Hi there,

Being not trained at all in boilers, gas or plumbing I generally don't mess when we have issues but this problem seems pretty unusual so before I invest in a fix I thought I'd seek views.

Last Sunday morning the heating didn't fire up so I went to clear the error, expecting it to be low pressure or something. The error wouldn't reset (can't remember the code) so I went to scroll through the menus and the display froze. None of the buttons would work, boiler wasn't I firing up so took the main power fuse out and left it for 5 minutes. When putting the power back on the fan fired up for a few minutes and then stopped. Display still frozen showing current system temperature. 10 mins later Error 01 came up but buttons still not responding. Boiler wouldn't respond to a demand. Service reset button did nothing.

So with much protestation from the wife I took out the main and display pcbs and gave them a hoover and checked for any blown capacitors or burnt out resistors. Nothing visible wrong with the boards. Put them back in, turned the power back on and still nothing. Display still showing current temperature with no other symbols and buttons not responding. Then, with demand coming from both the heating and hot water, I pressed the service reset again....

And the boiler immediately fired up! Went through start up cycle then ramped up to 100% and stayed there. Display still showing same temperature with no burner or fan symbols showing and buttons not responding. The whole heating system got up to temperature and pump working. With no readout and boiler running at 100% I was nervous to say the least but it did turn off when I removed the demands on it. Next time I left it on longer and kept checking inlet and outlet water pipe temperatures. When the inlet got too hot to touch I thought it was time to cut it off again but by this time the radiators were boiling, way hotter than the setting we had previously. So it seems either water temp setting isn't working or there's no feedback from the temperature sensors.

We're fine with the immersion and oil filled rads at the moment, so not in a particular hurry. To me it seems like a PCB issue and probably the display PCB, since the buttons aren't responding and the water temperature setting isn't working, but a main board issue could possibly cause the control panel to act like this too.

Sorry for the long description but if anyone has any thoughts to help diagnose the problem or has had similar problem I'd be pleased to hear from you.

Many thanks,
Phil