Help! My Ideal boiler won't switch off

[GavinJ]

Can anyone help me out on this one? I have an Ideal icos boiler M3080 for the water and the central heating. It works fine but when you turn the heating / hot water off at the controller, the boiler doesn't shut down. It might not be fired up initially but after a few mins it flares up again. You have to turn the boiler itself off to get it to stop. It was doing this intermittently and if you turned the boiler off and let it cool down for a bit, it would stay off when you turned the power back on. Now though letting it cool down doesn't work and as soon as you turn the power back on it fires up. Is this the controller or something in the boiler do you think?

 

[bengasman]

I suppose you are referring to the timer. If so, with timer off, boiler should be off, unless froststat is on. If froststat is off, should be as it is nowhere near freezing, but check, timer is dead

 

[gas4you]

Check any zone valves you have first. Sounds like it could simply be one of these with a stuck microswitch.

This would over ride any commands from the comtroller.

Check for 240V at the orange wires in the wiring center with the programmer off.

 

[frank uk]

If like alot of systems everything goes through your mzv then as the lads said ,it will be the switches stuck and as it will stop and cool down then fire up,the stat seems ok give it a wack

 

[GavinJ]

Thanks for the tips. Will have a look and see if a whack will fix it! cheers

 

[patagonia]

Gavin -

Did the whack fix it? I have the same problem, even after replacing the motor and housing. Not sure what it is you are supposed to whack. With mine the switch which is supposed to move over and go rigid when the zone thermostat switches off is permanently floppy, i.e. the valve stays open when the Z.T. turns off so the boiler continues to fire. I had concluded that the valve would have to be replaced (cog wheel worn or a wiring problem?). Apologies for intruding in someone else's thread.

 

[GavinJ]

Hi all! When I took the front off the boiler to look for things to whack, there was nowt! As mine's a condensing boiler all of the valves are in the airing cupboard as it turns out. They're Danfoss 2 way port valves and have a lever on the top that switches the valve from automatic to manual. I checked they were both in full automatic position and one wasn't, pulled it across and hey presto the boiler went off.

Worked great for two days then all of a sudden the boiler started this flaring up again. Rads stay cold but pipes in airing cupboard are hot and it sounds like the valves are running something through. Guy came to have a look at the timer and says it all looks ok- he thinks it's the frost stat. But the boiler is in the utility so does it have a frost stat????

Anyway this morning before I came to work, switched boiler on (it's been off overnight to stop it flaring up and driving me mad) and is showing a C with a flashing green light. Went to the airing cupboard and the valves sounded like they were doing something even though the timer was off for C /H and water. Pulled the levers to manual then back to automatic, valves stopped and boiler ok again!!! Showing a O with no light at all whcih is what it should do.

This points to valves to me- what do you think?? Thanks for any help / advice.

 

[gas4you]

Sounds like one of the valves is sticking.

I've had a couple of these Danfoss ones with a slightly bent manual lever, so it sticks on after the valve is supposed to have closed automatically.

 

[krayenbrink]

Hi GavinJ, know that this is an old post but did you ever resolve this as I have exactly the same issue.

Cheers
Dan