. This turned out to be 5 days. I have had a go myself and it seems to be working again. The issue they said is that they were finding it almost impossible to get parts for boilers as all the suppliers were shutting down. We are just crossing everything that the fan keeps working until the weather improves and/or the CV19 crisis is over. We do have an immersion heater, in fact I would not want to be without one, they seem to be far more reliable than boilers.
MM