Myson Marathon 600C main burners not lighting

[colorado]

My boiler was working fine till yesterday for both water and heating. Now no heating or hot water.
The pilot light is fine, I have switched it off and re-lit it and it stays on fine.
I've checked the electrical supply to the boiler and it is also fine.
When I turn the boiler thermostat knob up to 7 the main burner still does not light.
Room thermostat is set to max, and time controller is on for both water and central heating.
I've also checked the header tank in the loft and it has water in it and the float valve is working.
When I turn the boiler thermostat I can hear a faint click before it gets to 1 on the dial, is that the point at which the main burner should light?
The boiler just has a thermostat knob, no programmer or timer on the boiler itself.

Any help very much appreciated as it's getting chilly.

 

[Agile]

This is a very simple and old boiler.

There is virtually noting in it.

The flue spillage detector could have tripped and you can reset that to make it work.

However it would not normally trip and if that's what has happened then there may be a flue fault which could be dangerous,

I hope there is proper ventilation and no obstruction to the flue?

Tony

 

[colorado]

Thanks agile. I saw this about the flue spillage detector in the manual but I can't see one on my boiler. From the diagram it looks like it's on the underside of the control panel box and I've attached a photo. The mains cable goes in at one side, and the cable to the gas valve comes out the other. As you say nothing else really to this boiler.

Tonight I tried switching off, then waiting a few minutes, re-lighting the pilot, then turning up the thermostat. Just when the thermostat passed the "click", there was a bit of a noise like the boiler was about to fire up the main burners - but then nothing. I got the same noise some of the time if I tried turning the thermostat right down then up again. Does this suggest thermostat or gas valve, or something else?

Boiler

• colorado
• 25 Oct 2013
• 1

underside of control panel box, showing thermostat wire and mains lead

Boiler

• colorado
• 25 Oct 2013
• 1

Myson Marathon 600C data plate

 

[Agile]

Without examining your boiler I can not say if the flue stat is fitted or not but its shown on the manual!

The simple answer is that without measuring voltages I cannot tell what is happening.

But gas valves are a no-no for DIYers.

Sounds to me that you may need to call any friend who is handy with a multimeter or a professional.

Tony

 

[colorado]

Without examining your boiler I can not say if the flue stat is fitted or not but its shown on the manual!

The simple answer is that without measuring voltages I cannot tell what is happening.

But gas valves are a no-no for DIYers.

Sounds to me that you may need to call any friend who is handy with a multimeter or a professional.

Tony

Thanks all who commented. Consulted RGI and in the end bought a Worcester new combi.

 

[Agile]

That's a pity!

It was such a simple boiler to repair!

Tony

 

[gas112]

hope you didnt buy new boiler because you where given wrong advice , as agile said simple fault repair most probably gas valve solenoid part around 40 quid