Hi
In case it helps anyone else, I just wanted to post about an unusual issue I had with error code fd showing on my Viessmann Vitodens 100 WB1B 35kW system boiler. After much head scratching it turned out the problem was that our mains voltage was too high (257V at the time) and the boiler electrics didn't like it. Basically as soon as the voltage hits 254V, our boiler shows the fd fault. If I turn on the tumble dryer (for example) that drops the voltage a bit and the error code clears. It took a while to work out what was wrong because the voltage was only high enough to cause the problem in the middle of the night and the boiler was working fine during the day.
We are the first house in line after the local transformer and late at night when electrical load is low, our voltage kept creeping up. I contacted SP Energy and the engineers made adjustments to transformers further up the line and our voltage was reduced to a more sensible level.
I was prompted to write this as our mains supply was at 260V at 2.00 am this morning and I am waiting on them to come out and have another look (this is the 3rd time since 2014).
Anyway, I post this in the hope that it helps someone else who is struggling to work out what might be causing an fd code.
In case it helps anyone else, I just wanted to post about an unusual issue I had with error code fd showing on my Viessmann Vitodens 100 WB1B 35kW system boiler. After much head scratching it turned out the problem was that our mains voltage was too high (257V at the time) and the boiler electrics didn't like it. Basically as soon as the voltage hits 254V, our boiler shows the fd fault. If I turn on the tumble dryer (for example) that drops the voltage a bit and the error code clears. It took a while to work out what was wrong because the voltage was only high enough to cause the problem in the middle of the night and the boiler was working fine during the day.
We are the first house in line after the local transformer and late at night when electrical load is low, our voltage kept creeping up. I contacted SP Energy and the engineers made adjustments to transformers further up the line and our voltage was reduced to a more sensible level.
I was prompted to write this as our mains supply was at 260V at 2.00 am this morning and I am waiting on them to come out and have another look (this is the 3rd time since 2014).
Anyway, I post this in the hope that it helps someone else who is struggling to work out what might be causing an fd code.
