Warmflow Utility 90 HE Combi Leaking and losing pressure...

[gtd65]

Our not so trusty but very efficient Warmflow is currently incontinent!

Over the past 10 years, I've tightened all the fittings, installed new fibre washers ad nauseum, replaced the expansion tank, the flow meter and just this week the PRV.

The boiler is losing water somewhere but looking at all the listed fittings in the manual (and according to Warmflow) they're all on the top side of the boiler, however, in some threads I'm seeing the following information:

"if a combi there is a stupid pipe hidden down the back that has a tendency to leak, and give the impression that its the hex"
Source URL: warmflow boiler - primary heat exchanger of the appliance corroded - https://www.plumbersforums.net/threads/warmflow-boiler-primary-heat-exchanger-of-the-appliance-corroded.68353/

Can anybody shed any light on this?

How do you located and access the pipe hidden down the back?

 

[gtd65]

Well I had my pal round that works on boilers for a living. The leak seems to be somewhere in the crevice between the primary heat exchanger and the heat store?

It's a bloody tricky area of the boiler to see anything at all, so whether it's the heat exchanger or the heat store we've no idea right now. Sealant has been used to see if that helps but so far, it's still incontinent.

 

[ShaunCorbs]

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try this

 

[gtd65]

CT1 Miracle Seal and Corrosive Inhibitor, 250ml: Amazon.co.uk: DIY & Tools

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try this

He did put in some other brand of sealer but looks like it's still weeping out somewhere.

Is that one that particularly effective? Assuming it could be fixed by such a method?

 

[SimonG]

Nothing from the auto air vents?

Have you stripped back the insulation?

 

[ShaunCorbs]

He did put in some other brand of sealer but looks like it's still weeping out somewhere.

Is that one that particularly effective? Assuming it could be fixed by such a method?

It’s very good claims to fix all leaks

 

[gtd65]

Nothing from the auto air vents?

Have you stripped back the insulation?

Here's some photos of the boiler

Three x auto air vents
[automerge]1598390624[/automerge]
Here's the area where the water is collecting
[automerge]1598390802[/automerge]
I don't feel there's any significant leaking from the auto air vents but you can see over time there's definitely been some bleeding.

The crevice between the primary heat exchanger and the heat store is a bugger to get access to for viewing.

I could possibly remove more insulation material to get a better view, are there any "known" areas where these things leak for me to narrow down the removal area?
[automerge]1598391154[/automerge]
I took a snap of the manual page showing the layout of the components
[automerge]1598441530[/automerge]
Well, the floor of the boiler was pretty dry this morning.

Perhaps the leak sealant has made a difference?

After having a further look, it appears that it might be the heat store that's corroded and then the water mists over onto the primary heat exchanger. I took a photo with my endoscope but it's not the best picture.

 

[SimonG]

I was going to say earlier it's probably buggered, but the leak sealer may buy you some time.

 

[gtd65]

Here's what I think is the leak...

[automerge]1598448068[/automerge]

I was going to say earlier it's probably buggered, but the leak sealer may buy you some time.

Yeah it's more than likely just going to delay the inevitable.

 

[SJB060685]

I have known some get replacement stores and replace.

 

[SimonG]

Looked at doing the same for a couple of old worcesters, parts are extortionate.

 

[SJB060685]

Looked at doing the same for a couple of old worcesters, parts are extortionate.

My old man and I were service engineers, not installers. If possible we would always keep a boiler running.

 

[SimonG]

My old man and I were service engineers, not installers. If possible we would always keep a boiler running.

I definitely keep the old worcester heatslaves going. People keep saying they want them replaced, no way.

 

[gtd65]

Been around 36 hours since the leak sealant was introduced to the system and so far things are looking positive.

I'm only using (an indicated) 0.5 Bar of pressure in the system for the time being.

The base of boiler is actually the most dry it's ever been in its life!

I can see a very small reflective, area towards the underside of the rear of the heat store, where I believe there's some sort of leak. It tends to pulse, as if a drip is falling onto it but it looks tiny at possibly less than 1cm diameter. Of course it may well be the corner of a larger puddle but I can't see under the heat store to verify, might try my cheapo endoscope later today.

I agree at the price of replacement parts, some of them are ridiculous for what they are! This is where part numbers rather than manufacturer labelled part sourcing comes into play. I'm fairly sure my flow meter was 10% of the cost of the Warmflow part!

 

[gtd65]

Well, I woke up to a lock out light the other day.

Topped up the water - it was empty and fired it up until the troll that was living inside with a sledgehammer woke up 5 minutes later!

Totally bled and refilled the boiler today and it was up and running for a couple of hours but the pressure was dropping steadily.

Found a definite leak on the primary heat exchanger on the left side of the gap between that and the heat store.

Sealant worked for a couple of months I suppose, probably time for replacement?

Been hearing good things about Navien boilers and the 10 year warranty?

Should I get a new one or any other suggestions?

 

[SJB060685]

Then by the sounds of it its time to replace. I have no personal experience with Navien boilers but have heard great things about them.