Britony Combi 80se - Flashing 40 80 error

[thescrapyard]

Got these error lights about 15 minutes ago as I heard boiler go off, pressure a bit low in middle of red so topped it up using cold filling loop

Boiler goes through start sequence, you can hear fan come on, but then goes into 40 80 flashing lights again

Boiler appears to sound like its not trying to ignite after fan starts, then goes back to 40 80 flashing light error


Water pressure is now slightly above 1 bar and holding, left boiler switched off for 5 minutes but goes back to 40 80 error each time after fan comes on


Suggestions on here seem to be its the air pressure switch at fault, any way of testing this before I go and order a new one later

 

[Agile]

A DIYer should not be opening the combustion chamber or touching the APS.

Someone with the required skills can test the APS electrically at it's connection to the PCB.

Tony

 

[thescrapyard]

I may be a DIYer, but if I can rebuild a motorbike engine and motorbikes, plus work on car engines replacing cam belts and such like, and know how to use a multimeter for electrical fault finding properly I'm not your 'average' DIY lunatic who thinks a big adjustable and hammer are all you need

I do know messing with gas and carbon monoxide can and is a killer, which is something I wouldn't really consider 'having a go'


Thanks for the suggestions though

 

[Terry7556]

scrappy do you have a wiring diagram in the instructions or stuck on the inside of the front cover, not the combustion cover, might be useful

 

[thescrapyard]

I'm assuming the switch is at fault, and no there is helpfully no wiring diagram but I do have a fault/flow chart

Water pressure is fine, but still getting the ever helpful flashing 40/80. All lights work as it cycles through them as it starts the boiler start-up test so I know an LED isn't out and giving misleading fault codes (as suggested elsewhere so I'm not misreading fault codes)


As the air pressure switch may be at fault, the self test won't go any further, so until that turns up and is replaced I'm stuck, just checking the connection to the switch with the multimeter if that comes back OK, then it suggests the switch

You can hear it clicking and sucking/blowing 'gently' on the tubes shows the internals are working, but as with anything else this doesn't actually prove the switch is fine

The pressure switch hasn't been changed that I know of in the past 5 years and the amount of switching it does for hot water/heating will only last so long before getting past it



Off topic ever so slightly, but you get the same annoying problem with starter solenoids. They click but refuse to start the bike/car. Strip them down or change the solenoid and everything is fine. The switch has just got to old and too high resistance to actually pass any current anymore

 

[Terry7556]

you sure its 40 and 80 , not 40 and 60 and 80? 40 and 80 flashing are low water pressure

 

[thescrapyard]

No, positive its 40/80 flashing

Thats what I can't get, the water was low. Topped it up, but still goes to 40/80 flashing after boiler trying to start

The fan is starting, you hear a click which I assume is the air pressure switch then it goes to flashing 40/80 everytime


Read somewhere else that if it still flashes 40/80 after topping up the water pressure then try the air pressure switch as I think that is the next in line for self test. Part on order so will have to see

Not much in the way of sensors, it only has about 5 not including the gas solenoids. Unless its the PCB once again. The last one was changed about 15 months ago to a revised model that cured the last fault straight away which was a PCB fault

 

[thescrapyard]

Is there a pressure switch that may be faulty, so it thinks there is no water pressure when the pressure is fine. Its at 1bar, just above the red with the boiler switched off

Turn the boiler on, the fan starts, you get one click from the air pressure switch, then 40/80 flashing. Thats as far as it gets everytime

The fault reads as low water pressure, but it isn't low. It was low and I topped it up using the cold water filling loop, gradually and not by simply turning the valves on full. Boiler went off on Friday morning as I was off work and heard it switch off. Was working fine until that moment



I'm looking at replacing this junk with a Vaillant EcoTec 24, and already have a rough quote for installation, plumbing in the condensate pipe to a waste pipe, power flush and fitting a magnatech filter for around £850 assuming its straight forward, and will happily give a written quote as our council gives a rebate for having energy efficient boilers fitted. I know that not as cheap as you can get, but he was suggested by the local gas parts suppliers which did say he isn't the cheapest but is known for good work and attitude

I asked for the power flush and magnatech as its been suggested its better to start with a clean system rather than all the old crud running straight into a new boiler, causing more breakdowns and problems in the future

Also looking at possibly fitting a scale reducer, as they are only £25-£30 and just plumb straight in. We are in a low hard water area, being in Lancashire, but we do still suffer from it


The installer is quite happy for me to get the boiler, flue and wireless room kit or he can quote for getting it all, as he claims its still covered by the Vaillant guarantee regardless who buys it all. These package prices seem to be from around £850-£1100 with VAT

He's an approved Vaillant installer, on the council register and has already suggested I look at various places to 'check him out'

 

[Agile]

If your boiler is not showing other faults then its probably on quite a clean system already which does not need power flushing and particularly when a mag filter is fitted.

You should not be changing the APS yourself.

Tony

 

[thescrapyard]

After spending considerable time hunting around, it appears yet another common fault is the water pressure switch failing, giving the impression of low water pressure fault even though there isn't low water pressure

I'll look at that in the morning as that's a 5 minute job which I can easily check


Still looking at that new boiler replacement though, either a Vaillant EcoTec 24 or 28. Reading countless reviews and suggestions the newer revisions are better than they were and the quote for fitting is about right