Fan not running on Buderus boiler (Err Code 3L)

[uptown47]

Hi there,

I awoke to find that my boiler was flashing an error code (3L) which, according to the manual, is a problem with the fan tacho.

My boiler is a Buderus 500 - 24C.

I followed the fault finding procedure in the manual (checking voltage to the fan board etc) and I found that when I just spun the plastic-fan-bit at the back of the main fan and then started the boiler then the fault cleared.

That was 3 weeks ago and the boiler has run fine until today when the same fault returned.

I just powered the boiler off, manually spun the plastic bit on the back of the fan and then started the boiler back up and it's running again.

The fan isn't making any undue noise although it does feel quite 'weighty' to spin but I'm not sure if that's normal.

I just wondered if any of the experts here have any idea what I can do to permanently fix this issue?

Here's some pictures of the fan and the whole boiler to help you understand what I'm rabbiting on about.

Thanks for any help you can give me.

 

[ianmcd]

that fan works using a series of magnets and sometimes when it stops it is landing on a faulty magnet you need a new fan

 

[uptown47]

Ian,
That sounds exactly like what's happening! As I turn the back of the fan by hand I can feel that it was 'heavy' but that will be the magnets clunking it round as it passes from magnet to magnet.

I don't suppose you know what the fan is called do you and then I can Google it and try and find a replacement?
(I'm also assuming that they are closed units and I can't just replace a faulty magnet?)

Thanks for your excellent reply!

 

[muggles]

You shouldn't be taking the casing off your boiler - it forms the safety room seal that is there for your protection and removing the case breaks this seal

You can fix it by calling a Gas Safe Registered boiler engineer next time it stops, and leaving it in the fault condition so they can carry out diagnostic checks

 

[uptown47]

that fan works using a series of magnets and sometimes when it stops it is landing on a faulty magnet you need a new fan

It's ok I've managed to find the fans for sale on eBay and the like. Will have a look at what is involved in changing it when I get home from work.

The boiler is on it's last legs TBH so we might just end up buying a new boiler and have done with it as I've had to repair it several times over the years and I think it's run it's course. However, I've found a fan for £130 so if it looks like an easy fix I might just sort it.

Thanks again for all your help Ian.

Cheers

 

[uptown47]

You can fix it by calling a Gas Safe Registered boiler engineer next time it stops, and leaving it in the fault condition so they can carry out diagnostic checks

When the fault first happened I did do this. I phoned 2 "Gas Safe engineers". None of them answer so I left messages. Only one of them phoned me back. He said that most gas engineers nowadays don't bother with boilers as they are too much hassle. The other guy didn't even bother to phone me back! Hence I just followed the instructions in the manual myself and sorted it.

 

[ianmcd]

its not something that you should be changing yourself, the combustion has to be measured and adjusted if necessary when the new fan is installed you really need a Registered gas installer to do this

 

[uptown47]

its not something that you should be changing yourself, the combustion has to be measured and adjusted if necessary when the new fan is installed you really need a Registered gas installer to do this

Duly noted Ian. If we don't decide to change the boiler then I'll just source the fan and then contact a company to come and do the change for me. Thanks again for all your help. Really appreciate your expertise on this. Cheers

 

[ianmcd]

He said that most gas engineers nowadays don't bother with boilers as they are too much hassle.

you dodged a bullet there mate, what do gas engineers do then ?

 

[bernardgreen]

You should find a trademark on the fan, if you can trace the manufacturer of the fan then it may be less expensive to buy the fan direct, but be sure you get the exact same fan as the speed control protocol may vary between different fans.

That said ensure it is a qualified person ( GasSafe ) who fits it and then carries out the necessary flue gas analysis testing.

 

[uptown47]

you dodged a bullet there mate, what do gas engineers do then ?

Lol, that's what I thought. I've got a mate who's a joiner and does plenty of new builds etc so I'll speak to him and see if he has anyone he can recommend.

 

[uptown47]

You should find a trademark on the fan, if you can trace the manufacturer of the fan then it may be less expensive to buy the fan direct, but be sure you get the exact same fan as the speed control protocol may vary between different fans.

Thanks for the tip Bernard. Will do

 

[ianmcd]

Where in Scotland are you ?

 

[uptown47]

Where in Scotland are you ?

I'm in Kirkcaldy, in sunny Fife

 

[ianmcd]

a bit too far for me but others will see your post and may be nearer and happy to take the job on for you