Vaillant VCW GB 242E -

[G..]

Vaillant VCW GB 242E -

Q what is the standing pressure , measured at the tyre valve of the -small- accumulator part of the flame control servo cct ?

tnx - G.

[John Rumm]

You mean the CH expansion vessel? 0.75 bar according to the manual I have for the TURBOmax VUW 242 E, which I expect is the same in this respect.

sorry, not sure what you are asking?

[G..]

No Not the expansion tank at the rear of the boiler . this is located in the bottom compartment and is about 3 or 4 inches diameter , like a small ball , its the pressure accumalator for the gas control valve servo system ..

tnx - G.

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[John Rumm]

It may be I am looking at the wrong manual, but the closest I can see to something matching that description is:

3.7.9 DHW expansion vessel accessory A DHW expansion vessel kit (Art. No. 8070) is available as an optional accessory from Vaillant Ltd. This expansion vessel kit should be fitted to the boiler whenever either a stop valve of the loose jumper type or a non return valve are present in the cold water mains supply to the boiler (fig. 9).

Drop me an email with a valid return address, and I will send you the PDF of the manual I have.

[Malcolm]

When I replaced the diverter valve on mine, the new valve came with instructions to remove the "accumulator" or whatever it is called (part

1810-24) and discard it. If it is no longer needed I assume the pressure is not critical.

Malcolm

[G..]

There is a pressure listed , still looking for the book ....

[cynic]

The original purpose (as I understand it) of the small (shiny) DHW accumulator was to take the miniscule expansion volume of the tapwater within the boiler as it heated up to stop expansion back into the mains. As the actual expansion volume is so small the risk level to contaminating the mains is considered so low as to make it unneccesary. Even if there is a non return valve installed on the cold main inlet to the house the expansion volume will only cause a slight increase in the domestic pipework which might or might not escape through a ball float valve on a WC or similar.

[G..]

iler =A0. this

Thats a intresting point it is in that area.. still cannot find the xx book .. with the new replacement metal heat exchanger for the hot water .. then capacity is much lower

I had an idea there was a flame ctt test point ..or is that only the gas to the boiler pressure .. ?

there are pdf copys of the book about . ,

tnx - g