Thetownend.com

Any heating engineers on here?

I have a Vaillant Ecotec plus 637 boiler. The pressure is very high and pegged to the right - water is dripping out of the outside overflow through the Pressure Release Valve. An engineer has replaced the expansion vessel and checked the filling loop.

The pressure gauge is still pegged. (Note: The boiler has shown no error code at any time)

Its now been suggested that the problem is with the 20 year old 'unvented hot water cylinder'. I can't see anything obvious, like water coming out through the tundish, which is not covered by my maintenance plan and will be expensive.

Does that all sound right? Can anyone help?

 

Whenever I've had over pressure in my boiler I have bled the radiators. Have you checked them?
I'm no expert though and know nothing about your particular boiler model, so it would be worth checking first with someone who does!

Not a heating engineer but have previously overfilled the closed system on our Vaillant EcoTec Pro28 when the digital pressure gauge errored (that’s my excuse and I’m sticking to it). I just ran a hose outside from the little release valve below the radiator and opened it up periodically while checking the pressure. Doesn’t take much to bring it back down to the 1-1.5 bar range (was 3.1!).

Guessing if you’ve had a pro in that it’s not that simple but could be worth a try?

Just tried bleeding a radiator - 1/2 washing up bowl emptied and pressure on boiler is now in the green. Will wait to see what happens next.

Has your fill tap been left open?

Nope.

Its been nearly an hour now and the pressure hasn't gone up. Will leave it a couple more and keep my fingers crossed.