Hi, long time listener first time caller...
Sime Format 100C combi boiler. 5 years old, serviced annually, runs perfectly 99.9% of the time...
...when the outside temperature drops down to near freezing it develops a strange quirk.
With demand from either DHW or CH the boiler fires up and delivers exactly as it should but after anything between 30s and 2 minutes the flame goes out, the fan carries on running and then after about 30 seconds, with no outside intervention, the flame reignites and it delivers again. This cycle repeats over and over again.
No fault LED's lit, the temp and pressure gauge on the front are all within working range.
It has been doing this every winter since it was installed. I've had the original installer back to it a couple of times and he's spoken to Sime's technical help desk who have been none the wiser.
Part of the problem is getting an engineer out when it is actually doing it, it can have the problem at 6am when the CH fires up but by 8am the outside temp has risen enough for it to stop!
Any ideas?
Sime Format 100C combi boiler. 5 years old, serviced annually, runs perfectly 99.9% of the time...
...when the outside temperature drops down to near freezing it develops a strange quirk.
With demand from either DHW or CH the boiler fires up and delivers exactly as it should but after anything between 30s and 2 minutes the flame goes out, the fan carries on running and then after about 30 seconds, with no outside intervention, the flame reignites and it delivers again. This cycle repeats over and over again.
No fault LED's lit, the temp and pressure gauge on the front are all within working range.
It has been doing this every winter since it was installed. I've had the original installer back to it a couple of times and he's spoken to Sime's technical help desk who have been none the wiser.
Part of the problem is getting an engineer out when it is actually doing it, it can have the problem at 6am when the CH fires up but by 8am the outside temp has risen enough for it to stop!
Any ideas?