A boiler repair costs $150 to $700 on average with a minimum $75 to $200 call-out fee that typically applies toward the total bill. Extended work costs $75 to $150 hourly for labor alone. The most expensive boiler repairs are coil or circulating pump replacements that cost from $300 to $1,100.

You typically need a boiler repair when you notice these signs:

• The thermostat connected to the boiler isn't working.
• You smell unusual gases around the boiler unit.
• The boiler makes an irregular sound while running.
• Pipes to or from the boiler are corroding.
• You find dark marks on the boiler tank near the wiring connections.
• Water pools around the boiler from leaks.
• Heating bills are increasing.

You should repair your boiler when fixing it costs less than $600 to $1,000 or if the manufacturer's warranty is still valid to help cover repair fees. However, you should typically replace your boiler if it's more than 15 years old or costs more than $2,000 to repair.

A boiler replacements costs $2,200 to $7,000 for standard units or $4,000 to $10,000 for high-efficiency models. This price includes disposal of the old boiler as well as new wiring and plumbing connections. A new hot water tank is sometimes also necessary in some home systems.

You need to service your boiler every 1 to 2 years in most states, especially since many boilers run on natural gas that can leak from pipes that aren't well-maintained. State laws typically require regular boiler inspections to prevent fire hazards and gas poisoning. Check with your local building department for more information.

A boiler inspection costs $70 to $125 and typically doesn't include replacing any parts or repairs unless the service is part of an annual maintenance plan. You should receive a detailed diagnostic report when the inspection is over to keep for your maintenance records. These files are important for any insurance or warranty claims you may need to make in the future.

A complete boiler inspection should check all the following:

• Full combustion analysis to assess the boiler's efficiency
• Carbon-monoxide leak tests
• Testing all electrical connections and thermostat wiring
• Examining all burners, valves, and exhaust vents
• Checking the radiators and all connected piping

Yearly boiler service with a tune-up cost $200 to $500 for cleaning, general repairs, and a complete inspection. If you need custom part orders for specific brands, then replacement parts sometimes cost extra, depending on the service contract.

Hire a boiler technician, plumber, or qualified HVAC professional to repair and service the unit. Browse through our list of nearby contractors to compare services.

Use the following hiring checklist to help you:

• Choose pros with certifications from a local board of boiler and pressure valve inspectors or other HVAC technician associations.
• Compare 3+ boiler repair quotes from experienced installers.
• Select licensed, insured, and bonded contractors.
• Avoid the cheapest quotes that signal low-quality work.
• Review their ratings on HomeGuide and Google.
• Request copies of estimates, plan diagrams, warranties, and contracts.
• Verify the estimate lists all materials, labor, and equipment costs.
• Don’t pay in full upfront.

• How long have you been repairing boilers?
• Can I see references from past jobs?
• Which boiler brands have you worked on the most?
• How much is the cost of repairing vs. replacing this boiler?
• How detailed is your boiler inspection?
• If I get the annual service plan, which added costs are not part of it?
• How long will it take to order a new part?
• Do you offer a warranty?
• For a gas boiler, can you do a combustion analysis test to check for gas leaks?