I have a 30ish year old Myson Velaire Oil fired boiler locking out. It runs for 5-30 minutes - sometimes even less if I reset it shortly after it locks out, runs for longer end of the scale if I leave it for 30+ minutes. I can hear the fan running for 10-20 second after I hear it stop burning, but before the lockout light comes on. It locks out if I have it set for hot water only or for heating + hot water. Except if the hot water is already hot it does run for 5-10 minutes then switches itself off before it locks out.
It has an Interoil 10 (I think) burner with a Satronic TF701B control box and a Satronic FZ711 photocell.
I've done some investigation and my current suspicion is the photocell, but direct replacements are no longer available. I've cleaned the windows on the photocell, but they weren't particularly dirty.
I've read that the MZ photocell might be OK, and I've also read that if I were to use a MZ then I should use a new control box. Would a new control box simply slot into place where the existing control box is?
I tried changing the jet nozzle yesterday to the 80S one recommended in the manual, but this didn't work as well as the 80EH jet in there already, so I swapped it back and have ordered a new 80EH jet - although I don't believe this to be the problem.
Any thoughts what my best plan of action is?
Thanks
It has an Interoil 10 (I think) burner with a Satronic TF701B control box and a Satronic FZ711 photocell.
I've done some investigation and my current suspicion is the photocell, but direct replacements are no longer available. I've cleaned the windows on the photocell, but they weren't particularly dirty.
I've read that the MZ photocell might be OK, and I've also read that if I were to use a MZ then I should use a new control box. Would a new control box simply slot into place where the existing control box is?
I tried changing the jet nozzle yesterday to the 80S one recommended in the manual, but this didn't work as well as the 80EH jet in there already, so I swapped it back and have ordered a new 80EH jet - although I don't believe this to be the problem.
Any thoughts what my best plan of action is?
Thanks