Glowworm 50FF - overheat cut off problem

[kevsterdiy]

Hi, im new here but i hope someone can lend some advice.

I have lived in my house for 6months now and have had little trouble with the boiler.

Now i keep having to press the reset button because it keeps tripping out on what i assume is overheat. It keeps doing this randomly, may last a week then another day trip out every half hour! before tripping out everything is normal.

I was told this is probably due to a doggy thermocouple - have had a look in the boiler today and it doesn't seem to be this. (i was told that a thermocouple would detect the heat change from cold to spark/ignition of the pilot light and cut off if there was not a rise in temp - ie pilot light not lit don't open main gas inlet). I could not see this obviously.

It does seem very dirty inside, not black with dirt or soot but a lot of flaky bits, mostly that have fallen from the heat exchanger.

I have now found this .PDF format instructions from glowworm: http://www.glow-worm.co.uk/manuals/pdf/Boilers/Ultimate50FF.pdf
on this i can see no mention of a thermocouple but searching online you can buy spares of them, which look like the thermostat control and thermostat cut off sensor/thermometers!? (page 39/40 of the .pdf) are these the same as thermocouples?

Could this be the problem or could it be something else.
How does the boiler know when to open the main gas valve after lighting the pilot?

Any advice would be good i will clean out the bits and see if that helps for now.

Kevin.

 

[kevsterdiy]

Have now cleaned it all out and it tripped out after two days, still going ok (touch wood) any ideas please. I know i'm new but help would be great full

 

[kevplumb]

leave the pigging thing alone and get it serviced (involves putting your short arms in deep pockets BTW)

 

[kevsterdiy]

leave the pigging thing alone and get it serviced (involves putting your short arms in deep pockets BTW)

None taken!
That is the easiest method yes indeed, although it was only done 6months ago? If there is no simple things i can try or test then i will get a pro on it.

My fathers had his serviced before and watched then and all they did was less than i have so far, clean out the dust at most. (not that i taring all with the same brush) The instructions indicate a service would be quite lengthy and precise which would of course be worth while.

 

[kevsterdiy]

Hi. Update really from some tie ago. - I was right that the boiler was wired incorrectly. I had it serviced and not even the service guy spotted the mistake and was amazed that the last service guy from that same company didn't die! It was a death trap!!!

With the help of an electrician and self teaching myself i rewired the whole heating system. Meant taking up the floor and running 3 new cables but runs as sweet as a nut. Job done.

As for servicing I helped him and there was nothing wring it the boiler it's self.
The service guy even offered me a job, and said you'd make a good sparky.

 

[LittleEagle]

Hi Kevsterdiy,

I have got the same problem and justv raised the query yesterday in the forums. Re-Wiring thats seems to be a big task for a man like me with poor DIY skills !

 

[kevsterdiy]

Hi Kevsterdiy,

I have got the same problem and justv raised the query yesterday in the forums. Re-Wiring thats seems to be a big task for a man like me with poor DIY skills !

Hi LittleEagle

It was quite a task, went about getting all the wiring diagrams and working out how each item should be wired. Especially with about 3 different makes throughout which vary.
Whoever wired it used the earth wire as the live which can catch some out - i hear this isn't uncommon for plumbers to do. As i say mine was a death trap with two power sources on the same circuit!

If your not confident enough it's best to get someone who is. Before i changed anything i ran it by two sparks one who happens to be an ex-boiler man!

Without getting too technical there was a short cut recommended which was to fit a timer to run the pump for a set amount of time after the heating call goes off, effectively mimicking what the boiler does to stop heat build up and avoiding it tripping out.

I went the whole hog and did it completely 'right'.
Sorry i can't be of much more help other than help you prove what the fault is.

 

[LittleEagle]

Thanks a lot for your advice. Looks like I will take a professional help over this issue
regards