££££££££££££££££££££££££££££

Boiler pricing is so competitive, we are the engineers who design a good system, they provide the boiler extras always reqd.

 

[mikeygas]

AKA shock arrestor.

 

[GrahamM]

All the MI's will state the max water capacity the internal E/V can accommodate and some state that an additional E/V may be fitted if required for larger volume systems. On occasion in larger houses an additional vessel may be required. This does not mean the boiler is necessarily overstretched though. The internal vessel just may not have the expansion capacity for the larger property.

An indication a larger vessel would be required without knowing system capacity is, the E/V sound and pressurised to the 1 bar max. System pressure at recommended 1.5 bar. Boiler appears operate normally. Boiler ran to max temperature and the system pressure is gradually creeping closer to 3 bar.

 

[moogwai]

Ive got 2 of these to do...boiler has to come off wall as no where to put a remote one......do you charge just the same as combi swap plus materials??? not had to them before.

 

[quality]

Just charge you hourly rate plus materials

 

[GQuigley67]

I wouldnt charge the same amount as a combi swap no, as it shouldn't involve the same amount of work but I would say about half a days work anyway, would even try squeeze them both in one day if i could

 

[moogwai]

Ok thanks lads.

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