PROBLEM WITH BAXI SOLO 2 40PF Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[wolfies51]

I HAVE A BAXI SOLO 2 40PF THIS PROBLEM STARTED YESTERDAY WITH NO PREVIOUS SYMPTOMS / ERRORS

APPROX 5- 10 MINS AFTER A SUCCESSFUL START-UP BOTH THE MAIN BURNER AND PILOT FLAMES GO OUT
AT THIS POINT THE FAN IS RUNNING THE PILOT ELECTRODE IS SPARKING AND THE PANEL INDICATORS ARE SHOWING THE FOLLOWING

OVERHEAT----OFF
BOILER ON----ON
FAN ON--------ON
PILOT ON------ON
BURNER ON---OFF

IT WILL REMAIN IN THIS STATE UNTIL I POWER DOWN / RESET AND LEAVE OFF FOR ABOUT 15 MINS BEFORE I CAN RE-START IT, OF WHICH IT SEEMS TO START PERFECTLY WELL.

I WOULD BE HIGHLY GRATEFUL OF ANY ADVICE ON THIS MATTER

THANKS
WOLFIES51

[htg engineer]

It seems like a PCB fault - if the electrode is sparking but the pilot is not lighting then is there gas there, if not the gas valve is closed. Possibly the PCB not opening the gas valve.

I''m guessing at PCB as you say there's continuous ignition at the pilot and the boiler is displaying that the pilot is alight.
So there's 2 faults,
if there was no gas at the pilot it could be a faulty gas valve -
but the pilot LED would not be on.

Hope this helps

[muttley]

[quote="htg engineer"]It seems like a PCB fault - if the electrode is sparking but the pilot is not lighting then is there gas there, if not the gas valve is closed. Possibly the PCB not opening the gas valve.

I''m guessing at PCB as you say there's continuous ignition at the pilot and the boiler is displaying that the pilot is alight.
So there's 2 faults,
if there was no gas at the pilot it could be a faulty gas valve -
but the pilot LED would not be on.

Hope this helps[/quote]


Its more than likely to be the Gas valve,when these breakdown the pilot LED stays on.common fault

[wolfies51]

THANKS FOR THE REPLIES AND I AGREE WITH YOUR DIAGNOSIS AND CAN CONFIRM THAT THE GAS VALVE IS CLOSED AS I PERFORMED ANOTHER TEST.

THIS TIME INSTEAD OF POWERING DOWN/RESETTING DURING THE SPARKING STATE, I LEFT THE SYSTEM SPARKING (fan on- pilot fame off--pilot indicator on) DURNING THIS TIME THERE WAS NO SMELL OF GAS INSIDE OR OUTSIDE (fan outlet) WHEN AFTER APPROX 20-25 MINS THE PILOT & BURNER IGNITED AS NORMAL AND WILL REMAIN SO FOR APPROX 5 -10 MINS BEFORE GOING BACK TO SPARKING MODE LEAVING ME WITH CONTINUAL WARM RADS DUE TO BREAKS IN BURNER ON TIME. DOES THIS TIE IN WITH A PCB FAULT OR COULD IT BE A THERMO RELATED PROBLEM.

WITH THANKS

WOLFIES51













I

[htg engineer]

The flame sensing electrode is connected to the PCB, the PCB is detecting a flame at the pilot which is not there - which is wrong.

The flame sensing electrode has to detect a flame at the pilot for the PCB to open the gas valve for main flame.

Check if there's power to the gas valve. If there's no power, it's the PCB at fault.

If there's power there - new gas valve.

[muttley]

Theres power to the gas valve thats why the boiler operates for about 10 mins,then shuts down.LED stays on which indicates the pilot solenoid is the problem.You cant buy just the pilot solenoid,you have to have a new gas valve.

[ALDA]

WOULD IT NOT BE ADVISABLE TO HAVE GAS SUPPLY PRESSURE TO BOILER CHECKED AT GAS METER TO ESTABLISH WHETHER THE PRESSURE IS CONSISTANT AND WITHIN BOILER OPERATION LIMITS BEFORE BUYING AND CHANGING GAS VALVE?.

[wolfies51]

HI, THANKS FOR YOUR RESPONSES -CERTAINLY NARROWED DOWN THE PROBLEM I HAVE SOME MORE INFO

I ACQUIRED A MULTI METER AND MEASURED THE FEEDS AT THE GAS VALVE THOUGH NOT BEING SURE WHICH IS THE PILOT COIL AND WHICH IS THE MAIN VALVE.I HAVE ALSO OBSERVED ANOTHER SPARODIC STATE WHICH COULD PROVE INTERESTING.
THERFORE I NOW HAVE 3 SITUATIONS WHICH I HAVE METER TESTED THESE ARE.(i am going to say coil 1 and coil 2 but will give colours)

WHEN WORKING NORMAL -----COIL 1(left hand of valve when fitted blue wire & orange wire)
ORANGE WIRE GIVES 230VAC
COIL 2(right hand of valve blue wire, earth wire, and red wire)
RED WIRE GIVES 230 VAC

WHEN SPARKING
COIL 1 ORANGE GIVES 230 VAC
COIL2 RED GIVES 0V VAC

NEW STATE (NOT SPARKING & FAN OFF)
FAN OFF-LED OFF. NO SPARK BUT **STILL PILOT ON-LED ON**
COIL 1 ORANGE WIRE GIVES 58VAC
COIL2 RED WIRE GIVES 0V VAC

THANKS AGAIN

WOLFIES51

[jasonmoss]

Wolfie.... What was the fix in the end?? I get problem 3 with
Boiler ON = Lit
Fan ON = OFF
Pilot ON = Lit

And measure voltages at pressure valve at 58V the same as you did.

What was the problem in the end???

[jasonmoss]

[quote="jasonmoss"]Wolfie.... What was the fix in the end?? I get problem 3 with
Boiler ON = Lit
Fan ON = OFF
Pilot ON = Lit

And measure voltages at pressure valve at 58V the same as you did.

What was the problem in the end???[/quote]

I worked it out in the end with the help of Baxi. It was the Gas Valve Solenoid (the one on the left with 2 wires). If you buzz out the left hand wire pair it should be 1.5kohm, and the left hand blue and red should read 5kohm across the terminals. Do this with all the cables disconnected from the valve !! On mine, the left hand solenoid was o/c. Only £70 to replace and it is a very simple task. I didn't need my PCB in the end and just kept the recon one that was only £30 !!