both pipes are hot in and out.if i let my car warm up without heaters on then switch them on they will be hot for a bit and then go cold so i switch them off to let them warm up again etc as its brass monkeys at the moment.and my temp gauge stays so low i never have to switch the cooling fan on(manual)unless im stuck in traffic.do i have to take the dash or can i get the matrix out with the centre console out of the way?its a frst and cheers for any help guys