Vitodens 050 - F4 Fault Code - Only Intermittent

clockworkp

Hi All,

I have a vitodens 050 (viessman) that is fine for about 1 hour sometimes more but always resorts to an F4 fault . I can find lots of info on what can cause this but not at such intervals.

I'm useless when it comes to gas heating so even basic, obvious advice would be appreciated.

Thanks

GGross

That's a European model, though i suspect the fault codes are similar to what I deal with. F4 is a "no flame signal" error code. This could be a faulty flame sensor, bad gas pressure, bad gas valve, bad ignition module. The only really "nuisance" cause of this that does not involve gas or electronics is that the condensate trap (siphon) could be plugged or otherwise not draining correctly. Might be best to call a pro