Can any one help with this problem?
On CH it works fine. When DHW the boiler fires up, burner pressure goes up to 9.5 mbar (correct), water from HW tap gets warm (not correct temp for flow). After 20-50 seconds burner pressure modulates down to about 4mbar and then shuts off.
I have monitored the flow and return temps from main heat exchanger, the flow never gets above 80°C. There is about 22°C drop through the plate heat exchanger.
I have tried bridging out the limit stat and the safety stat. this made no difference
The only thing that made the boiler stay on was removing the thermistor from the pipe. This test was repeated about 5 times, and only once did it allow the boiler to run normally! All the other occasions it repeated the above behaviour.
checked the thermistor temp/ resistance 45°C = 5k seems ok
Is it the PCB
Ps does any one have a phone number for Sime technical help
Any ideas!
On CH it works fine. When DHW the boiler fires up, burner pressure goes up to 9.5 mbar (correct), water from HW tap gets warm (not correct temp for flow). After 20-50 seconds burner pressure modulates down to about 4mbar and then shuts off.
I have monitored the flow and return temps from main heat exchanger, the flow never gets above 80°C. There is about 22°C drop through the plate heat exchanger.
I have tried bridging out the limit stat and the safety stat. this made no difference
The only thing that made the boiler stay on was removing the thermistor from the pipe. This test was repeated about 5 times, and only once did it allow the boiler to run normally! All the other occasions it repeated the above behaviour.
checked the thermistor temp/ resistance 45°C = 5k seems ok
Is it the PCB
Ps does any one have a phone number for Sime technical help
Any ideas!
