I've got a problem with the Baxi boiler in my home.
I've been unable to get to the bottom of the problem after
a run through the fault finding guide in the booklet and also done some
limited testing with a circuit tester to make sure that resistance etc
occurs in the places that it suggests it should.
This has brought me to a dead end and i'm quite happy to admit i'm getting
out of my depth.

So on to the point -

The boiler will start up as normal and run for around 5 minutes - the
radiators get nice a toasty, etc.
After 5 minutes the burner will cut out and the gas flow is cut off (a quick
observation of the gas meter numbers shows this to be the case).

Since the overheat light isn't coming on and all the radiators get nice and
warm that seems to rule the pump out.

After the cutout the fan keeps running and the electronic ignition keeps
trying to reignite the system (to no effect as gas isn't been supplied).
The system then fails to do anything else for the "run time" set on the
timer.
If i choose to turn the system off the "pilot light" stays lit (on as a low
flickering light) until the system is force reset / cools down.

At which point the whole sorry story starts again.

I'm reasonably new to the area i live in and i'm a little bit cautious of
getting a "man in" if i don't have at least a rough idea of what the problem
is likely to be...

I would have spoken to the original fitter but he/she didn't bother to fill
out the installation document (the same applies for everyone on my estate -
i asked).
I'd also like to ask them why the temperature sensor and overheat sensor are
conected to the pipework in the wrong order (but thats another story and
since it's worked reasonably well for a couple of years it doesn't seem to
be the likely culprit(?))

Has anyone seen anything (fault wise) similar to this with this type of
system before and if so could you point me in the right direction as to what
the likely cause of the problem is.

cheers,
-
Richard

In message <(E-Mail Removed)>, Richard
<(E-Mail Removed)> writes
>I've got a problem with the Baxi boiler in my home.

.... ...

>
>After the cutout the fan keeps running and the electronic ignition keeps
>trying to reignite the system (to no effect as gas isn't been supplied).
>The system then fails to do anything else for the "run time" set on the
>timer.
>If i choose to turn the system off the "pilot light" stays lit (on as a low
>flickering light) until the system is force reset / cools down.
>

Do you mean the pilot neon is flickering ?

Is the spark igniting the pilot but continuing to spark and not lighting
the main burner ?

The Solo 3 pcb energises the pilot valve at the same that it generates
the spark

No pilot ----> check to see if there is mains across the pilot valve
solenoid

If the pilot valve is lit, then, if it keeps on sparking, the board is
not sensing the flame

This could be due to the pcb, or the HT lead

I'm discounting other possibilities at this point as they are less
likely and it seems to be either time or temperature dependent

--
geoff

>
> Do you mean the pilot neon is flickering ?

Yes thats what i meant.
I probably didn't explain that very well the first time around.

The boiler on neon will also remain on if something is demanding
service.

> Is the spark igniting the pilot but continuing to spark and not lighting
> the main burner ?

The spark doesn't appear to be igniting anything at all.
Would i expect to see at least some gas usage from the mains supply when
this is occurring? (because i don't)

> The Solo 3 pcb energises the pilot valve at the same that it generates
> the spark
> No pilot ----> check to see if there is mains across the pilot valve
> solenoid

Will do.

> If the pilot valve is lit, then, if it keeps on sparking, the board is
> not sensing the flame

I don't believe the pilot valve is lit.

> This could be due to the pcb, or the HT lead

> I'm discounting other possibilities at this point as they are less
> likely and it seems to be either time or temperature dependent.

Seems likely to me also.

In message <(E-Mail Removed) ernet.com>,
Richard <(E-Mail Removed)> writes
>>
>> Do you mean the pilot neon is flickering ?
>
>Yes thats what i meant.
>I probably didn't explain that very well the first time around.
>
>The boiler on neon will also remain on if something is demanding
>service.
>
>> Is the spark igniting the pilot but continuing to spark and not lighting
>> the main burner ?
>
>The spark doesn't appear to be igniting anything at all.
>Would i expect to see at least some gas usage from the mains supply when
>this is occurring? (because i don't)
>
As I said, the pcb energises the PV solenoid at the same time as the
spark.

Are there volts to the pilot valve when it sparks ?

Yes ----------> faulty valve / solenoid
No------------> pcb fault

It might be worth checking that the PV solenoid isn't open circuit first

--
geoff

> Are there volts to the pilot valve when it sparks ?
>
> Yes ----------> faulty valve / solenoid
> No------------> pcb fault
>
> It might be worth checking that the PV solenoid isn't open circuit first

Turns out it was a fault with the pilot solenoid.
I assume the coil (or something similar) has started to break down.

cheers for the help.

-
Richard

Richard Wrote:
>
> The boiler will start up as normal and run for around 5 minutes
>
> After 5 minutes the burner will cut out and the gas flow is cut off (
> quick
> observation of the gas meter numbers shows this to be the case).
>
> Since the overheat light isn't coming on and all the radiators get nic
> and
> warm that seems to rule the pump out.
>
> After the cutout the fan keeps running and the electronic ignitio
> keeps
> trying to reignite the system (to no effect as gas isn't bee
> supplied).
> The system then fails to do anything else for the "run time" set o
> the
> timer.
> -
> Richard

Hi,

I appear to have the same syptoms as posted by richard on my baxi sol
2 boiler, possibly with a slight difference in that I noticed relay2 o
the pcb shut prior to the burner cutting out. I've changed the pcb bu
to no effect, any suggestions?

Mike

--
MikeB