Boiler Firing Up On It’s Own

Hi all

For the last few days our Ideal Icos HE15 boiler has been firing up even when both the hot water and and heating are in the off position on Drayton programmer.

The boiler keeps firing up every 3 minutes. It stays on for a couple of minutes and then goes off again. This cycle continues unless we turn the switch off next to the boiler/programmer which kills the power to both devices (the same fused switch powers both the boiler and programmer).

The same thing happened a couple of years ago and we replaced the programmer which fixed the problem then, however we've tried a new Drayton programmer today but the boiler still keeps firing up.

I removed the programmer altogether, switched the power back on, and sure enough every three minutes the boiler fires up and starts the cycle over again. So something else must be sending a signal to the boiler to tell it to come on.

Has anyone come across a problem like this before? I'm guessing the next stage is to get a heating engineer in to troubleshoot?

I've listed the components we've got below along with some photos.

Thanks in advance.

Chris

- Ideal Icos HE15 Boiler
- Drayton LP522 programmer
- Drayton thermostat in the hallway
- Range tribune tank in the airing cupboard

Very good chance its one of the two zone valves you have, that's the white and silver valves on the bottom pic.

Cheers. I'll give a heating engineer a call on Monday to get the problem looked at. Will report back!

it is indeed one of the zone valves playing up, either synchron motor seized or end switch stuck in closed position