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Expansion vessel on betacom4?

Anyone help?
Should an expansion vessel on a betacom4 boiler fitted 5 months ago need pumping up and if so could this be causing the gradual pressure loss in the system as I can't find any leaks anywhere but am having to top up system every week . Top up to 1.3 after bleeding radiators, week later dropped to 0.9!
Any advice much appreciated.
Thanks Rootosh

4 Answers from MyBuilder Plumbers

Best Answer

This may depend on wether the size of the vessel is adequate for the overall system water volume. In many cases an additional vessel may need to be fitted in accordance with the boiler manufacturers advice. Often this not allowed for when going for the cheapest quote for a boiler replacement. It can also play a role in premature failure of a boiler. So yes it entirely feasible.


Answered 19th Jan 2020

Hi the expansion vessel shouldn’t need re charging after 5 months it could be a faulty vessel , it should still be under a guarantee I’d like at replacing it under the warranty
This would explain why the system is losing pressure if it’s not the vessel there is definitely a leak on the system done where


Answered 19th Jan 2020

You'll gain pressure on heating and lose pressure on contraction naturally during on off periods.
After installation, air from boiler and radiators relieved.
Expansion vessel factory set pre-charged from factory?
If needed to ADD more "AIR" there either isnt enough expansion to acomodate full power for ALL radiators.
Hope this helps


Answered 29th Jan 2020

If you have a faulty pressure vessel then it won't be able to take the pressure rise when the boiler is on. The key indicator is that the pressure gauge will rise to 3 bar or above which will cause the pressure relief valve to open, you may notice water trickling from the pipe out side


Answered 29th Jan 2020

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