Furnace repair vs plumber

When heating issues overlap with plumbing — boiler systems, hydronic heating, and condensate drainage. Compare which professional addresses your specific problem.

Heating and plumbing systems overlap more than most homeowners realize, especially in homes with boiler-based or hydronic heating. Understanding where one trade ends and the other begins can save you from calling the wrong professional — and paying for a wasted diagnostic visit ($75–$150). An HVAC technician (furnace repair specialist) handles forced-air gas furnaces, heat pumps, air handlers, ductwork, thermostats, and the combustion/electrical components of boilers. Common furnace repairs include igniter replacement ($150–$300), blower motor repair ($300–$600), heat exchanger diagnosis ($500–$1,500 for replacement), thermostat troubleshooting ($75–$200), and flame sensor cleaning ($80–$150). A complete furnace replacement costs $3,000–$7,000 for a standard efficiency gas furnace or $5,000–$10,000 for a high-efficiency unit. HVAC techs also service the gas and electrical sides of boiler systems — burner tuning, control board replacement, and safety switch diagnostics. A plumber handles the water side of heating systems: boiler vessels, circulator pumps, expansion tanks, radiators, baseboard heaters, radiant floor tubing, zone valves, and the piping that distributes hot water throughout a hydronic heating system. Common plumbing-side heating repairs include circulator pump replacement ($300–$600), zone valve replacement ($200–$400), radiator bleeding and balancing ($100–$300 for a whole-house service), expansion tank replacement ($200–$400), and hydronic loop leak repair ($200–$800 depending on access). Boiler replacement is often a joint effort: the plumber handles the vessel, piping, and water connections ($4,000–$10,000), while an HVAC tech handles gas, venting, and controls. The confusing overlap centers on boiler systems, where gas burns to heat water that circulates through pipes — combining both trades in a single appliance. A good rule of thumb: if the problem involves flame, gas, air, or electrical controls, call HVAC. If the problem involves water circulation, leaks, radiators, or pipes, call a plumber. For condensate drainage from high-efficiency furnaces (the white PVC drain line), either trade can handle it, but a plumber is the safer bet if the drain connects to your home's waste plumbing. Many heating companies employ both HVAC techs and plumbers, making them a one-stop solution for boiler systems.