Mountain View, CA

How much does it cost to service and repair a boiler?

$70 – $350 routine boiler service cost
$150 – $700 average boiler repair cost

Get free estimates from boiler services near you, or view our cost guide below.

March 15, 2022

Reviewed by Tom Grupa and 2 expert boiler services on HomeGuide.

Boiler service cost

Boiler service costs $70 to $125 for an inspection or $150 to $350 for cleaning. The average cost to repair a boiler is $150 to $700. Annual gas boiler services cost $200 to $500 for a tune-up, cleaning, and repairs. Minimum call-out charges for boiler repairs are $75 to $200.

Boiler service cost - chart
Boiler service cost - chart

Boiler service cost
Service Average cost
Inspection $70 – $125
Annual maintenance plan $200 – $500
Service call / flat fee call-out charge $75 – $200
Boiler cleaning or descaling $150 – $600
Hourly rates $75 – $150
Average repair cost $150 – $700

Average cost to repair a boiler

The following table shows the average cost to service or repair a boiler.

Average cost to service or repair a boiler
National average cost $300
Minimum cost $75
Maximum cost $1,100
Average cost range $150 to $500

Cost data is from research and project costs reported by HomeGuide members.

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Boiler service costs by fuel type

Boiler service costs depend on the unit’s fuel type and the extent of the maintenance or repairs required.

Boiler service costs by fuel type
Type Average cost
Gas $100 – $400
Oil $150 – $500
Electric $150 – $450

*Prices include parts and labor.

Contractor repairing and servicing boiler
Contractor repairing and servicing boiler

Gas boiler repair service cost

A gas boiler inspection and repair service costs $100 to $400 on average. Replace gas boilers more than 15 years old that require expensive repairs. A gas boiler replacement costs $3,200 to $9,000 on average.

Common problems include:

  • Replacing faulty temperature, gas, or pressure regulator valves
  • Changing out damaged circulating pumps
  • Flushing air out of the system pipes
  • Upgrading damaged transformers or igniters
  • Changing loose wiring connections
  • Repairing natural gas fuel lines
  • Heat exchanger replacement
  • Upgrading the expansion tank

Oil heating boiler service cost

An oil heating boiler service costs $150 to $500 on average for most repairs. Heating-oil tank replacements cost $1,000 to $6,200 if the old tank is leaking beyond repair.

Common problems include:

  • Fixing pipes to stop fuel-oil line leaks
  • Replacing faulty oil burners & transformers
  • Changing out a clogged heating-oil pump
  • Replacing the oil-boiler chimney flue to prevent misfiring
  • Flushing air out of the fuel line
  • Loose wiring connections
  • Replacing damaged valves
  • Upgrading the expansion tank
  • Replacing the heat exchanger

Electric boiler repair estimate

An electric boiler repair costs $150 to $450 on average. Electric boilers have no risk of gas or fuel leaks and don’t have air filters, fans, or vents to clean.

Common problems include:

  • Circulating pump replacement to balance water pressure
  • Electrical wiring repairs to solve connection failures
  • Valve replacements to fix water leaks
  • System flush to remove trapped air or clogs in radiators
  • Thermostat repair or replacement to improve heat control
  • Heat exchanger replacement to boost heating capacity

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Boiler repair costs

The average cost to repair a boiler is $150 to $700, depending on the condition, brand, size, accessibility, and how many parts need upgrading. Alternatively, a boiler replacement costs $3,200 to $9,000 on average.

Boiler repair costs
Service Average cost
Circulating pump replacement $300 – $1,100
Zone valve replacement $100 – $500
Expansion tank replacement $200 – $800
Gas valve replacement $200 – $900
Radiator valve replacement $125 – $300
Coil replacement $500 – $1,000
Fan replacement $200 – $500
Transformer replacement $150 – $500
Flue replacement $300 – $700
Ignitor replacement $100 – $400
Water pipe leak repair $150 – $850
Thermostat replacement cost $140 – $350
Electrical work and repair cost $140 – $420

*Minimum call out charges for boiler repairs are $75 to $200.

Boiler circulating pump cost

Replacing a boiler circulating pump costs $300 to $1,100 on average, depending on the brand, size, and speed. This pump is necessary to spread heat through the home. A broken circulating pump won’t send hot water from the tank through the heating system pipes.

Zone valve replacement cost

A boiler zone valve replacement costs $100 to $500 on average. Zone valve installation costs depend on whether the system needs new piping. The zone valve controls room temperatures by directing the flow of water or steam to each room.

Boiler expansion tank replacement cost

A boiler expansion tank replacement costs $200 to $800, depending on the system type, size, and whether it needs a new relief valve also. Faulty expansion tanks cause boiler leaks or system overheating.

Costs to replace a combi boiler’s external expansion tank are the same. However, smaller combi boilers have an internal expansion tank that, once damaged, may require a full boiler replacement.

Boiler gas valve replacement cost

A boiler gas valve replacement costs $200 to $900 on average, depending on the part type. Replacing the gas valve requires removing and reconnecting to natural gas lines. Always hire a professional for gas-line work.

Boiler radiator valve replacement cost

The cost to replace a boiler radiator valve is $125 to $300 on average, depending on the valve type. Common types include:

  • Steam radiator valves
  • Thermostatic valves
  • Modulating temperature control valves
  • Smart valves

Boiler coil replacement cost

A boiler coil replacement costs $500 to $1,000 on average, depending on the model and size. If hard-water minerals clog the boiler coil, then the gasket, piping connections, and valves may also need replacing.

Boiler fan replacement cost

The cost to replace a boiler fan is $200 to $500 on average, depending on the brand and size. The induced draft blower is an exhaust fan essential for pushing the boiler’s combustion fumes outside through the vent or chimney.

Boiler transformer replacement cost

Replacing a boiler transformer costs $150 to $500 on average, excluding replacing any other wiring or thermostat work. Prices depend on the part type, voltage rating, and whether it’s part of a full external spark transformer kit.

Boiler flue replacement cost

A standard boiler flue replacement costs $300 to $700, depending on the length and material. Installing a stainless-steel chimney liner costs $900 to $3,800. This heating duct or vent pipe carries the boiler’s combustion fumes out of the home.

  • Gas boilers have a wide range of vents like PVC pipes or metal ducts.
  • Oil boilers typically connect to chimneys because they require stainless steel vents or flues.
  • Electric boilers don’t need vents because they don’t produce fumes.

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Boiler service and tune-up cost factors

Boiler inspection and cleaning costs depend on the system’s fuel source and the service type.

Hourly & annual boiler service charges
Service Average cost
Flat call-out charge for repairs $75 – $200
Hourly service rates $75 – $150
Emergency hourly service $140 – $210
Annual service contract $200 – $500
Boiler inspection $70 – $125
Gas and oil boiler cleaning $150 – $350
System flush and descaling $150 – $600
  • Service type – Basic inspections don’t include part replacement. However, annual service contracts cover some parts and a full cleaning.
  • Boiler type & fuel source – Servicing oil boilers typically costs more than inspecting and cleaning a gas boiler.
  • Labor – Rates increase for difficult-to-access unit locations and emergency calls. Some technicians have flat rates, or they charge hourly for complex jobs.
  • Warranty – Companies offer free replacement boiler parts for 5 to 10 years, excluding labor.
  • Insurance – Homeowners' policies sometimes cover repairs or replacements due to natural disasters.
  • Maintenance frequency – Tune-ups often cost most for systems that haven’t had annual service.
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Fixed call-out charge for boiler repair

Fixed call-out charges for boiler repairs are $75 to $200 on average and typically include the first hour of labor. Boiler services charge $75 to $150 per hour plus parts.

Annual boiler service charge

Annual boiler service charges are $200 to $500 on average, depending on the service contract.

Yearly boiler maintenance costs typically include:

  • System pressure checks
  • Discounts on call-out fees
  • Emergency repairs
  • Replacing basic parts like gaskets at no extra charge
  • Discounted repairs
  • Combustion-setting adjustments with a calibrated analyzer
  • Testing connections
  • Leak checks
  • Condensation-drain cleaning for high-efficiency models
  • Burner & exhaust-vent cleaning
Repairs with custom-order replacement parts are not part of most tune-up packages.

Boiler inspection cost

A boiler inspection costs $70 to $125 on average, not including repairs. The HVAC technician diagnoses any problems and offers repair options. Many companies sell boiler checks as part of larger boiler maintenance or tune-up packages.

Inspections include:

  • Combustion analysis
  • Carbon-monoxide leak tests
  • Checking all electric connections & thermostat relays
  • Testing all burners, valves, & exhaust flues
  • Radiator & piping checks
  • Diagnostic reports

Gas and oil boiler cleaning cost

Cleaning a gas or oil boiler costs $150 to $350 on average. Some HVAC companies offer boiler cleaning as part of their annual service agreement plans.

Technicians typically clean:

  • Heat exchanger tubes
  • Vent stack
  • Airflow inlets
  • Air filters
  • Burners

Boiler flush and descaling cost

A boiler system flush costs $150 to $600 on average. The cost of descaling a boiler depends on the size, pipe length, and amount of sediment buildup. Places with hard water need the most descaling.

  • Installing a water softener costs $800 to $2,500 to prevent scale buildup and extend the life of hot-water appliances.
  • Clearing mineral deposits from the pipes prevent the system from overheating.

Commercial boiler service prices

Commercial boiler service prices are $75 to $150 per hour, plus parts. Commercial contractors typically charge per hour due to additional complexities of industrial-size boilers. Most state regulations require annual inspections of industrial boilers.

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Frequently asked questions

How long does it take to service a boiler?

Servicing a boiler takes 30 to 90 minutes on average for an inspection and general maintenance, depending on the boiler type, age, model, condition, and accessibility.

  • Servicing a gas boiler takes 30 to 60 minutes.
  • Servicing an oil boiler takes 1 to 3 hours.

Is it worth servicing a boiler?

Servicing a boiler is worth it to:

  • Stop carbon monoxide poisoning.
  • Maintain warranty coverage.
  • Prevent expensive repair and breakdowns.
  • Keep the machine running at its top-efficiency level.
  • Prevent fires from burner failures.
  • Avoid pipe corrosion.
  • Stop pressure buildup inside the boiler that leads to explosions.
  • Avoid water leaks.
  • Increase the unit’s lifespan.
  • Stop utility bills from rising.

How often do I need to service my boiler?

A new boiler needs its first service 1 to 2 years after installation. After that, boilers typically need yearly servicing, and annual inspections are mandatory in some states.

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Getting free estimates for boiler repair

Servicing your boiler yourself is illegal and hazardous without proper training. When hiring a boiler service near you, be sure to:

Questions to ask

  • How long have you been servicing boilers, and can I see references from past jobs?
  • Which kind of boiler and brands have you worked on the most?
  • Can you show me quotes for repairing vs. replacing these parts?
  • Do you check my thermostat functions and connections?
  • Will you subcontract any part of these repairs to an electrician or plumber?
  • What can you do to improve the energy efficiency of this unit?
  • How much are your maintenance plans?
  • Which additional costs are not part of the annual service plan?
  • How long will the repairs take?
  • What does the warranty cover, and how long does it last?
  • Did the old boiler fail from lime-scale buildup, and if so, how can I stop it?
  • What’s your payment schedule?
  • For a gas boiler, can you do a combustion analysis test to check for gas leaks?

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