Ideal Mini C24 HE cutting out once system is hot

[Rich309]

Hi, ive had a search but cant find anything with my specific problem.

I have an issue with my heating (combi boiler Ideal C24 ,pressurised system).

It’s a simple system on a ground floor flat with only 3 radiators, the radiators and boiler are about 3-4 years old and the pipework just over a year so I’m pretty confident it’s not sludge build up that’s causing the issue as it was all flushed when the new pipes were fitted

I ran the heating the other day for the first time in months, a couple of glugs and it fired up then kept going into lockout, even when the hot water was used, the hot water had been fine up until then.

I initially though it was a big airlock in the pump (they had real issues getting with lockouts ehen first installed & it was airlocks) as the heating works, heats all the radiators but the return pipe takes ages to warm and once it does the boiler shuts down as I think it overheats as the water isn’t circulating. Once it cools again it starts itself up. I spent ages trying everything to make sure there is no air in there, bleeding radiatiors, high points on the system and the pump itself.

The hot water is now working fine again and as mentioned the boiler no longer locks out, just shuts itself down until it has cooled enough.

Tried again tonight and opened the bleed screw and can see the pump spinning, the rads get very hot as they should and even the return pipe now warms up quite quickly but after 5-10 mins the boiler shuts down & restarts on its own a while later, presumably when it's cooled.

Any ideas please?

 

[Agile]

Tried again tonight and opened the bleed screw and can see the pump spinning, the rads get very hot as they should and even the return pipe now warms up quite quickly but after 5-10 mins the boiler shuts down & restarts on its own a while later, presumably when it's cooled.

Any ideas please?

So why do you feel there is anything wrong with what its doing now?

Tony

 

[Rich309]

Thanks for your reply.

The thermostat in the living room is still on and hasn’t reached temperature.

I assumed the boiler would fire constantly until the temp is reached? Or is the boiler firing related to the max radiator heat and it will keep doing the on off thing to ensure they are at max heat but not over hot until the thermostat temp is reached?

It sounds like I might have done ok getting it running again but just didn’t quite understand how it should operate normally.

 

[Agile]

The boiler only fires until the flow temperature is reached and then it goes off for a preset anti cycle delay of about three min.

There is a CH power output setting in the boiler which should have been adjusted at installation but your installer was obviously lazy or stupid and did not bother.

You should have it set correct when the boiler is next serviced.

Tony