Hi all
I was hoping someone could advise on what might be causing an issue I'm getting with my boiler / hot water cylinder setup.
For some reason, turning the thermostat on the hot water cylinder up past 40°c causes the boiler to turn on, and if I leave it above 40°c the boiler turns on/off intermittently. Usually every 10/15 mins the boiler would turn on for 10~ mins and turn off again. If I turn the thermostat down, there's a clicking & whirring noise (coming from the metal box next to the cylinder thermostat) and the boiler turns off, and stays off. Also a clicking noise when I turn the thermostat back up, and then the boiler turns on. We have a nest controlling our how water so it should only turn on for 30 mins in the morning and 30 mins late afternoon.
The installer doesn't know what's wrong and insists it's not a fault thermostat. I'm also reluctant to get him back in as I'm not convinced he knew what he was doing as he said it could be a wiring issue but doesn't know.
The setup is quite complicated (at least to me as I know nothing about this) as we have a wiring centre with a nest, underflowing heating hub, cylinder thermostat all having cables going into it. I will attach photo's, but I don't know how useful they'll be considering the mess of cables.
I was just wondering if anyone had seen this issue before and had any recommendations?
Thanks