Baxi boiler problem?

[claneyuk]

I have recently moved into a new property and had accidentally left the hot water on continuous for 4 days. When I got back, the boiler was still running and the bathroom was in a mess. The ceiling was soaking with condensed water and the temperature up there was very hot.

Naturally I turned the boiler off. When needing to use the boiler again to get some hot water, I left it on for a couple of hours and the boiler never seemed to turn off. However I noticed that the boiler seemed to be louder and there seems a lot of noise coming from it (sounds like hot water emptying from the boiler and going into the storage tank in the bathroom?). Again I went to the bathroom and again the ceiling was full of condensed water. I assume the boiler is feeding in hot water and doesn't cut out when it is not needed. Is this normal? I usually leave the timer on continuous until I think I have enough hot water. Never that the bathroom problem until I had left the boiler on for four days in a row. Got lots of hot water though.

Boiler is Baxi bermuda 401 back boiler, age not known but I think within last 10 years, possibly even 5.

Any thoughts?

 

[croydoncorgi]

I assume the boiler is feeding in hot water and doesn't cut out when it is not needed. Is this normal?

Absolutely not!!
From the sound of it, you may have multiple failures: the thermostat on the hot water cylinder (I HOPE you have one!) may have jammed on and at the same time the pump has failed, or some similar combination possibly also involving the boiler's own thermostat.

I imagine the condensation in your bathroom originated in the F&E tank for the system, which got hot because water from the overheating boiler was recirculating back into it.

This is mostly bad news and I would strongly advise you to call a heating engineer to do a proper diagnosis and repair.

 

[ChrisR]

Or , with just a bust boiler stat, the HWcyl could get to boiling point, setting up a circulation loop withthe water above it in the supply cistern, all going round giving off "steam".
Check the vent (up and over loopy) pipe from the hw cyl isn't touching the water in the supply CW cistern.

 

[claneyuk]

Thanks for that. The pump was busted. But it appears the whole system is quite corroded and the sludge clogged up the pump. Lots of spending to commence. Any idea how much a power flush should cost?