Central Heating Issue

[Lynky]

Hello, I am new to this site and I know I should really try to help someone else first but I really do have a headscratcher!

My fathers boiler has stopped firing (it is a Glowworm micron 50ff)

I have checked the airswitch, this is ok.

I have checked the clear and red air pipes, these are ok.

The fan runs when heat is called for but will not operate the air switch.

I have come to a conclusion that the fan is not pushing out enough air pressure to hold the air pressure switch closed.

When I over ride the air switch by sucking on the clear pipe then the boiler fires so I hopefully have eliminated the PCB, the air switch and the air pipes.

What I would like to know is if anyone has come across this before and whether a new fan would fix it?

Also, opinions as to whether anyone agrees with my diagnosis.

Many thanks to all who will take the time to answer this.

Cheers

Lynky

 

[Andy™]

sounds like either the fan or pressure switch

 

[SLIPSHOD & SLAPDASH]

I had similar on my Vokera boiler, the air pipe had a small split. Also could you have a  leak, ie the chamber is not sealing ?

 

[Sidecutter]

I had one like this a few years ago where the nipple that the plastic pipe conects to on the fan housing was blocked. A quick prod with a piece of wire and it was all fixed.

 

[Doc Hudson]

Welcome to the forum, I have deleted your duplicate post in the introduce yourself forum. Duplicates just clutter the forium and make it harder for members to follow the topics.

Doc H.

 

[Lynky]

Thanks all for your replies.

Andy,

I am sure the pressure switch is ok as I can create a vacuum by sucking the clear pipe attached to it and holding the pipe closed after. This allows the boiler to fire. As soon as I release the vacuum, the burner shuts off.

Slipshod,

All pipes are sound. I removed them and blew into them with the end covered, all airtight. Also tried the air switch with the pipes and a multimeter. All operated ok. But put back together, same results.

Sidecutter,

I removed the fan housing and also removed the nipple fitting completely. I then washed it out and ensured all airways were clear before replacing it. Still the same results....

Doc H,

Thanks for removing the duplicate, I was not sure which area to post under.

I have a replacement fan on its way as that seems to be the main culprit.

Will keep you posted - no pun intended.

Thanks again all.

 

[Andy™]

Andy,

I am sure the pressure switch is ok as I can create a vacuum by sucking the clear pipe attached to it and holding the pipe closed after. This allows the boiler to fire. As soon as I release the vacuum, the burner shuts off.

yes, but is it operating at the correct pressure?

 

[Lynky]

Oh,

now you have me. I suppose I will need to get someone with a pressure tester to check it out?

 

[OnOff]

II presume you have the manual? This may assist:

http://www.glow-worm.co.uk/stepone/data/downloads_sd/8c/00/00/micron-50ff.pdf

 

[benji]

flue blocked?

 

[Lynky]

Hi all,

Sorry it's been a few days, I have been in hospital having cruciate ligament reconstruction.

Anyway, the engineer replaced the fan, same problem. Turns out it was the APS. Although operating by override, it was not operating at the correct pressure. Well done Andy, great diagnosis. Luckily the engineer only charged for the switch and kept the fan as a replacement for future use.

Many thanks to all of you who answered. I will visit the site often to see if I can help others (I am an electrician by trade)

Cheers

Lynky