Boiler Repair Cost: $190 to $660 + Bleed Baseboards (2026)

Installed prices. HomeAdvisor's 2026 average boiler repair is $425; HomeGuide's national average is $300.

Do this now: boiler leaking, cold or smelling of gas

1. Smell gas? Leave now. Do not touch light switches, the thermostat or appliance controls. From outside, call 911 and the gas utility (Southwest Gas; Carrier says to evacuate for a rotten egg smell).
2. CO alarm sounding? Do not look for the source. Get everyone outside, call 911, and stay out until responders say it is safe (CPSC).
3. Water around the boiler? Bryant says to stop using it if it is safe to do so and call a technician.
4. No heat? Check the thermostat, the breaker and the fuel valve, then read the pressure gauge against the range in your manual (Bryant).
5. Protect the pipes while you wait. Open kitchen and bathroom sink cabinet doors and let cold water drip from faucets on exposed pipes (American Red Cross). Keep space heaters at least 3 feet from drapes, furniture and bedding, and never heat the house with the stove, a grill or a generator (CDC).

Is it an emergency? Boiler problems that cannot wait

A boiler is an emergency when you smell gas, a CO alarm sounds, water is spreading, or the house has no heat in freezing weather. Banging, a radiator cold at the top or slowly dropping pressure can usually wait for a weekday visit.

• Yellow or orange flame: HomeAdvisor and Carrier list it as a warning sign. Call before you keep running it.
• Pressure relief valve dripping or spraying: Bryant calls a faulty relief valve one of the most frequent causes of leaks. Call.
• No heat in freezing weather: the Red Cross says to keep heat no lower than 55 F when away so pipes do not freeze.

HomeGuide puts emergency boiler labor at $140 to $210 an hour and the service call at $75 to $200. See emergency HVAC repair for a night or weekend breakdown.

How much does boiler repair cost

Boiler repair costs $425 on average in HomeAdvisor's 2026 data, with most jobs between $190 and $660. HomeGuide puts the national average at $300, a range of $150 to $500, and extremes of $75 to $1,100. By fuel, HomeAdvisor puts gas boiler repairs at $100 to $400, electric at $200 to $450 and oil at $200 to $500. HomeGuide puts the service call at $75 to $200, labor at $75 to $150 an hour and emergency labor at $140 to $210 an hour; HomeAdvisor lists $75 to $130 an hour or a flat $150 to $300.

Boiler not heating: what to check

A boiler that is not heating often has a thermostat setting, a tripped breaker, a closed fuel valve or a pilot problem, according to Bryant and Carrier. Check those first:

1. Thermostat: set to HEAT and above room temperature (Carrier).
2. Power: check for a tripped breaker (Bryant).
3. Fuel: make sure the gas or oil supply valve has not been shut off (Bryant).
4. Pressure: read the gauge and compare it with the range in your manual. Carrier says low pressure can shut the boiler down to protect itself.
5. Pilot: on boilers with a pilot light, Carrier says you can try relighting it by the instructions on the boiler, but never if you smell gas. Bryant says a pilot that keeps going out can mean a bad thermocouple or pilot assembly and needs a technician.

A radiator that is cold at the top and warm at the bottom has trapped air, and Bryant says bleeding it can restore circulation. If the boiler fires but radiators stay cold, a failed circulating pump may be the cause: HomeGuide says a broken pump stops hot water moving through the pipes, and puts a replacement at $300 to $1,100. HomeAdvisor also lists failed transformers, clogged pumps or fuel lines and damaged valves.

Boiler pressure low

Low boiler pressure usually means water has left the system through a leak or a failing expansion tank. Carrier says normal pressure is typically about 1 to 1.5 bar for hot water systems, and to check the exact range in your manual; if pressure drops again soon after it is restored, the cause may be a leak or the expansion vessel. Bryant says to check the gauge against the manufacturer's range and leave pressurized parts to a technician. HomeGuide puts an expansion tank at $200 to $800 installed and HomeAdvisor at $200 to $550.

Boiler leaking

A leaking boiler most often has a faulty pressure relief valve, which Bryant calls one of the most frequent culprits, or a failed expansion tank, worn pump seals, corroded pipes or loose connections. HomeGuide says a faulty expansion tank can cause leaks or overheating. Bryant says if you see water around the boiler, stop using it if it is safe to do so and call a technician. If water has reached floors or ceilings, water damage restoration covers drying it out, and leak detection covers leaks inside walls or under slabs.

Boiler banging, kettling or whistling

Banging or rumbling from a boiler, called kettling, is usually mineral buildup or sludge in the heat exchanger, says Bryant, and needs a professional flush. Carrier adds that trapped air can cause noises and that bleeding radiators may fix it. HomeAdvisor lists banging or whistling, erratic pressure and an orange or yellow flame as warning signs. A yellow flame is also on Carrier's list; treat it as a reason to call.

Boiler repair or replacement

HomeGuide says to replace gas boilers more than 15 years old that need expensive repairs, and HomeAdvisor says replacement often makes more financial sense for units 15 years or older with frequent, costly repairs or a lapsed warranty. HomeAdvisor puts boiler life at 15 to 20 years. HomeGuide puts gas boiler replacement at $3,200 to $9,000; see boiler replacement cost for prices by fuel and type. A warm-air system works differently; see furnace repair if you have ducts and vents instead of radiators.

Boiler repair near me: who to call and what to ask

Carrier says boiler components involve gas, combustion and high-voltage electricity, and Bryant says not to repair gas or pressurized components yourself. HomeGuide says servicing a boiler yourself is hazardous without training, and CPSC says to have fuel-burning heating systems professionally inspected every year. Licensing varies: Arizona's ROC has a separate R-4 boiler classification. TheHVAC license table covers six states.

• What is the call-out fee? HomeGuide puts it at $75 to $200.
• Gas, oil or electric experience? Ask whether the company services your fuel and brand.
• Can you test the expansion tank and relief valve on the same visit if pressure is the problem?
• Is there a maintenance plan? HomeGuide puts an annual gas boiler plan at $200 to $500.

If the boiler also makes your hot water, see water heater repair for tank problems. Boiler repair is one line in home repair costs. Calls go to an independent company that serves your area and takes this kind of job. How calls work.

How to bleed baseboard radiators and heaters

Bleed a hot water baseboard or radiator when it is cold at the top and warm at the bottom, which Bryant says means trapped air is blocking circulation. The Missouri Public Service Commission says to remove trapped air from hot-water radiators once or twice a season, and to call a professional if you are not sure how. These steps are for hot water systems; if you have steam heat, call instead.

1. Find the cold ones. With the heat running, carefully feel the tops of each baseboard or radiator (Baxi).
2. Turn the heat off and let them cool. Baxi says to switch off the heating first. The water that comes out is hot (Montana State University Extension).
3. Get the tool and a cloth. Most bleed valves take a radiator key; some take a flat screwdriver. Hold a cloth or small container under the valve (Baxi).
4. Open the valve slowly. Turn it counterclockwise a little at a time. You should hear air hiss out (Baxi).
5. Close it when water comes out. Shut the valve tightly once water flows instead of air (Baxi, MSU Extension). Repeat on each cold unit.
6. Check the boiler pressure. Compare the gauge with the range on the boiler or in its manual (Bryant). If it is now below the range, call; Bryant says to leave pressurized components to a technician.
7. Turn the heat back on and recheck. If cold spots come back, Baxi says sludge may be blocking the system and a flush is needed. HomeAdvisor puts flushing at $200 to $600.

Rust or water around a radiator can mean a leak (Baxi). If bleeding does not fix the cold spots, or the pressure keeps dropping, call the heating and AC line rather than draining or refilling the system yourself.