the average cost to hire a plumber ranges from $ 170 to $ 430 cost of hiring a plumber is usually calculated in one of 3 waysper hour rate usually with a 2 hour minimum or flat fee for service call hourly rate orflat fee per job often payable in increments for a large job 750 $ 1000 water heater install tankless $ 1500 $ 1850 cost breakdown the cost to hire a plumber includes labor confirm with your plumber how labor costs will be calculated by the hour or at a flat rate