“The heater in a solar tank comes on maybe a few minutes on some days to raise the temperature by a few degrees.”
Quite. So at 8am on January 21st, it having been dark for the best part of seventeen hours (if indeed it was very light the previous day), hc gets up for a wash. Assuming his solar heating did manage to provide a little hot water the previous day, how many minutes do you suppose his auxiliary heater is going to be on for to provide enough water for a wash? How “few” degrees do you reckon the water will have to be raised by to make it warm enough to wash in?
I’m well aware of the issues thanks and make no apologies to you for my sarcasm. If you can’t take a joke you shouldn’t have joined. My suggestion of a different type of boiler would not involve hc changing his heating system and I just thought he’d like it as a consideration.