Baxi Barcelona boiler (15sec firing)

[mjd]

Hi
I have a Baxi Barcelona boiler that is driving me round the bend in that it has an intermittant fault the symptoms are it will fire up for approx 15 sec, shut down for 3-4 min then fire up again for approx 15sec and will keep on doing this untill I either get fed up and shut it off or it runs out of time on the time clock! ( during this period of time the green light is on and the pump -controlled by the time clock/thermostat is running) some times it works fine. It is not locking out as referred to on the other very interesting but very long thread. I have checked as much as I can on the boiler and it all seams to be ok. The last time I called the installer out he told me that it was the system and not the boiler!! the fault happens with both HW and CH
Any thoughts or ideas would be very helpful

Thanks

Mike

 

[ChrisR]

Is it exactly the same on CH as HW? Pump would be under suspicion but the problem would be less on HW.

Hope you're saving for a better boiler!

 

[ollski]

sounds a bit like an air flow problem....check the condition of the venturi pipe and clean out the venturi then see what happens.

 

[mjd]

ChrisR
Yes it is the exactly the same on HW & CH and I changed the pump at the beginning of the year.
Suggestion for a better boiler are?

ollski
When I took the fan out this morning it all looked clean and I could see no obstruction in the flue but I will have another look tomorrow.

Thanks for your thoughts

Mike

 

[kevplumb]

better boiler than a barcelona anything

 

[ChrisR]

Of course you shouldn't be in there but since you are, look at the tubes - small scale , an odd bit of fluff can do it.

"Suggestion for a better boiler are?

"
Well, get one , really.
Which model? Almost anything. You said you'd read through that long thread... I don't think it even mentions the leaks.

 

[mjd]

Thanks for all your replys. Yes ChrisR I accept what you are saying, and I agree that if you do not know what you are doing you should not touch, but I would like to think that I know my limits, and when it's time to call in the experts. Although I do sometimes wonder who is the expert!!
Anyway having put it all back together and trying it, only to find it was still the same I had resigned myself to making that phone call on Monday to call out the firm that had installed the thing in the first place, only for my wife to say later on, that the house feels nice and warm & you didn't tell me you had fixed the boiler!! She's right it's all working fine and I have no idea what i've done and it's still working 24 hrs later. Still I don't need to tell her that do I

Mike

 

[BillIrvine]

Are you sure this is a fault ?
My barcelona does exactly the same until either the timer turns the boiler off or the room/tank thermostat is satisfied.
I think it only started going this when the PCB was replaced, Baxi's explanation was that the boiler only senses the the water temp when the boiler is actually lit, hence it comes on every 3-4 mins.
I could live with it if it wasn't for the noise it makes when starting and I can't find out if new PCB's are any different.

 

[mjd]

Bill
Yes i'm sure it's wrong as it didn't used to do it ( for the first 3 years of use) and if both the Hw & CH want heat then all it does - as the pump is permanently running - is to take the heat out of the HW cylinder and push it round the CH and then neither gets as hot as it could do. Also since it has stopped doing this we get hot water and heating very quickly. When it is in it's 15sec firing mode it could take all day to get enough hot water for a shower if the heating was on as well. I would think that your new PCB is faulty or they have not set the jumpers 1&2 on the new board the same as the old one?

Mike

 

[kevplumb]

hot water cylinder??????

tell me more

 

[ollski]

hot water cylinder??????

tell me more

There are 2 barcelonas...one is a system boiler

 

[kevplumb]

takes foot out of mouth and exits stage left

 

[BillIrvine]

Looking at the manual, if all the TRVs are closed the boiler will cycle like you described. Or if you don't have TRVs, possibly flow switch related, although I would think the dry fire lockout should occur ??

As for my boiler the replacement board doesn't have the jumpers.

 

[kevplumb]

sorry guys went off at a tangent the only couple of the beasts i had any dealings with where combis
crap combis at that

 

[mjd]

I'm back again I thought it was all working ok and it has been all week but now it's back to it's I'll only work in 15 sec bursts. I have no idea why it started to work but it did and it's been perfect. so has anyone any ideas were to start looking again or is it time to call in an heating engineer? If I have to go down the latter route does any one have any recomendations in the Bournemouth area.

Thanks

Mike