. Upon arrival found pressure switch tripping out. Cleared the hoses and it was still acting up. I jumped the pressure switch out and it still trips. Pressure switch is bad. Ordered one from carrier. Customer has parts warrenty. Looked at the water heater and the gas was off turned the gas in and the water heater came on and ran for a put 5 minutes. No codes or anything. Customer said he would like for us to wait to look at the upstairs due to it not being used. Will need to return to put pressure switch on when it arrives. I ordered part to come to the shop.