Hi.
Cheers in advance for any assistance.
Ran into some issues with our boiler last week.
it just refused to switch on any longer.
when the HW/H controller called for the boiler there was a short buzz from the control board and nothing.
The boiler ON light would sometimes flicker very dim for a brief second.
i was pretty sure it was going to be an issue with the control board as i read its fairly common for the control boards to fail.
the board had some discoloration on the bottom around a couple of joints.
I ordered a new control board which arrived today which i fitted.
the board looked just fine was new in box and i have little reason to think it is faulty.
it now has an intermittent fault or i should say it is very intermittently working.
for the most part the boiler light comes on when the HW/H CP calls for it.
but the fan light doesn't come on and the fan doesn't spin up.
If i follow the fault matrix is reads.
Does pump run - Yes
Does fan run - No
Is lock out light on - No
Is fan light on - No
Check control knob is turned - Checked.
i will add that as i turn on the control knob there is a definite click from the Control board as if the board knows it has reached a threshold and should call for the fan to run.
Check wires are connected to thermostat sensor - check connected and tested with MM.
Check the fan and pressure switch plug is connected - checked and also wires test with MM.
Check continuity across sensor - 1m Ohn at 20c - i don't know what is 20c but at room temperature (very cold i might add) it reads around 1600 K Ohm
Check continuity across pilot solenoid - 1.5K Ohm - Checked and is 1.5K Ohm.
what happens once in a blue moon - tested 20 times and once or twice the boiler fires up and everything starts to work except for the burner and burner light will switch off for a second and then back on again.
i suspect the thermostat sensor being adrift but only base that on the higher resistant reading, but that might be due to it being more/less than 20c and 1600k might be within acceptable range.
Cheers in advance for any assistance.
Ran into some issues with our boiler last week.
it just refused to switch on any longer.
when the HW/H controller called for the boiler there was a short buzz from the control board and nothing.
The boiler ON light would sometimes flicker very dim for a brief second.
i was pretty sure it was going to be an issue with the control board as i read its fairly common for the control boards to fail.
the board had some discoloration on the bottom around a couple of joints.
I ordered a new control board which arrived today which i fitted.
the board looked just fine was new in box and i have little reason to think it is faulty.
it now has an intermittent fault or i should say it is very intermittently working.
for the most part the boiler light comes on when the HW/H CP calls for it.
but the fan light doesn't come on and the fan doesn't spin up.
If i follow the fault matrix is reads.
Does pump run - Yes
Does fan run - No
Is lock out light on - No
Is fan light on - No
Check control knob is turned - Checked.
i will add that as i turn on the control knob there is a definite click from the Control board as if the board knows it has reached a threshold and should call for the fan to run.
Check wires are connected to thermostat sensor - check connected and tested with MM.
Check the fan and pressure switch plug is connected - checked and also wires test with MM.
Check continuity across sensor - 1m Ohn at 20c - i don't know what is 20c but at room temperature (very cold i might add) it reads around 1600 K Ohm
Check continuity across pilot solenoid - 1.5K Ohm - Checked and is 1.5K Ohm.
what happens once in a blue moon - tested 20 times and once or twice the boiler fires up and everything starts to work except for the burner and burner light will switch off for a second and then back on again.
i suspect the thermostat sensor being adrift but only base that on the higher resistant reading, but that might be due to it being more/less than 20c and 1600k might be within acceptable range.
