heatline c28 combi boiler

[Rajdeep Singh]

Hello everybody,
New to this forum and looking for some advice. I have a C28 combi heatline boiler and have the following problem

When set on heating and water and I put the heating on, within 30 seconds the burners / pilot light cuts out and the heating doesnt warm up. However when you run the taps on hot water the boiler lights up and stays on with the water being hot. The pilot light / burner doesn't go out.

What is causing the problem for the burner / pilot light go out when the heating is on?
I have already replaced the three port valve with no success.

Can you please please help
thanks

 

[diamondgas]

:Welcome: to the forum Rajdeep 🙂

Does the boiler light on heating only, any lights flashing? Do you ge any heat at all ?

 

[JAP&H]

Hi Rajdeep, welcome.

Could be primary thermistor, easy enough to check with multimeter.

 

[jtsplumbing]

I know it's a silly question , but did you open the isolating valves after you replaced 3 port valve ?? have you got any flashing led's (Lights) flashing on boiler ?

 

[Rajdeep Singh]

No flashing LEDs at all.
No heating at all the pipe near the overheat safety thermostat gets very hot! But soon as the burner / pilot light cuts out the pipes reduce in heat
I didn't open the isolating valves either should I have done this?
How do u do this?

 

[diamondgas]

By isolating valves do you mean the onesw under the boiler on the heating pipes?

 

[glenno1]

It sound like you are out of your depth .Without being rude i think you need to call a gsr engineer

 

[jtsplumbing]

If valves under boiler have been turned off then water to heating will -not get away from boiler thats why it shuts off when you turn on heating, Did you reconnect wires to 3 port valve ?? You could also have a faulty PCB !!

 

[PlumbBobBob]

could be many issues really. you need to find a reliable gas engineer to sort this for you, you shouldn't really be touching the internals yourself.