Hi all, I hope someone here can help me shed some light on some of the problems we're having. First I'll lay out some facts....

We moved into this property 4 months ago and are experiencing extremely high electric bills in return for what I would regard as poor performance.

We have radiators with thermostats in all rooms except the open plan living/kitchen/dining room where there are two convection type heaters/air cooling. No underfloor heating.

I'm sat here where the heating has been on all day and the house has not gone above 19.5C despite setting the convectors to 21C. The main thermostat is set to 21C. This always happens when the temperature outside drops below 0C. It's like the system can't cope.

Despite failing to reach the temperature we'd like my smart meter tells me we've used £13 of electric today! I have a 16kw solar panel array that is supposed to be supplementing this as well. I am on the cheapest tariff that I can find by the way. Once outside temps drop below 5C our bills don't go below £10 a day.

We have had an engineer out and also had a full service. He was unable to shed light on the high bills.

My hot water is set to 50c and is always hot.

There is one setting on the boiler "heating" homepage called "offset" this ranges from -10c to +10c. If have fiddled with this up and down but cannot see what difference is made either way. There is nothing in the manuals about this setting. Can someone please shed some light on that?

Sorry for such a long post but I thought it best to give as much info as possible. Any help would be much appreciated.