What to do if radiators do not get hot with Jolly Mec MEC 21-18 kW Boiler?
- CCathy GordonAug 19, 2025
If the radiators do not get hot even if the water in the Jolly Mec boiler is hot and the pump is running, it might be due to air in the system. Vent all radiators, pump, and boiler to resolve this. Also, check whether any intercepts (zone valves) are closed.