if you just looking for ammunition why do you pay a reputable firm to check the work done with the quote you got from the warm front guys. they should be able to tell you and give a report on what they find.
hi, you may want to check the pump is installed correctly, incorrect installation of the pump maybe causing air to be sucked in, it will reduce the amount of water that the pump can circulate. check where the hot water pipe has been taken off the cylinder with the instructions or pictures of...