Baxi Bermuda no CH but HW working

[vonsworld]

Hi
My elderly Dad has been in hospital for 6 weeks and when he returned home we found the central heating from his Baxi back boiler is not working. It was fine before he went away.

When you turn on the hot water it works fine, the boiler fires up and you can hear the water and pump running, but turn on the central heating and nothing happens.

The CH room thermostat appears to be OK, you can hear it click on and off at the room temperature.

Any suggestions please, since we can't get an engineer until after Easter.

 

[gas112]

in the airing cupboard is there two electrical valves attached to pipe work by the pump , possibly 1 with 3 connections

 

[Harry Bloomfield]

The CH room thermostat appears to be OK, you can hear it click on and off at the room temperature.

Any suggestions please, since we can't get an engineer until after Easter.

Ensure it is enabled via the timer, to run the central heating first.

Does it have a 3-port valve, or possible two 2-port valves, to switch the heated water flow, between HW and CH? This would likely be in the airing cupboard, if you have one, where the hot water cylinder is located. These valves, sometimes stick. It might be worth giving it a sharp tap on top, with your hand, it often frees them.

 

[vonsworld]

Thanks for your replies, there is one Honeywell valve. If that is stuck in the HW position, would that stop the boiler firing up and pump running when CH is selected on the timer? Since nothing happens when you switch on the CH.

I'll try giving it a knock.

 

[Exedon]

First suspect 3 port valve try switching of power to heating system and see if valve spring returns.
Honeywell have a really good smart phone wiring app which includes a fault finding guide.

 

[Harry Bloomfield]

f that is stuck in the HW position, would that stop the boiler firing up and pump running when CH is selected on the timer?

If there is only the one valve, with the pipework of the valve, forming a T shape - then it is a 3-port valve.

Valves sticking, are a common problem, often it is the electrical part on top of the actual water valve, which sticks - called the actuator. Many valves, have a separately replaceable actuator, with the actuator bolted to the valve, by a couple of bolts, or screws, making replacement the work of minutes.

Worth checking the condition of the water valve, before going down that route. If you take the actuator off the valve, you will see the D shaped valve spindle, poking up. There should be no obvious signs of leakage around the spindle, and you should almost be able to rotate the spindle with your fingertips, though pliers might make it easier.

 

[CountryFan]

Try putting them both on together from cold and feel if the radiators heat up, if they do, then suspect the faulty motorised valve.