How much does a furnace control board replacement cost?

Furnace control board replacement cost

A furnace control board replacement costs $300 to $650 on average. A furnace circuit board or motherboard costs $50 to $300 for the part alone, plus $250 to $350 for replacement labor. HVAC contractors charge $75 to $150 per hour for furnace repairs.

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

• Circuit board replacements take 20 to 30 minutes on average.
• A furnace control board lasts 10 to 15 years on average.

Furnace circuit board or motherboard cost factors

Furnace circuit board or motherboard costs depend on the board brand and type, job complexity, and the HVAC system conditions.

Furnace circuit board replacement cost factors include:

• Furnace inspection and diagnosing – A furnace inspection costs $70 to $130 on average and typically includes safety and performance testing and a tune-up.
• Furnace brand and age – Original manufacturer parts cost more than universal parts.
• Furnace efficiency – Parts and labor for the high-efficiency, two-stage furnace models cost more than single-stage models.
• Circuit board type
  • Simple ignition control – Less-expensive boards in older, less-efficient furnace models
  • Integrated furnace control – More expensive and efficient boards capable of more complex tasks
• Labor – Metropolitan labor rates typically cost more than hiring a pro in rural areas. Extra labor time applies for hard-to-reach furnace locations.
• DIY vs. contractor – Replacing an ignitor saves $250 to $350 in HVAC technician labor but voids some warranties.
• Warranty – Most furnaces come with a 5- to 10-year warranty on parts.

Furnace control board labor cost

The labor cost of a furnace control board replacement is $250 to $350 on average, depending on the location and technician’s skill level.

• Furnace repair contractors charge $75 to $150 per hour.
• Minimum service fees are $75 to $200, which includes the first hour of work.
• HVAC emergency service costs $140 to $210 per hour for repairs outside of regular hours.

How to tell if a furnace circuit board is bad

To tell if a furnace circuit board is bad, check for the following warning signs:

• The indoor temperature is too hot or cold, and the thermostat is working.
• The blower motor is stopping suddenly and frequently.
• Flashing LED warning lights are visible on the control board.
• The furnace smells of burnt plastic.
• Burn marks are on the control board.

How to test and check a furnace control board

To test and check a furnace control board:

1. Unscrew and remove the service panels.
2. Tape down the door switch to keep power running to the furnace.
3. Locate the control board behind the lower access panel, in front of the blower.
4. Check the control board for flashing warning lights.
5. Consult the chart on the inside of the panel lid to translate the warning light sequence code.
6. If the light is off, then there is no power going to the control board, which means the problem is not the board but an electrical issue.
7. A voltage meter is necessary if the control board does not have an indicator light.

A voltage meter is the only surefire way to diagnose a faulty control board and requires the working knowledge of a licensed HVAC technician to use it properly.

What causes a furnace circuit board to fail?

Causes of a failing furnace circuit board include:

• Old age of the circuit board
• Blower motor failure
• Chemical contamination
• Clogged air filter
• Dirt, dust, and debris buildup
• Excess heat, moisture, and condensation
• Failed circuit-board connections
• Faulty starting capacitor
• Loose wiring
• Power surges and dips
• Static electricity
• Stuck relays and switches
• Mismatched fuse connections
• Corrosion of the board or its connections

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Frequently asked questions

What does a furnace control board do?

The furnace control board powers and regulates all heating functions, including the gas valve, ignition, the fan’s blower motor, burner unit, heat exchanger, and flame sensor. Furnace motherboards relay thermostat settings to the furnace to create the desired home temperatures.

Where is the control board on a furnace?

The furnace control board is typically inside the lower part of the unit near the blower motor chamber. Technicians must unscrew the lower access panel to reach it.

How long does it take to replace a furnace motherboard?

Replacing a furnace motherboard takes 20 to 30 minutes on average, depending on the furnace type, circuit board location, and accessibility. HVAC technicians may take up to 1 hour to run additional heating-system diagnostic tests.

How long does a furnace circuit board last?

A furnace circuit board lasts 10 to 15 years on average, depending on the furnace condition, usage, and level of maintenance. Annual furnace inspections and filter cleaning optimize performance so that circuit boards last longer.

Where to buy a furnace control board

Homeowners buy furnace control boards from:

• Online appliance parts suppliers, HVAC parts distributors, or Amazon
• Local HVAC service companies
• Furnace brand manufacturers (for exact part matches)

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Hiring a furnace repair service

Before hiring a furnace repair service near you:

• Get at least three estimates to compare.
• Verify that the HVAC contractor has state and local licenses.

• Check for certifications from:
  • NATE (North American Technician Excellence)
  • American Society of Heating, Refrigeration, & Air-Conditioning Engineers (ASHRAE)
  • HVAC Excellence
  • Other local HVAC training programs
• Look at their reviews on HomeGuide and Google.
• Seek certified, insured, and bonded companies with 5+ years of experience.
• Get a written estimate, contract, and warranty before work begins.
• Avoid companies with the cheapest quotes as quality may suffer.
• Don’t pay in full upfront. Follow a payment plan and save receipts.

Questions to ask

• Can you show me a list of references?
• Do you provide free estimates?
• How long will the job take?
• What can I do to make my furnace control board last longer?
• Do I need an HVAC power-surge protector?
• Should I turn my furnace off when I’m not home?
• Can you recommend ways to increase the efficiency and lifespan of my HVAC system?
• Do you use original equipment manufacturer parts?
• Can you provide an ongoing HVAC maintenance plan?
• What does your warranty or guarantee include?
• Will you provide a written report summarizing the repairs and maintenance?

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