There's 2 knobs marked as input & output & it's plugged into the wall, I dont know wat to do or how to use them. I'd like my flat warm during the day & at nite instead of cold the now & am having to turn the heater on to really warm the place up. It's a creda No 79368s, at the moment I have the input/output both at 4/5, at night I switch it off from the mains that probably doesn't help, can someone please help me out and explain wat to do. Thanx very much email me on: archie_826@hotmail.com