Loclnor

Sorry I meant it is the water tank and buffer tank and pumps that are in the loft - the ASHP is outside. Thank you both for your help.

Please can someone tell me. My installer has told me to leave the heating setting on my ASHP 'on' in the summer months and just control it by using the hand held thermostat (putting it down to 10 degrees in the summer months), rather than turning the heating off altogether. The system is installed in the loft and controls radiators only. I can hear some noise coming from the loft when the heating is left on like this. .......... I am wondering by leaving the system 'on' is it heating up the buffer tank - is that the background noise I can hear? Also is it going to cost me more to keep the system 'on' although it is not heating any radiators up please?