Hi,
Have just searched the FAQs and so have some ideas about this to add to my existing thoughts but would like others' opinions also please:
Ferroli 77FF combi natural gas, installed in 1992.
In a short period of time, only the last few months, the hot water flow rate reduced noticeably, as did the maximum hot water temperature.
First I replaced the domestic hot water thermostat. No change.
Last weekend I replaced the flow switch, which is the paddle type. This has restored the flow rate to its former glory but the water still doesn't heat enough, which suggests there may have been two problems in the first place.
Interestingly when the hot tap is first turned on, it does briefly heat to the correct temperature but only for about fifteen seconds. Hence why I thought that the flow switch may have been affecting the DHW temp, but it seems I was wrong.
Increasing the hot water potentiometer on the circuit board doesn't help (haven't tried decreasing it to see what happens though).
Thermocouple?
The only other thing I have done recently is replace the fan assembly because of a failed bearing. Doesn't seem likely that this would have an influence though.
Have just searched the FAQs and so have some ideas about this to add to my existing thoughts but would like others' opinions also please:
Ferroli 77FF combi natural gas, installed in 1992.
In a short period of time, only the last few months, the hot water flow rate reduced noticeably, as did the maximum hot water temperature.
First I replaced the domestic hot water thermostat. No change.
Last weekend I replaced the flow switch, which is the paddle type. This has restored the flow rate to its former glory but the water still doesn't heat enough, which suggests there may have been two problems in the first place.
Interestingly when the hot tap is first turned on, it does briefly heat to the correct temperature but only for about fifteen seconds. Hence why I thought that the flow switch may have been affecting the DHW temp, but it seems I was wrong.
Increasing the hot water potentiometer on the circuit board doesn't help (haven't tried decreasing it to see what happens though).
Thermocouple?
The only other thing I have done recently is replace the fan assembly because of a failed bearing. Doesn't seem likely that this would have an influence though.