Baxi 100 He plus

[Kev the gas]

I replaced a pcb assy on this boiler about 5/6 weeks ago.

The customer has now complained she has a loud banging / sometimes blowing the pilot out!! (locking out) when using the hot water.

From memory the electrodes and leads are crap on these any other suggestions? combustion box case seal?

Going back in morning, of course it is something I have done or must be covered by the pcb warranty says the customer.

Kev.

 

[Billy Bob Bob]

combustion box case seal and the burners can fail not a good boiler IMHO also check fga settings

 

[Barry98]

id go for fga first , mix will be wrong

 

[arran197]

Sorry to bring an old thread back up, but I have been to look at a 100 he plus combi today a service engineer has turned off due to high ratio. I started by looking at the burner door seals which although have started to go off are all in tacked. I was just about to do a combustion analysis, but as I ran the tap, the fuse in the spur blew. I changed it and it blew straight away again. Found water on the PCB. So the PCB is now knackered. Suspect the flow switch to be leaking as there are limescale marks down the side. So I couldn't continue looking at the boiler, but I have ordered a gas valve for the ratio issue. There not adjustable like the more modern zero valves, so I'm assuming it's knakered. Flue looked ok, but will have a further look when I go back. Other than IWP and MWP, is there anything else that can cause this? Burner looked ok and there are no signs of any melting. The tenant reports an ignition lock out too, but not overheat.

Any help appreciated.

 

[arran197]

Anyone?

 

[Billy Bob Bob]

Anyone?

so you have potentially a gas valve shot a PCB shot,new doorseals and a flow switch leaking not economical to repair IMHO

 

[aggis]

Doesn't sound too good, have had the seal that goes around the burner edges fall apart & throw the ratio's out. I'd always replace the inner combustion chamber seals [red seals] when opening it up.
I agree with gas man, could be expensive.
Just a thought, if the gas valve is fixed [no adjustments] & the gas rate is ok, you might be looking at the burner/H exch or flue.....

 

[arran197]

It's been a week and I haven't been sent back out to repair it. A colleague said he heard my manager and supervisor talking about the job in the office, so not sure what has happened with it. I know the tenant was crying when I said it wasn't going to be working for a while and started swearing lots too. So she's probably got on the phone to the housing association and had her way with them. She was already complaining to me that her neighbour had had a new boiler.

I ordered a door seal, pcb, gas valve, some screws, a flow switch, some flue clips (for in the loft) and some washers for the above. So in all honesty, we're looking at about 3 hours labour (including flue clips) and several hundred pounds worth of parts. I'm guessing trade price on a pcb will be £150 and the gas valve will be around £80. It would be more economical to fit a new Duo Tec in, but the housing association doesn't pay for repair, only replacement, so chances are it might have been repaired already by my supervisor with out my knowledge.

 

[arran197]

I spoke too soon. Got the parts to go and fit this afternoon. Not looking forward to being confronted by the tenant after a week with no ch or dhw. I hope the bits I've got solve the problem because I'm going to be screwed!

 

[arran197]

So I went back to this job yesterday afternoon, fitted all the parts to it and fired it up for a test run. Was kicking out some seriously filthy POCs. So I took the vertical flue apart in the loft. I needed to fit a clip to it anyway, so I pulled it apart. All seemed to be ok until I got to the very first flue section where I found the seal on the air intake side was not correctly fitted and was misshaped. I looked further and what I found was shocking. On the flue outlet adaptor from the top of the flue outlet, the blue rubber seal had completely disintegrated. Rather than being 70mm in diameter, all that was left was a blue powder and about an inch and a half. It was clear to see this was where the problem was when I pulled the flue length out, there was marks on the outside of the flue and surface corrosion on the inside of the air intake (where condense had been present).

This is seriously bad, how a seal can literally crumble in to a powder after 6 years is shocking. The door seal was the same in places, just a crumbly mess. Absolutely terrible design, the boiler obviously gets WAY too hot for it's components to cope with. I was going to get a picture, but I left the small remaining section of seal in the loft and the rest was just dust!

So for anyone working on these bits of tat, check the seals everywhere, especially if you have any dodgy readings or anything that doesn't look or sound right. You could tell something was wrong just by looking through the sight glass, the flames were lifting badly.

 

[ambrosia]

oh man thats my nightmare, you put a whole load of new expensive parts in only to discover its something else. what did you say


It could be difficult getting a new flue for a boiler that old, sounds like a new boiler after all

would have been interested to see the photos

 

[arran197]

Well the door seal, flow switch & PCB all needed fitting anyway. I had to go & pick up a new flue section for the seal, but not sure how much it cost.

 

[arran197]

Just to update this a little. Went to another 100 HE plus that had been put back by a service engineer as high co. Found the flue outlet seal had completely gone again. So ordered one, fitted it and I fired up the boiler. Then the burner ceramic lifted. Had to turn the boiler back off and order the burner. Bloody pain.

 

[Billy Bob Bob]

Just to update this a little. Went to another 100 HE plus that had been put back by a service engineer as high co. Found the flue outlet seal had completely gone again. So ordered one, fitted it and I fired up the boiler. Then the burner ceramic lifted. Had to turn the boiler back off and order the burner. Bloody pain.

wont fit them or work on them they are crap IMHO