Problem with switching on Baxi Solo boiler

[erikw]

Hi,
We recently moved house and we now have a fairly old Baxi Solo 2 50 PF boiler with which we are having some problems.
The boiler is controlled by a (new) Drayton LP522 programmer and is programmed to come on twice a day. In the morning everything is fine the boiler comes on without a problem. In the evening we are having problems. The Drayton programmer comes on but the boiler does not. None of the lights on the boiler ( 'boiler on', 'fan on', pilot on, burner on) comes on. If we try to 'boost' it manually we are having similar problems. The Drayton switches on, we can hear a click in the boiler like something is switching but then nothing happens.
What we then try is to switch the power to the boiler off and back on. This sometimes triggers the boiler to come on (sometimes after 5-10 attempts). Another solution that sometimes works is pressing boost on the Drayton, nothing happens in the boiler, then go to the room thermostat and switch that. That is, lower the temperature dial such that the thermostat switches off, then increase the dial such that it switches on again. Sometimes this triggers the boiler to come on but not always.

The problem is very inconsistent, in the morning everything seems to be fine, it is the evenings and 'boosts' that don't work.
Needless to say that it is very annoying to come home to a cold house and then spend 15min to try to get the heating to work....
Does anyone have any ideas what the problem could be and how to fix it?
Thanks,
Erik

 

[thereisawizza]

Is the hot water affected? Sounds like possible motorised valve if hot water still works. Not a major drama to change but expensive if it then turns out to be something else. Would be worth getting someone in.

 

[casaco]

Definitely check the valve first, is it a one three port or two two ports arrangement, if its one, turn on programmer and see if lever moves up, then give it a bit of help. push it up to the limit and see if the boiler gets the switch live its waiting for. if its a two port find the heating valve and do the same thing. If that doesn't work, could be the pcb.

 

[erikw]

Thanks for the advice. The hot water is affected as well, although it is not as bad as the heating, it works more often then not, but not always. Sounds like getting someone in is the sensible thing to do.

 

[erikw]

Thanks casaco for the advice. Whereabouts in the boiler can I find these valves? Sorry, I am not that experienced with DIY'ing at boilers.

 

[casaco]

The valve or valves aren't located on the boiler, they are usually in the airing cupboard near the hot water cylinder on the 22mm pipework, very often little silver boxes or sometimes blue ones, they have levers on the side and a micro-switch inside, sometimes the electric motor doesn't wind the lever over far enough to meet the micro-switch, so if you move it manually and the boiler fires then changing the valve usually cures the problem.

 

[erikw]

The valve or valves aren't located on the boiler, they are usually in the airing cupboard near the hot water cylinder on the 22mm pipework, very often little silver boxes or sometimes blue ones, they have levers on the side and a micro-switch inside, sometimes the electric motor doesn't wind the lever over far enough to meet the micro-switch, so if you move it manually and the boiler fires then changing the valve usually cures the problem.

Great, I know now what you mean, these valves are indeed in our airing cupboard. I remember they have a slider set to AUTO or MAN as well. They are in the AUTO position at the moment. I will have a look at them this evening to see if they switch ok.