How much water should come from my combi condensate pipe?

[MisterBoy]

If that's where I think it is - at the base of the venturi - then that's the gas pipe. You shouldn't really be in there and would advise you leave it alone (as was suggested earlier) and get a new engineer in to strip it down and find where the problem lies.

Don't worry I'm not touching anything. I'm only going as far as removing the external cover to try and see where the leak is (with it turned off at the mains), and to keep it dry until the plumber can get here. I have no intention of trying to fix it or do anything else myself but it was 1/2 deep in there today so I was mopping up. Trying to get anyone out is a nightmare and the whole thing is going to hell with all that standing water if I don't get in with a sponge!!

It's almost impossible to get a good photo but in terms of position, it's directly behind this big metal lump under the combustion chamber, kind of on the rim if that makes sense.
Why/how on earth could water get in there, it just seems a weird issue?

 

[ianmcd]

Read @gas112 post #10 very common fault on that boiler

 

[kidgreen61]

As above

 

[MisterBoy]

To repeat myself, that's not where the water is coming from (and the condensate pipe was already inspected since that's where he originally thought/hoped the problem was)
I found a manual diagram and marked it since photos are tricky - it's not so far as I can tell from the venturi but the bottom of the combustion box itself, like it's dripping through from inside.

I would love it to be something as simple as a bit of pipe but that wouldn't explain water inside the combustion box, right? I don't know if it was this thread, but previously someone suggested a leak on the primary heat exchanger - the plumber had mentioned this a while ago when we had the fan fail but it is such an expensive thing to replace (best part of £700 looks like) he sounded like he really didn't want to given we plan to do major works on the CH this year and probably replace the boiler. We have persistent CH water quality issues causing failures even after a power-flush and plan to replace older radiators and service all the rest... we just need to get past winter!

 

[gas112]

Don't worry I'm not touching anything. I'm only going as far as removing the external cover to try and see where the leak is (with it turned off at the mains), and to keep it dry until the plumber can get here. I have no intention of trying to fix it or do anything else myself but it was 1/2 deep in there today so I was mopping up. Trying to get anyone out is a nightmare and the whole thing is going to hell with all that standing water if I don't get in with a sponge!!

It's almost impossible to get a good photo but in terms of position, it's directly behind this big metal lump under the combustion chamber, kind of on the rim if that makes sense.
Why/how on earth could water get in there, it just seems a weird issue?

View attachment 295782

The grey pipe at the back will be were your leak is it will be split between the corrugations . that boiler is not far off being totally feked with corrosion

 

[MisterBoy]

The grey pipe at the back will be were your leak is it will be split between the corrugations

No, it isn't. I've shown a photo of the water running down that threaded metal section at the front. I sat and watched it yesterday for a bit and after drying that bit I could see water start to seep into the thread from above - this IS how the water is arriving into the tray, the plastic pipe is totally dry.

I WISH it was a bit of cheap pipe but that has been checked already and isn't the source. It's probably a blessing we are planning to replace the boiler, because like you say this water is ruining everything. The tray seems designed to collect any water and stop it escaping so it sits rusting. If there was a drain on it we'd have seen it dripping sooner and probably have less corrosion.

 

[Johntheo5]

How often are you topping up the system as the boiler pressure must be dropping, however slowly?.

 

[gas112]

seeing as you have already got the boiler stripped stick the heating on with boiler stat at 70 and video any water coming out .

 

[MisterBoy]

So we got a plumber out yesterday and the short version is: it's the primary H/E (a pinhole leak he thinks).

Longer version:

He could see the water seeping down from behind the venturi from the spot I showed above, but removing the cover and burner it wasn't actually wet. He checked the seal (replaced previously) and it was good and the condensate corrugated pipe (fine as expected).

He talked about how the condensate pipe is designed to take any water out but if blocked could lead to water backing up, however there was no sign of dampness at the time and the leak didn't continue start while the system was off. But the moment we turned it back on it started seeping again - within moments so far too soon for any condensate issue.

The water seeping out was quite dirty and we have historically had issues with CH water (originally there was a solid fuel boiler we think) - we've had the plate exchanger and the diverter fail previously to getting the system power-flushed but it's still not great. He said it's unusual for the main exchanger to fail but the prolonged exposure to the dirt has presumably caused a pinhole leak somewhere inside the HE. We can't see the leak but there doesn't seem an obvious other option(?)

(Separately, he saw issues with the pressure vessel - it needed repressurising but hardly any water would come out and trying to pump it up (bike pump?!) it just wouldn't take any air at all. He hadn't seen that issue before and was a bit unsure what could cause it.)

A new HE is ~£700 but he did suggest we could use the Baxi fixed-price repair service. I looked it up and it says "from £369" - 369 to replace the HE and any other failed bits is a great price but I wonder what "from" means. Sounds a bit too good to be true.

Anyway because we know the CH system still has dirt issues the ideal plan is to wait until summer and then properly service the radiators - take them outside and thoroughly flush, replace any which seem too bad (many are ~30 years old we think from the old coke boiler). We had half-planned to replace the boiler anyway with a tanked solution but either way, nobody thinks it's a good idea to put a new boiler on a filthy CH system and the same would go for £700 on a new HE if possibly avoidable. Maybe we can use the fixed-price service from Baxi, maybe we can 'limp home' the current boiler, eking out a few more months.

 

[Madrab]

TBH, I'm not sure what Baxi would say when they open that up and see all that rust etc, they may just say it's not economical to repair and condemn it and still charge you for the visit.

 

[ianmcd]

How often are you topping up the system pressure ? is it every day ?

 

[MisterBoy]

TBH, I'm not sure what Baxi would say when they open that up and see all that rust etc, they may just say it's not economical to repair and condemn it and still charge you for the visit.

This is something I wonder too, they say "if we can't repair it you pay £90 callout charge". It seems they phone you to confirm the appointment so I would be very keen to make sure they understand the issues.

How often are you topping up the system pressure ? is it every day ?

The current situation is the boiler goes off about once a week and when we go up, the pressure is 0 with code E110. It takes 5-10s to repressurise to the top of the green section (1.5ish from memory) so that's how much water we're getting though per week. This is with the boiler running pretty heavily though, it's an old house so the heating is on a lot.

 

[MisterBoy]

Bit of an update, I contacted Baxi and it turns out they offer fixed-price for £369 with a £90 call-out if they cannot repair. They ALSO offer a monthly "repair out of warranty monthly plan" for £30.75 a month, over 12 months (same total cost if you don't renew). Under the plan they come for an initial repair and if they cannot repair, the plan is cancelled and you pay nothing.

So we went for the monthly option because knowing the scope of the repairs, this seemed a good deal and we don't really want to wait until summer re-starting it every few days and wondering if something will fail more seriously.

Chap came out today and seemed unfazed by the state of it. He:

1. replaced the primary heat exchanger, after confirming this was the main problem
2. replaced the expansion vessel which had failed probably due to rusting from the leaking heat exchange
3. replaced the secondary plate exchanger which was sludgy
4. replaced the diverter valve even though it was a non-Baxi 3rd-party part
5. totally stripped the entire boiler and cleaned up surface rust

3 & 4 we weren't even aware of issues (the system was working well in terms of heating & hot water), and I think he may have replaced other parts too. He was here something like 3 hours in total doing a full rebuild and the parts alone would cost something north of £700 for myself or a heating engineer as far as I can see.

Got to say that is pretty amazing and we are covered for additional problems and/or a substantial chunk of cash towards a new boiler should it fail in the next year. Wish we had known about it sooner...

 

[muggles]

Bargain!

 

[vulcancontinental]

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