Water in air intake and fan unit Vaillant Ecotec 837

[tpt200]

Getting fan / flue error symbol and fails to fire. A lot of water was under the boiler (2 litres say). Water inside boiler.

Drips from air intake joint on fan unit, pulled the intake off and loads more water came out.

Managed to get a plastic tube and syphoned about another half a litre out.

First thought was rain coming in through flue vent, we had a LOT of rain yesterday. The inner flue extends beyond the outer, might have been blown off / removed, but no sign of it.

Anyone seen this before or have any idea how to fix it?

I'm getting fault code F.32 -

 

[bell824]

Try looking at your condensate install first!
Is it in a rainwater drain by any chance ? Is the condensate line blocked ?

 

[ScottishGasMan]

+1 for the condensate piped directly into a rain water down pipe (its a no no but very common to see) Heavy Rain and a slow draining downpipe will create a backpressure up the condensate pipe and force rain water up into the boilers heat exchanger and out into the fan+Gas valve, practically the only way water can get into one of these fans.

 

[tpt200]

Yep, looks like you were right. Condensate drain goes into the downpipe from the gutter. Got a heating engineer round this morning, the fan will now need replacing. Can I just put a hole in the side of the condensate drain just before the downpipe in case of back up, to let it flow out?

 

[Agile]

A DIYer should not be opening a more recent Vaillant because the cover forms the combustion chamber cover.

Luckily an engineer has now been.

Putting condensate into a rainwater drain is always risky.

Although not strictly correct a 5 mm hole in the top of an outdoor pipe will give an indication of a problem but with the amount of rainwater coming into a downpipe in a storm might not prevent such a failure again.

Tony

 

[ScottishGasMan]

Page 10 of this document is the minimum you need to do if your going to insist on keeping it terminating into a downpipe. Or else you'll be forking out for a new fan again very soon (and I'll just say now if a fan is all it needs then I'd be very surprised)

http://www.centralheating.co.uk/sys...ATE_DRAINAGE_PIPE_INSTALLATION_Final_2011.pdf

 

[Dan Robinson]

Doesn't the board and Gas valve usually get taken out in this situation too?

What about the insulation on the burner head?

Could be bottom achingly expensive this one

 

[tpt200]

Oh please don't say that. I'd like to have a word with the guy who fitted it for me. I'll dig out a proper soakaway over the weekend before the engineer comes round to fix it.

The board stayed dry luckily, but it's the bits above the fan I'm also worried about.

 

[ScottishGasMan]

Typically Fan+Gas Valve as a minimum, sometimes electrodes, and sometimes PCB if the water got there or one of the above wet components damaged it, but not very common to need to do the PCB aswell. Insualtion is normally ok but would need inspecting to confirm.

Dosent sound like hes came across this often if hes said it will just be the fan. He wouldnt know about the gas valve till the fan was fitted and magically he cant get it to pass emmissions tests. But, theres a small chance if your very very lucky.

 

[gasanstuff]

The last one of these I did all worked ok when dried out, but the one before was gas valve and fan that went.
It is luck of the draw, and obviously linked to how much water got into vital components!

 

[Tipper]

Page 10 of this document is the minimum you need to do if your going to insist on keeping it terminating into a downpipe. Or else you'll be forking out for a new fan again very soon (and I'll just say now if a fan is all it needs then I'd be very surprised)

http://www.centralheating.co.uk/sys...NAGE_PIPE_INSTALLATION_Final_2011.pdf[/QUOTE]

Some diagrams in that doc show clear air-breaks between the boiler's condensate pipe and the internal drain pipework or trap, etc.

Doesn't this mean there is direct route for combustion gases to escape into the interior of the house if the condensate drain is a simple connection off the combustion chamber? (Doesn't apply to boilers with built in traps off course.) Is that really allowed?
Shouldn't there be a trap at the end of the condensate pipe before it discharges into a drain connection?

 

[wannocks]

No, there is already a trap in the boiler. Secondary traps can also cause the condensate line to airlock.