Help or Advice on Combi 80E Please - Wits End!!!

[gtech2]

Hi,

I have a Baxi Combi 80E which is approx 3yrs old. We have a fault on it in that every now and again the boiler will fail to ignite and you have to go and do the reset thing to start it, it might be okay all day then, or you might have to do that a couple of times during the day.

Seems to happen more when the heating has been on, dropped down in temp and the sensor tells it to turn on to bring the heat back up to the thermostat temp, end up having to do the reset.

When you do the reset it starts first time no problem.

we've had a couple of engineers out, one did the hmmmmm thing and never came back, the other said it was the board, duly replaced the board and it did'nt cure it, so he banged the old board and put it back in, and hey presto for about 6 weeks it was fine, now we have the heating on all the time its back to its old ways.

I'm mechanically and electronically minded and dont mind poking around IF I had a bit of guidance.

Just seems that none of the local engineers want to have a look at this boiler. The company that fitted it have since gone to the wind.

Any help or advise would be welcome.

Thanks

Graeme

 

[Paul Barker]

What you need to know is at what point in it's sequence it fails. So there is a call for heat, what happens, do you hear the fan start? do you feel the pump vibrate? do you here a ticking as the ignition sequence starts?

Secondly that boiler may have a row of red diagnostic lights, if so, the lit one when it is locked out would have a symbol beside it. What does that symbol look like?

 

[Agile]

Whilst the PCBs have not been that reliable it does sound to me as if the problem may be associated with the settings of the gas valve.

Since that should be done by a CORGI registered engineer, I cannot give you any further advice on how to set it.

Tony

 

[gtech2]

Thanks guys for the info, further......


You can hear the boiler going through its startup sequence, hear the fan start, pump vibrates and then you hear the ticking and then nothing, at that point the red light furtherest to the left comes on, which indicates "Flame Failure".

At that point I can turn the knob to reset and the system fires up, can go all day okay then, even through to the next day, but at some point when heat is called for it will fail and when we look its the same red light for "Flame Failure".

Thanks Guys,

Tony - Fully appreciate what you are say....Trouble is, of the 10 engineers I have rung in our area only one would come out, he looked, went away to get parts and we've never seen him again in the last 6 weeks.

Last time I buy a Baxi

 

[ollski]

Has it had a service in those 3 years?

 

[Agile]

Please dont blame the Baxi !

Its not the boiler's fault that the person who fitted it probably did not check the setup of the gas valve. Bang it on the wall and switch on then out of the house. ( And of course as a conscientious engineer I always check that on an installation or a service, I dont want to be called back. )

Its an unfortunate fact that many CORGI registered people dont actually know how to set up gas valves, or as the fellow who "went away to get parts" shows, cannot diagnose faults on boilers.

You could be blamed for not getting it serviced after the first year but even if you did its unlikely they would have checked the gas valve setup.

Tony

 

[gtech2]

Yep serviced.

Tony.....You must know our engineer soooo well, which is probably why we cannot get hold of him now, nowhere to be seen and last seen heading down the A1M on a black charger.........being chased by Wyatt Earp.

So.....whats the best course of action here????

 

[gazthepottertonengineer]

get a corgi registered engineer in and tell him to set the low gas rate at the correct setting easy really especially when you have the right tools i.e digital manometer

 

[Agile]

And while he is there get him to check the positioning of the flame detector probe as well.

Tony

 

[Paul Barker]

Hey Gaz, I have a Kane 400 so could do it that acurately, but don't normally. Is it that critical? I've been using a u guage for most of that type of work because it doesn't take 20 seconds to come on, doesn't make a horrible noise, take another so many seconds to turn off, is lighter and easier to carry, les likely to break, won't cost a fortune to replace if it does break.

To be honest I only ever use it to set up the co co2 ratio where it's ultra fine sensitivity IS required, I don't even wave it in the flues isntead of servicing. I do the service and as long as the casing seal is intact and the flame picture is good I don't wave it about at negative pressure room sealed appliances.

I>E> it stays in the van most of it's life.

 

[Agile]

Standard "U" gauges vary in their ability to be read accurately. I am lucky to be using a white one which can be read to within 0.2 mb. The yellow one is difficult to read to within 1 mB particularly below 2 mB.

I used to use a tiny digi one until a builder stole it from me. I have a larger digi one but dont normally use it. I also have a Kane 400 but also rarely use it on domestic equipment.

Some of the latest premix boilers need a manometer with two places of decimals to set them up! Some meters are more stable than others!

I dont see the baxi/potterton as that critical on minimum gas pressure as long as the flame detector is correctly positioned in the flame.

Tony

 

[corgigazza]

Before adjusting gas rate sometimes the injectors on the burner bar get blocked especially on lpg

 

[gtech2]

Hi Guys,

Well the bloody thing has been on and off like a yo yo, so been watching it to see what is happening, so here is what I have noticed.

1. The YELLOW LED to indicate the PILOT (I presume) on the bottom row, flashes on and off approx every 5 secs when the system is heating....is this normal ????

2. When the unit is heating, watching the flames through the window, I can see that the flames increase in intensity approx every 20 secs for about 5 secs ????

3. When the unit is heating, flames are running, I can hear a ticking coming from the spark generator, it will tick for approx 15 secs, stop for about 4 secs, etc etc ???

Is there any other diagnostics I might be able to try to narrow this damm thing down.

Can you recommend any good engineer covering the North East, in particular Darlington.

Any advice is appreciated.

Thanks guys

 

[Agile]

Sounds as if boiler is not detecting the flame correctly.

Could be min gas pressure, electrode position or continunity or PCB or even more than one.

Tony