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Hi all
I have a Vaillant VUW 242 E that suffers from intermittent ignition.
I have checked the following and unfortunately bought and fitted a new control pcb with no success. If anyone can help then I would be very grateful.
I have checked the operation of the air flow switch. Also measured the volt drop at the circuit board when the boiler failed to light.
Cleaned the fan and the flue, also the air flow switch tubes back to the switch.
Checked gap and cleaned the ignition electrode. Ckecked the loom abck to the board.
The system fails to light and the following occurs.
The fan will run and the LED lights on the panel.
The valve LED lights up suggesting the valve opens, air flow sensor is triggered and the gas is flowing. But I do not get the sparking from the ignition.
But what I can tell from when the boiler works (fires up) is that the sparking does not start until what I believe is the boiler knows that gas is flowing to the burner. I now think that the sparking will not start until the boiler knows that the gas valve is open. Does the gas valve position feedback or is there some other feedback to the control showing gas flow that lets the control start the spark ignition??
I have a Vaillant VUW 242 E that suffers from intermittent ignition.
I have checked the following and unfortunately bought and fitted a new control pcb with no success. If anyone can help then I would be very grateful.
I have checked the operation of the air flow switch. Also measured the volt drop at the circuit board when the boiler failed to light.
Cleaned the fan and the flue, also the air flow switch tubes back to the switch.
Checked gap and cleaned the ignition electrode. Ckecked the loom abck to the board.
The system fails to light and the following occurs.
The fan will run and the LED lights on the panel.
The valve LED lights up suggesting the valve opens, air flow sensor is triggered and the gas is flowing. But I do not get the sparking from the ignition.
But what I can tell from when the boiler works (fires up) is that the sparking does not start until what I believe is the boiler knows that gas is flowing to the burner. I now think that the sparking will not start until the boiler knows that the gas valve is open. Does the gas valve position feedback or is there some other feedback to the control showing gas flow that lets the control start the spark ignition??