Baxi Solo firing up continuously

[cwheeler]

Hi

My boiler, a Baxi Solo, keeps firing up when neither the hot water or the heating is on. Also the outside casing of the boiler seems extremely hot.
Can somebody tell me if this is right. At night time when all heating and hot water is off the boiler continuously fires up. The heating and water are on 'run program', but the boiler seems to be working overload when these are not on (i.e. at the times when these are not required). The thermostat control on the boiler is not on maximum, probably about three quarters of the way round the dial.

I hope somebody can advise me if this is abnormal. To me, it does not seem right.

Thanks very much for your time

Cheryl

 

[D_Hailsham]

I hope somebody can advise me if this is abnormal.

Definitely not normal! The boiler should not be running when the heating has been turned off at the timer.

Which timer/programmer do you have?

Does the boiler stop if you turn the boiler stat down?

Do you have one (left pic) or two (right pic) motorized valves?
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[cwheeler]

Thanks for your reply.

Yes the boiler does go off when the boiler stat is turned down.
The timer is Honeywell.
I think (but not 100% sure) there are two motorised valved (right picture).

Also, there is sometimes a high pitched noise coming from the airing cupboard (not exactly sure from where though!).

Thanks.

C

 

[D_Hailsham]

I think (but not 100% sure) there are two motorised valved (right picture).

If so, then one of the valves is not working properly.

Do the radiators get hot overnight? If so the CH valve is faulty. If they go cold then it's the HW valve.

The motorized valves have 4 wires:brown, blue, grey and orange. The brown and blue supply the motor and are controlled by the thermostat. So when the thermostat calls for heat the motor runs and opens the valve. The grey and orange are connected internally to a switch which closes when the motor runs. This provides power, from the grey wire via the orange wire, to the boiler.

Check that you can hear the motor run when you turn the thermostat up. The lever on the side of the valve should move across and fell loose.
If that is OK, turn the stat down and the boiler should stop. The lever should return and fell stiff when you try to move it - you are trying to open the valve against a spring
.
If the boiler does not stop, the switch in the valve may be sticking. If you have a meter you can check for voltage on the Orange wire. Another way to check is to disconnect the grey wire. (Switch off the power before you fiddle!)

Also, there is sometimes a high pitched noise coming from the airing cupboard (not exactly sure from where though!).

You need to identify what is causing this noise. If there is a pump (Grundfos, Wilo etc) in the airing cupboard, this could be causing the noise. It could also explain why the boiler is getting very hot.

 

[cwheeler]

Wow - thank you so much. It is so nice to hear from somebody who actually sounds like they know what they are talking about. I will set my OH onto it when he gets home.

I really appreciate your reply.

Regards

Cheryl