I have a 10 year old Ferroli 701. The circuit board was replaced 9 months ago.
The problem I have is the hot water cuts out momentarily at the taps while the demand light is still on. When watching the boiler flames after a minute or so, they appear to drop as if the gas valve is modulating for low demand (which hasn’t changed and is on full). At this point the gas is either cut for 10 seconds before being ignited again or it just rights itself for a random amount of time before doing it again – this is all with the demand light on.
I’m guessing it’s difficult to diagnose from this description but what other information do you require.
PS it may be relevant but I have previously had problems with the CH coming on if the temp setting is low. When cold, there appears to be a delay between the point where gas valve is open and actual ignition – this can be smelt outside near the flue. If I turn the heat setting higher, it seems to ignite quicker.
Where do I start with diagnosis – would simple tests on temp sensor/flow sensor be a good start? What factors modulate the gas valve?
Many thanks
Jeremy
The problem I have is the hot water cuts out momentarily at the taps while the demand light is still on. When watching the boiler flames after a minute or so, they appear to drop as if the gas valve is modulating for low demand (which hasn’t changed and is on full). At this point the gas is either cut for 10 seconds before being ignited again or it just rights itself for a random amount of time before doing it again – this is all with the demand light on.
I’m guessing it’s difficult to diagnose from this description but what other information do you require.
PS it may be relevant but I have previously had problems with the CH coming on if the temp setting is low. When cold, there appears to be a delay between the point where gas valve is open and actual ignition – this can be smelt outside near the flue. If I turn the heat setting higher, it seems to ignite quicker.
Where do I start with diagnosis – would simple tests on temp sensor/flow sensor be a good start? What factors modulate the gas valve?
Many thanks
Jeremy