I have an old but extremely reliable (until now) Thorn M54 boiler with Horstmann ChannelPlus controller. The system is fully pumped with no room thermostats and we have checked that the header tank is full. Yesterday we noticed that the controller display was blank. The fuse in the central heating switch had blown. We checked the controller connections but they seemed OK. We replaced the fuse. With the boiler thermostat turned right down, the display returned on the controller, but as soon as we turned the thermostat up the fuse blew again.
Would like to know if this is likely to be a boiler or controller fault (ie whether to call out electrician or heating engineer), also if it indicates terminal trouble in the boiler which we had anyway been expecting to have to replace in near future?
Thankyou in advance for your help
Would like to know if this is likely to be a boiler or controller fault (ie whether to call out electrician or heating engineer), also if it indicates terminal trouble in the boiler which we had anyway been expecting to have to replace in near future?
Thankyou in advance for your help