BAXI Bermuda HW OK NO CH

[morris1]

I have a Baxi Bermuda back boiler, gravity fed central heating system, which provides excellent heated water (via tank). Unfortunately until about 3 weeks ago the central heating has stopped working. The timer works ok when asking for HW and the boiler fires ok, however when it switches to CH there is no heating in the radiators.

On the weekend I drained the central heating against a suspision that maybe there is sludge in the radiators (especially in the radiators on the ground floor which rarely became hot on a normal day when everything was ok). The 2 radiators were taken off and flushed, there was some sludge (black water) but nothing major. I reinstalled the radiators and filled the system hoping for some luck. nothing has changed HW ok no CH.

I guess the next step is the pump. When the timer asks for HW it appears the pump seems to be working because it gets hot around it, athough the HW system doesn't need the pump because the heated water rises due to expansion of the heated water.

So the question is, Could this be a problem with the pump or thermostat.

PS the room thermostat doesn't trigger the boiler off either (I've checked the room thermostat and this appears ok and there is power going to it)


Any help would be appreciated.

 

[ollski]

I imagine you mean a standard open vented system with , I would guess , a 3 port motorized valve. This will be the faulty component in that it's not making the microswitches. You may need a complete new valve, maybe a new valve head or maybe just the motor which sits inside it depends on the type of valve and condition of the system water.

 

[morris1]

I thought about the motorised valve and checked to where and what type it is. Basically it doesn't apper to be a 3-way valve. It is definitely is a 2-way motorised valve. It doesn't appear to make a difference if I switch the leaver between automatic and manual