Moved House, Central Heating Issues

[av1609]

Moved in last week, gas CH fitted 1988. It is not a combi system, there is a timer/programmer but can't find a room thermostat. The heating/water comes on fine in the morning and then early evening but then it turns off and I can't get it to come back on again. I have re-programmed the timer, the CH light is on but the boiler doesn't come on so no hot radiators. I'm confused - any ideas?
It's just in the evening it seems as today I pressed the override switch in the afternoon and it came on.

 

[Bunnyman]

Maybe motor has gone in motorised valve, so u getting heating when water is called for, then when ur cylinder is heated u will lose ch

 

[bengasman]

Some more info would not go amiss.

 

[av1609]

The boiler is a Potterton Kingfisher, there doesn't seem to be a thermostat. I set the CH timer to come on 5.30am to 7.10 each morning - comes on fine, 12.00 to 12.15, again ok and 5.30 to 10.30 in the evening. The override switch let me turn the heating on during the day when at home but in the evening although the timer light says CH on the boiler doesn't come on and the rads remain cold.

 

[bengasman]

First thing to check is if it is actually wired up correctly; it sounds like they cowboyed it in and the heating is piggybacked on the dhw.

 

[D_Hailsham]

Are there more than two water pipes connected to the boiler (ignore the gas pipe)? If so you have gravity hot water.

in that case, check if you have a thermostat on the side of the Hot water cylinder - looks like this:

View media item 10596

If you have a thermostat, you will have a motorized valve near the cylinder - looks like this:

View media item 11762
Please report what you find.

 

[av1609]

Yes both of those are present

 

[D_Hailsham]

Yes both of those are present

Thanks for the info, but you have not said how many water pipes are connected to the boiler.

Also, are you sure that the motorized valve has only two pipes connected?