We have a 30SXi that a local engineer cant seem to get to the bottom of a strange issue we have, its not a problem as such, but is not working as it used to!
When the boiler fires up from cold (on CH or HW) the burner goes to full power and the temp on the panel starts to rise as expected, however within a couple of minutes the temp reaches approx 50c and then the burner and fan start slowing and speeding up again approx every 30-60 secs until the water temp reaches the setpoint (70c) and then behaves as expected by modulating down to maintain. As the burner fan is running at full speed its quite noticeable that its dong this for about 15-20 mins while the water gets to temp.
The flow/return pipes are hot/cold as expected, there is no flow issue, mag filter checked and cleaned.
The PCB was swapped by Glowworm a few years ago due to a fault that blew the board. The engineer tried a different PCB but that did exactly the same thing, the flow/return thermisitors have also been swapped. Its just as baffling for the engineer who also wants to solve it!
Now I don't want to spend loads of money on a 15 year old boiler, but this is a weird problem that is annoying and I'm worried it will develop into something more serious?
Any Ideas/pointers?
Cheers
When the boiler fires up from cold (on CH or HW) the burner goes to full power and the temp on the panel starts to rise as expected, however within a couple of minutes the temp reaches approx 50c and then the burner and fan start slowing and speeding up again approx every 30-60 secs until the water temp reaches the setpoint (70c) and then behaves as expected by modulating down to maintain. As the burner fan is running at full speed its quite noticeable that its dong this for about 15-20 mins while the water gets to temp.
The flow/return pipes are hot/cold as expected, there is no flow issue, mag filter checked and cleaned.
The PCB was swapped by Glowworm a few years ago due to a fault that blew the board. The engineer tried a different PCB but that did exactly the same thing, the flow/return thermisitors have also been swapped. Its just as baffling for the engineer who also wants to solve it!
Now I don't want to spend loads of money on a 15 year old boiler, but this is a weird problem that is annoying and I'm worried it will develop into something more serious?
Any Ideas/pointers?
Cheers