I have a Keston 80 that runs CH and HW via Honeywell zone valves and two Grundfos Selectric pumps. All have worked correctly in the past.
Now, when the controls call for heat, the valves open, pumps come on, boiler blower comes on, followed finally by the boiler firing in the cylinder and hot water begins to flow. All normal i think.
However, the boiler shuts down within 20 seconds, with the blower almost immediately starting again, followed by re-ignition again 20 secs later. The whole cycle repeats every 20 secs or so, so i am only getting heated water flowing for 50% of the time.
Radiators are warm, but not hot, so the water does seem to be reaching them, but as is only being heated for 50% of the time, it is only warm.
Any ideas gratefully received!
Now, when the controls call for heat, the valves open, pumps come on, boiler blower comes on, followed finally by the boiler firing in the cylinder and hot water begins to flow. All normal i think.
However, the boiler shuts down within 20 seconds, with the blower almost immediately starting again, followed by re-ignition again 20 secs later. The whole cycle repeats every 20 secs or so, so i am only getting heated water flowing for 50% of the time.
Radiators are warm, but not hot, so the water does seem to be reaching them, but as is only being heated for 50% of the time, it is only warm.
Any ideas gratefully received!
