Boiler leaking from the heat exchanger, fixable?

aftonandpaul

Hi all,

Preface this by saying I'm not plumbing expert, wonder if I could get any advice from any experts out there.

Had a long term problem with our heating system, the pressure (as measured by the pressure gauge on the boiler) was slowly dropping over several months to the point that the boiler would shut off with a low pressure error. This would be rectified by adding water using a filling loop and all would be fine for a few months. I presumed a stubborn leaky radiator joint in the kitchen was to blame and would get around to fixing it eventually.

However recently the boiler stopped working with error E133 (failure to ignite). Also at this time noticed a small quantity of water leaking from the boiler and traced it to behind a large panel covering the ?heat exchanger. In his enclosure there was a large pool of water, in which the ignition system wire connector was sitting. This must have been shorting the ignition - I've dried that connector tied that cable up out of the way and cleared the water. After this, the boiler fires up and heating and hot water taps are restored........

....however I traced the source of the water to the left hand side of the heat exchanger. Its seems to be coming from a seal between the front plate and the main body of the exchanger (I have photos to demonstrate this is detail if this would help the diagnosis). Its dripping relatively slowly but steadily, and seems to drip quicker when the boiler cools down after being off for a while.

What I most want to know is, in your experience, can this kind of leak be fixed? I'm hoping its just some kind of gasket problem (no idea if that's realistic though), really hoping not to have to pay for a new exchanger The boiler was installed 2010 (prior to us moving in) but the heat exchanger was replaced as part of the house sale agreement, so its only 18 months old.

What do you think? Can I hope for good news here? Please advise if you can - and please request more info if I havent provided enough!

Thanks

Alex1983

Where are the pictures? By the fault code I’m guessing it a baxi or Potterton, what model is it? If it’s the boiler I think it is then the heat exchangers for them aren’t cheap, you’d be best getting the manufacturer or BG out to do a fixed price repair.

aftonandpaul

HI thanks for your reply Alex,

Yes its a Potterton Gold HE24

Wont let me add links to photos directly (since I'm a new user) try pasting these in your browser

tinypic.com/r/22drpw/9

tinypic.com/r/11bm6i1/9



Thanks

Alex1983

If it’s definitely not coming from above the bracket then the heat exchanger needs replacing. I would guess it’s at least a £300 heat exchanger, I would look at a fixed price repair, not sure baxi do one or not.

aftonandpaul

Ok not the news I was hoping for but I see you are a credible source of info.

The leak is definitely coming from under the clamp with the two black screws holding the heat exchanger. Presumably there's a leak/crack under there allowing water to escape from the cavity where it is heated.

So do you think 300 for parts and labour or is that only for parts? I'm looking into fixed price repairs and they come out to approx 150-300, does that sound about right?

Oh my poor bank account...

southcoastrgi

Why was the hex replaced in the first place ?
It is very unusual for one of those hex to only last that long unless there is something drastically wrong with your system

aftonandpaul

Hi South,

The previous owners claimed it was done after we requested a gas safety check, perhaps they were telling porkies...

Anyway, I had a look under the clamp and found the leak, coming from the plastic housing on the left side of the heat exchanger, seems to be coming from a seam between two halves of the plastic moulding. I'll upload a photo tomorrow for information.

Alex1983

I agree with southcoast, I’ve never seen one go there, do you have the receipt from when it was last changed it may have a warranty, I’d complain to the manufacturer first and if no joy get a fixed price repair, the £300 will be just the part, I’m only guess at that price though, ring a couple of plumbing merchants and ask for the price of it.

aftonandpaul

Ok first off, here's a pic of the leak location, the small gap in the black plastic, and you can just about see some deep red residue inside, this is where the water emerges.

tinypic.com/r/vn1kqw/9

More worryingly the consensus is that there is something bigger wrong here underlying this, causing the fault.

What could it be? Could there be a problem with corrosion/sludge in the system causing early failure?

😦

qsk

Baxi does have a fixed price repair of around £300. But before calling them, make sure the water is not coming from the flue. Last time I had water dripping down along the heat exchanger walls of my old Baxi, it turned out to come from the flue. Flue is excluded by fixed-price repairs.

aftonandpaul

Ok time to update this. I was wrong about the location of the leak. It's not coming from under the clamp as I previously thought.

It's actually coming from the connection between the heat exchanger housing and the air valve, at the top left. See the video below (copy and paste link).

youtu.be/parghZsbo3g

Any chance this can be fixed cheaply?