Potterton Suprima 60HE Corroded Fan Electromagnet

[WSB]

A recently replaced fan for a Potterton Suprima 60HE was working fine for a few weeks but now is shorting out, blowing the fuse.
There is now brown corrosion on the electromagnet part of this new fan.
NB: the old one looked corroded and also gave the same fuse blowing problem and I'm now annoyed that I didn't push the heating engineer to investigate further why that corrosion was there in the first place. I was just grateful to have heat at the time and put the corrosion down to the boiler being 10 years old.
However, now I'm seeing the same corossion on a new (and now also not working) fan, I'm wondering what the problem is.
My suspicion is that condensate or something is dripping back through the cold air inlet on to the fan due to a damaged seal with the inner part of the flue or some form of flue damage.
That's my guess anyway. It's a simple short flue but of course must have some connection from the elbow joint to the short pipe that goes horizontally (but slightly raised) outside.
Is this a common problem or can someone suggest any other possible causes?
Hopefully, the heating engineer will pop round today if he can find a slot in his calendar but in the meantime, I would like to be a bit clued up.
Many thanks in advance.

 

[Agile]

It seems very likely to me that the inner part of the flue is corroded and recycling part of the exhaust gases back into the inlet.

These have a high humidity and may well be rusting the fan.

You could try shining a torch into the terminal and seeing if there is any obvious problem.

Tony

 

[WSB]

That's exactly what I was thinking. Thanks Tony!!! Probably better to replace the whole piping section rather than changing gaskets etc?

 

[Agile]

But any flue work should only be done by a gas registered person.

They may not be available new any more although corrosion is such a problem they may well be!

Edit, just getting something out when I noticed that I even have one in stock.

A quick search indicates they may indeed still be available.

Tony

 

[WSB]

I do have a bloke to do it but getting him available is the issue....
Why did you say the flue may not be available new? Is this not an off the shelf item?

 

[Agile]

Flues are normally a part purchased when a boiler is newly installed. When a boiler model is discontinued the availability of the flue usually discontinues shortly afterwards as there is no significant ongoing demand.

There are many better current boiler designs available now and I would not expect the Suprima HE to still be in current production. I don't think that it's efficiency would meet current expectations.

Tony

 

[WSB]

Spoke to our local central heating supply shop this morning. They can sell the elbow joint, complete with 3 gasket/seals for £50 or each individual gaskets/seals for £4 each. I had a look at where the elbow joins to the boiler and can see corrosion where the outer flue connects. All very suspicious and falls in line with what we suspected.
I'm pretty handy and it all looks really easy to replace. So tempted just to buy the parts and do it myself but not sure what the rules/laws are with regard to this.
I do have the heating engineer booked to come Thursday night but that'll be him having a look, then the exra time on top of that to get the parts and then booking him to come back and do it. All very long and drawn out. In the meantime, my house is cold and my family are moaning.
I could buy the flue parts plus the fan that has as a result been destroyed again and do it all this evening and my family would stop moaning about being cold.
But what are the regs on this and the implications on someone like me just doing this?
After all, I wouldn't be touching the gas supply. Just replacing part of the flue and the fan.
Is this allowed for non-gas safe people?
Ironincally, the last work I had done by a gas safe engineer, there was no evidence to prove this was the case.
Ideas, opinions greatly appreciated.

 

[Agile]

A non gas reg person should not even open the boiler.

You can buy the replacement fan and get him to fit it AND diagnose what the underlying problem really is.

I have to say, based on your description, that he seems not to have been very diligent just replacing the fan.

Tony

 

[WSB]

I agree, thanks Tony!
Got the parts now, ready for the heating engineer visit on Thursday. Another fan and the elbow joint flue.
Noticed though that there are two sealing rubber rings that come with the elbow. Big and small for connecting to the straight part of the flue.
But there was no rubber ring for where the elbow flue joins to the top of the boiler. Is there no gasket usually there or maybe I need to get another part?