Hello all

I have a Glow Worm Ultimate 120FF boiler that serves the central heating in my home. The system is only used for central heating and is only on during the winter months.

Unfortunately, the system packed up the other day. I read the manual and used the fault finding guide to perform a diagnosis. In short I believe the fault to be with the Fan Assembly as there is 240V present at both terminals but it just makes a buzzing noise and doesn’t move. However, when I help the fan along a bit and it starts working again. When it was working it sounds as if the fan is really struggling to keep up. Although this worked, only for a short time, the system failed after say ten minutes and the fan buzzed.

I took the fan assembly out and had a look at the connections and noticed the plastic casing (containing the copper coil) was quite brown in colour, almost as if it had overheated or burned out at some stage. I am beginning to question my diagnosis as the fault finding guide asks “Does the fan Hunt?” Thus implying that I need a new PCB! I would have thought that if the PCB is really dead then it wouldn’t fire up the system at all. All 4 neon lights come on and the system operates as normal, but again the system doesn’t stay on long.
The other bit that I didn’t tell you was the fan assembly was only replaced a few years ago. I telephoned Glowworm and they say it should last at least 5 years. Other than this they were really useless and charged me 60p per minute on they premium rate phone number; for a hotline they really are not all that hot.

How can I otherwise test the fan assembly? Does it sound as if fan is in fact on its way out? I am making the assumption that the fan assembly has ball bearings and these are starting to go.

Any help with this problem would be gratefully appreciated. If you need any more information just ask.

Thanks

Gunter

Gunter, December 2009

I have a glowworm 80 with similar problems,wd40 is ok to release the bearings but I find a small amount of engine oil directly applied to the bearings at both ends of the motor extend the life of the fan.
Isolate electrical and gas supplies before working on boiler fan.

philt, January 2010

Hi Gas for free.

Thanks for your response. Well I have sprayed some WD40 and that seems to have helped a bit. It's now been running for a while but it sounds as if the fan is struggling; it's making a great deal of noise. The good news is the house is nice and warm now, just don't know how much longer this will last though.

Should the fan have failed so soon?

Gunter, December 2009

take the fan out. get an extension lead and connect fittings to the extension lead that will connect to the fan normally spade ends. Clamp the fan in a vice or on a bench and connect your extension lead to the fan and switch on.
ideally blow the fan with compressed air to clean it if it does not run a new fan is required. There is no need to connect the earth to do this test.

gas for free, December 2009