My boiler which is about 7 years old has pretty much stopped responding to the room thermostat (Danfoss TP5) after its initial daily start up. It is usually triggered in the morning, occasionally later than it should but sometimes not at all.
If I turn on the hot tap until the boiler fires up and then turn off the tap the heating starts working. The boiler sometimes keeps the flame from the hot water but usually switches off and then fires up after a short time of 5-60 secs. The temperature gets up to around 60, holds for a few minutes and then shuts down. The thermostat is still calling for heat. I can repeat this cycle endlessly so I can have the heating on all the time but I have to run the hot tap every 10 mins.
I had this problem during the cold snap in January at which time the thermostat was replaced, that had no affect. It then seemed to be fine until this current cold snap.
I've tried to use the diagnostic but not found any error. The two green lights flash, 1 sec on, 1 sec off, while the boiler is heating and then it goes back to the first green light flashing 1 sec on, 1 sec off.
I disconnected the thermostat and then reconnected at which point the boiler started up, ran a few mins and then stopped again.
Seems the problem is with the room thermostat.
If I turn on the hot tap until the boiler fires up and then turn off the tap the heating starts working. The boiler sometimes keeps the flame from the hot water but usually switches off and then fires up after a short time of 5-60 secs. The temperature gets up to around 60, holds for a few minutes and then shuts down. The thermostat is still calling for heat. I can repeat this cycle endlessly so I can have the heating on all the time but I have to run the hot tap every 10 mins.
I had this problem during the cold snap in January at which time the thermostat was replaced, that had no affect. It then seemed to be fine until this current cold snap.
I've tried to use the diagnostic but not found any error. The two green lights flash, 1 sec on, 1 sec off, while the boiler is heating and then it goes back to the first green light flashing 1 sec on, 1 sec off.
I disconnected the thermostat and then reconnected at which point the boiler started up, ran a few mins and then stopped again.
Seems the problem is with the room thermostat.
