Glow Worm Economy Plus 50 problems

[iansums]

I have had problems with this boiler for about a year on and off. It is nearly 10 years old and for the first 9 years I never had a problem.

About a year ago had a problem with the pilot light going out. My local independent engineer changed the thermocouple but I continued to have problems. If I remember correctly he then changed the overheat thermostat.

All was ok until the summer when I found the hot water was not switching off. This proved to be a sticking motorised valve. I have lived with this problem for a couple of months until this Friday when the engineer came to fix it and also do a service.

Now I appear to be back to the problems of a year ago. Straight after the service the boiler cut out after about an hour. The engineer came back to change the thermocouple. All was ok for a whole day until I found the boiler had cut out again.

The pilot lights first time consistently without any problem but with the heating on the boiler cuts out after about 15 minutes. I also left the pilot light on overnight only to find it had gone out the following morning, no heating or hot water was on during this time. Pilot light was lit again this morning and is still on after 2 1/2 hours.

Bear in mind that for the past couple of months the heating and hot water have been working fine other than the fact that the water was permanently on.

Have asked the engineer to return to look at the problem, but would be interested if anyone out there had any ideas.

 

[Boilerman2]

Check water circulation around the Heating system - sounds like the boiler is overheating and knocking out the pilot on this model the overheat stat resets automatically so when the engineer re-attends it is very difficult to work out what is going on sometimes, but my money is on a circulation fault!!

 

[StevenJames125]

could be some air in system, have known before this knockos out pilot via the overheat interrupter - or the pump could be slow/failing or a dirty system. Try turning pump speed up and see what happens? sometimes if pump is failing/running slow and causing an overheat - turning pump speed up can keep it going for a while longer

 

[iansums]

Thanks for the tips. Engineer came out again yesterday and changed the overheat stat but this has not fixed the problem. Noticed this morning that there is no click on the boiler stat when rotating fully from min to max.

Could it be the boiler stat is faulty?

 

[StevenJames125]

So pilot stays lit now?
Boiler fires up
And after a short while it goes off/pilot goes out?

 

[iansums]

So pilot stays lit now?
Boiler fires up
And after a short while it goes off/pilot goes out?

That's right, takes about 30 mins before it cuts out.

 

[StevenJames125]

it'll probably cut out quicker on HW only as less space/ways the heat can be given off so it'll overheat quicker

Sounds like a boiler stat failure

As you have an overheat interrupter this will be open circuit (on continuity) when the fault happens.

 

[iansums]

Yes, I'm suspecting the boiler stat. Engineer has asked me to do a few checks tonight and he will be back tomorrow.

I'm also wondering about air in the system as I know that he did not bleed all the rads after changing the motorised valve. I will also do this tonight.