Help diagnosing a short cycling Ideal Icos HE24 boiler

[Pro heat]

New boiler is the preferred option, those boiler meant to last 10 years anyway.

 

[Chuck]

Assuming the boiler is working correctly, short cycling occurs because the thermostat(s) are calling for heat but the radiators, etc. are dissipating heat at a rate that is too small for the amount the boiler is producing. This is common in older systems that have been zoned and had TRVs fitted. The most straightforward remedy for an end-user is to reduce the room-thermostat setpoint temperature and increase the TRVs setpoint temperatures. The zone control valves should also be synchronised, which helps considerably.

The Worcester Bosch boiler has short-cycling detection built in. If it receives too many on/off calls for heat within a short period (from memory 2 cycles within 5 minutes) it shuts down for 5 minutes (can be adjusted by the installer). This gives the house a chance to cool down a bit so next time the boiler fires up the house can absorb a larger dose of heat. This is far from a perfect solution, but it helps.

C.