I thought i'd treat the car today to a full inside valet seeing as the kids had dropped sweets etc on the back seat and maybe they could get rid of some of the water in my front passenger footwell. The inside looks great and i was really pleased with it. The bloke told me to keep the heaters on in the car for roughly an hour to help towards the drying, which i did. But when it came to turning the car off, the heaters stayed on. Someone said that maybe because the car had been on and standing for a while it may take time for the heaters to cool themselves down. So after an hour i went to check the carpets and found the heaters (inside the car) still on and chucking out cold air. I turned the heaters off using the dial inside the car but nothing. The car was off as well as the dial turned to 0 but the heaters were still going strong. Tried starting the car and nothing, the battery was totally flat. After a jump the car started but the heater was still going so we took out the fuse. Just tried putting the fuse back an the heaters are still going. Any ideas anyone??

water has got in somewhere causing a short circuit to a permanent live. that could be at the relay, fusebox, switch, fan, or even any wiring connections inbetween them. i guess the water came from your heater matrix which must be still leaking.