Ideal Classic FF280 Problem - can you help?

[chrisk1]

Hi,

I have an Ideal Classic Boiler which has been very reliable other than one fan replacement in its life. The Boiler will not currently fire. I hear two relays click but the boiler fails to fire. I initially thought it needed a new fan but checking voltages no power is being received by the fan. At the top right of the boiler (I assume this checks differential pressures there is power). On the motherboard the fuse is OK.

Can anyone suggest what may have gone wrong and what to check? Any advice would be appreciated.

 

[twgas]

Is there an overheat 'stat ? (Little red button to the right of the control box.)

 

[chrisk1]

Is there an overheat 'stat ? (Little red button to the right of the control box.)

Thank you for the reply. Yes there is. I have pressed it, but it has not helped. There is power on both terminals of it.

 

[chrisk1]

I have been working through the fault finding guide. The fan does not start if I remove the stat, as Ideal say it would. They then ask for the supplies to the pressure switch to be checked, looking for power on the violet and red leads - which I have. The fault finding guide then just says check cables. I have done this and all is OK.

What I am unsure of is I thought that the pressure switch would check if the fan is running. Does it have another use as well?

If anyone has any idea what to check next I would appreciate it.

 

[twgas]

how, exactly, are you checking for power on the red and violet leads?

 

[Agile]

This is likely to be a gas/combustion problem and you should not get any advice on that here. We dont recommend that a DIYer opens the combustion chamber.

You should call a competent engineer to diagnose the fault and check that it is safe.

Tony

 

[chrisk1]

I emailed Ideal how provided incorrect advice that it was the air pressure sensor - I have definitely proved this is not the case.

I suspected the PCB and spoke to a company who refurbish PCB's. They say the key failure of the PCB is the fan relay. I have some blackening on one set of contacts so have ordered a replacement.

I will find out for definite tomorrow.

 

[chrisk1]

how, exactly, are you checking for power on the red and violet leads?

With a multimeter with one probe on neutral and one on the coloured cable.

 

[chrisk1]

Thank you for the advice everyone. I will report back tomorrow on whether it is fixed.

 

[chrisk1]

New PCB arrived. When I took the old PCB out it had scorching by the fan relay on the PCB.

Boiler now fully running. Thank you for your assistance.