Myson Apollo Shuts Down

[po0041]

My Myson Apollo 30/50 which is about 15 years old shuts down after 10-15 mins and the pilot light goes out.
The thermocoupling has been changed. I can get the pilot light to stay on and fire up the boiler but it only stays on for 10 mins.

Any ideas? The thermocoupling on this model has an 'interupter'. Could there be something else faulty with the safety mechanism?

 

[chrishutt]

If the pilot light goes out it's probably the overheat stat (interrupter) cutting out, due to overheating caused by poor circulation - check pump, sludge in system, air lock, etc. Is there a by-pass valve and do you have TRVs? Does it shut down doing heating or hot water or both?

 

[po0041]

Thanks for the prompt reply.

Pump seems ok. Gets warm but not too hot.
There is a by-pass valve and there are TRV's in the bedrooms.
All radiator's warm up as usual.
The system shuts down for both water and heating.

i'm minded towards a faulty overheat stat.

What do you think?

 

[chrishutt]

It's either a faulty overheat stat or it's overheating. You need to check the flow temperatures to know - I don't suppose you have the equipment for that. My money would be on overheating.

I would suspect the pump since the problem occurs on both CH and HW. One way to check pump is to open the spindle end cover and press your finger against the rotating spindle end. If you can easily slow it down it may be weak. You could just fit a new pump (£40ish) to see if it solves the problem.

 

[po0041]

Thanks very much for your good advice.

 

[joserulz73]

do you hear the boiler spark?

 

[Ian Denny]

Check the flue, it could have collapsed and the air intake could be blowing the gases back onto the burner and blowing it out. It would be intermittent as it depends which way the wind it blowing

 

[heatingman]

check to see if pump is still running just after the pilot has gone out.

 

[mikeddavies]

The 30/50 has 2 temperature stats (high and Low) as well as the overheat stat - try changing to the "other" temp stat i.e from low to high or vice/versa, by the control panel switch, to check for a faulty temperature stat.
MikeD