Baxi HE 105 - Pressure goes to 3bar when CH therm is set to

[chapmandb]

Hi

I have a 12 month old Baxi HE 105 (with heat store). It runs ok with the CH temp dial at up to 4 O'clock position with the pressure staying at 1.5 bar. Turn the dial to over 4 o'clock and the pressure goes up to 3bar, finally venting. It started this problem after it was serviced by a corgi registered plumbing firm, who stated they never touch the pressure vessel during the service.

Please help.

 

[chrishutt]

Sounds like an expansion vessel problem. The firm that claim to have serviced it should have checked the pre-charge pressure of the expansion vessel but are saying they didn't, so effectively admitting negligence.

You can read up on expansion vessels in the FAQ - Plumbing Tips topic.

 

[chapmandb]

Thanks

Armed with this information, I'll challenge the plumbing firm.

Cheers

 

[bengasman]

Hi

It started this problem after it was serviced by a corgi registered plumbing firm, who stated they never touch the pressure vessel during the service.

Please help.

Do they instruct all their engineers never to check the expansion vessels? Sounds like an excuse to me. expansion vessels with leaks or pressure loss are quite common so ignoring that would be rather daft.
Though not my preferred make, I found that baxi is quite okay with their after sales. Certainly worth giving them a call if the boiler is that new. Provided of course that it was installed by a man with the famous orange card. If they do come out under warranty, the engineer is bound to make your boiler as good as new.