Don't you just love intermittent faults?

[Dannypipe]

Got called yesterday, then customer called back and said don't worry the boilers working again.

(Transpired he had taken it apart and cleaned the flame rec probe the numpty).

Then I get called today, the boilers done it again.

I get there and the boilers working totally fine.

It’s a Main Combi 24 HE.

It's running fine for me, but customer says it goes to "Burner Failure" sometimes when running water.

I checked amongst other things,
the gas inlet and burner pressures (max/min)
The condensate trap and pipe work.
The micro amps on the flame rec probe (5 micro amps)
The thermistor was about 9K
Both inlet filters on the cold main
The fan's coil (310 ohms).
The diverter and pump proving microswitch.

I didn't check the venturi, and I have a suspicion that there may be a blockage in the plate HEX as there was a rattly sound as hot water was drawn off.

Really weird one though. It worked fine for me, I ran the hot tap for about 10 mins solid and no issue..

Anyone got anything to add to this list. I'm going to pop back tomorrow and take another look.

Hard to repair a working boiler!

Having a bit of a frustrating time with combi's this last few days. This is the second one that's left me scratching the head. Not good.

 

[Leo21]

The white round ones a pig to fit. It catches on the fan, and the looms barely long enough.

 

[Dannypipe]

Oh brilliant!! Looking forward to that then.

 

[Billy Bob Bob]

The white round ones a pig to fit. It catches on the fan, and the looms barely long enough.

you have to aim the tubing ports towards the fan,chuck the tubing behind it,not had a issue with the loom TBH

 

[Leo21]

Are you using the vertical or horizontal one?

 

[Billy Bob Bob]

Are you using the vertical or horizontal one?

cant see the difference aps is in the same place

 

[Leo21]

The ones I get supplied from curzons are vertical with an adaptor securing clip. In the instructions it specifies if its for vertical or horizontal application. There's no clip supplied with the horizontal one. On vertical one the connections foul the plastic cooling fan on the top of the fan spindle. The ones on euro parts are the original Honeywell ones.

 

[Leo21]

Oh brilliant!! Looking forward to that then.

Let us know how you get on, and take some pics when you've got it in. I'm missing something when I fit them. I find them a right cow.

 

[Dannypipe]

Will do. Thanks to everyone.

 

[Dannypipe]

Fitted the APS today. I have taken photos and will upload later. Just this minute got home and thought I'd check my emails while I had a bowl of soup. Which inevitably means I then go on here after!

The APS I was supplied wasn't a Honeywell. The instructions were god awful. After about five minutes of head scratching I figured out how the thing clips in place.

I found that the wiring was very tight, infact I had to cut the cable tie securing the fan and APS wires and then pull some slack just to make the leads fit.

As for it touching the fan, no it didn't, it's close (I guess about 15mm) away, but secure and not touching it.

I'll try to get on later to upload the photos. The APS did have a fault on it, but not one that should have been effecting the boiler. Will explain later, basically it's a 3 wire APS and the boiler uses two of the circuits. The one playing up wasn't the one wired. Hope that makes sense.

Got to go now. Soups getting cold.

 

[Leo21]

It's not just me then, I have to do the same to the wiring loom.

 

[buckley plumb]

the problem i have is when fitting the wiring i keep pushing it off the clip - quite easy with the side panel off though

 

[Dannypipe]

Yeah I took the side panel off. No way I could do it without. I'll get the pics loaded up now.

 

[buckley plumb]

Yeah I took the side panel off. No way I could do it without. I'll get the pics loaded up now.

as mark will tell you if you ever do a diverter remove the pcb - it caught me out covered drop down panel with 2 tea cloths and then wrapped in a plastic bag and taped up and the pcb still got wet and blew - the water tracts down the cables into the pcb.

 

[Dannypipe]

Well I promised you photo's so here you go!!

 

[Billy Bob Bob]

as mark will tell you if you ever do a diverter remove the pcb - it caught me out covered drop down panel with 2 tea cloths and then wrapped in a plastic bag and taped up and the pcb still got wet and blew - the water tracts down the cables into the pcb.

agree 100%

 

[Billy Bob Bob]

View attachment 11447View attachment 11448View attachment 11449View attachment 11450View attachment 11451View attachment 11452

Well I promised you photo's so here you go!!

easy to do LOL done so many can do them blindfolded,problem fixed now?

 

[Leo21]

That's a mains boiler, the baxi,s have two sensing tubes and three aps wires. A tip if your stuck for room at the side to take panel off, take the fan out.

 

[Billy Bob Bob]

That's a mains boiler, the baxi,s have two sensing tubes and three aps wires. A tip if your stuck for room at the side to take panel off, take the fan out.

2 tubes on all variants 24kw has 2 wires 30 has 3 wires be it baxi,potterton or main

 

[Leo21]

There's only one tube Going into the Venturi, where does the other one go?

 

[Dannypipe]

I would have taken the fan out if I'd had to, luckilly with the side panel off it was very straight forward.

Whether the problem is fixed, we shall have to wait and see. Boiler was working when I arrived, and had been ok that day.

I tested the old APS.

The C to NC wasn't working when I blew into it, or it may have been the C to NO wasn't breaking. Anyway it had an issue, but not one that I can see would have affected the boiler, as it was the wrong terminal (if that makes sense!!!!)

 

[Billy Bob Bob]

I would have taken the fan out if I'd had to, luckilly with the side panel off it was very straight forward.

Whether the problem is fixed, we shall have to wait and see. Boiler was working when I arrived, and had been ok that day.

I tested the old APS.

The C to NC wasn't working when I blew into it, or it may have been the C to NO wasn't breaking. Anyway it had an issue, but not one that I can see would have affected the boiler, as it was the wrong terminal (if that makes sense!!!!)

basically the honeywell aps gets too hot behind the fan after it was relocated when the boilers became HE the diaphragm in the switch gets overheated and eventually sticks and fails

 

[Dannypipe]

I wish my memory wasn't so bad, but I installed it, checked it. Then had to dash as one of my best mates called. He had put a breaker though a water mains in his house, and then sheared the stopcock.

Luckilly I was only ten minutes away.

The green centre of the APS did look a little heat damaged, and like I say either the NO wasnt breaking or the NC wasn't making I can't remember so it def' had an issue.

Thanks for all the help everyone. Hope this may help someone else who's called to fix a boiler that works perfectly every time you turn up!!!

 

[Billy Bob Bob]

There's only one tube Going into the Venturi, where does the other one go?

out the back of the combustion box,the airflow through the aps has to go somewhere but its plugged so just a small amount travels down the tube

 

[Leo21]

out the back of the combustion box,the airflow through the aps has to go somewhere but its plugged so just a small amount travels down the tube

If you ever get to go on mastermind, you should choose baxi products as your specialist subject. I'd put money on you.

 

[Dannypipe]

I know, he's brilliant!

Love it. I need to download your knowledge into my brain, along with a good many other brilliant people on here. Not you Croppie.

 

[Billy Bob Bob]

I know, he's brilliant!

Love it. I need to download your knowledge into my brain, along with a good many other brilliant people on here. Not you Croppie.

but i would ring croppie for advice if stuck,knows his stuff,just looks like fester

 

[Leo21]

but i would ring croppie for advice if stuck,knows his stuff,just looks like fester

Youll give him ideas.

 

[Dannypipe]

I'm only playing. I know that man has forgotten more than I know.

I'm just looking for a rise out of him.

Did you know? He's commercial.

 

[wazzer]

Thank you for posting the end result

 

[buckley plumb]

easy to do LOL done so many can do them blindfolded,problem fixed now?

thats whwere i struggled i tried to screw the new plstic clip through the top of the boiler and when holding the aps it kept coming of the clip never thought of fitting it to the old brkt.did you do it without moving things out of the way