Should you replace the circuit board in a furnace?

Author: Jace Wyman  |  Last update: Tuesday, May 26, 2026

A control board failure is a major furnace problem. It may require replacing the appliance, depending on the unit's age and the severity of damage. The things to do when your heater won't turn on won't help if the furnace control board has gone bad. If it's not fixed, the entire system can malfunction.

Is it worth replacing a control board on a furnace?

Conclusion. Replacing a furnace control board is an essential aspect of maintaining the efficiency and safety of your home's heating system.

What is the life expectancy of a furnace circuit board?

The average furnace circuit board, also referred to as its “motherboard,” will last anywhere between 10 and 15 years.

What is the most expensive part to fix on a furnace?

A heat exchanger replacement is often one of the most costly repairs in a furnace, and the expense can sometimes rival that of installing a new furnace. Typical replacement costs vary widely but can easily reach several thousand dollars, especially if labor costs are factored in.

How do I know if my furnace circuit board is bad?

Control boards can fail for various reasons, but the tell-tale symptoms look the same:
  1. Warning lights flashing or staying on.
  2. Inability to settle on a stable temperature.
  3. Stuttering or interrupted furnace sequence.

Furnace/AC How to Troubleshoot The Control Board

How much does it cost to replace a furnace circuit board?

Depending on how technologically advanced your current furnace is, replacement costs for a new circuit board can run from around $300 to $1,200.

What causes the circuit board to go out on a furnace?

Power Surges. Speaking of electrical discharge, another form of this can occur as a power surge. Power surges can come from faulty wiring, lightning strikes, or electrical overload. The energy from the surge can fry the furnace circuit board, making it unsalvageable.

Is it worth fixing a 20 year old furnace?

Repair: If your furnace system is less than 15 years old and the cost of repair is less than half the cost of replacement. Replace: If your furnace system is more than 15 years old and requires a costly repair to maintain efficiency.

What is the most common furnace failure?

One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn't working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.

Does insurance cover furnace failure?

While there's no such thing as furnace or boiler replacement insurance, homeowners insurance may cover the cost to replace your furnace or boiler if it's damaged or destroyed by a covered peril.

Can I replace my own furnace circuit board?

By working on your HVAC system or undergoing important repairs on your own, you could void your unit's warranty or further damage the system. Leave HVAC repairs to the pros.

How do I know if my circuit board is bad?

Start with a Visual Inspection

Often, circuit boards deployed in the field are damaged by electrical surges and there are telltale signs on the PCB. Look for a burnt spot, particularly on the power supply module or I/O and connectivity ports. Pay attention to cracked ICs, broken traces, and blown capacitors.

What blows a circuit board furnace?

Faulty and loose wires can create electrical shorts that blow out a control board fuse. The furnace's vibrations can loosen control board wires over time and prevent them from sending information to the unit.

How long does it take to replace a furnace circuit board?

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

What is the best furnace brand?

The 5 Best Furnace Brands
  • Carrier Furnace: Best Warranty.
  • Lennox Furnace: Best Company Reputation.
  • Bryant Furnace: Best for Durability.
  • Trane Furnace: Most Years of Experience.
  • Amana Furnace: Best for Efficiency.

Can you reset the furnace control board?

Knowing how to reset the furnace control board requires you to find the reset button. However, not all furnaces have a reset button. If your electric furnace has one, you'll most likely find it next to the motor, located within the blower housing. If you own a gas furnace, you'll probably find it in the control panel.

What fails first on a furnace?

If the flame sensor fails, your furnace may not be able to start or may shut down shortly after starting. Common causes of flame sensor failure include corrosion, dirt buildup, or a broken wire. The gas valve controls the flow of gas to the furnace. If the gas valve fails, your furnace won't be able to produce heat.

Why do furnaces only last 10 years?

Lack of Routine Maintenance

When you ignore recommended maintenance, dirty buildup on heat exchangers, burners, fan blades can reduce you're the life of your furnace in a number of ways: Restricted airflow from dirty filters can make the system work harder. Imbalanced fans can affect the life of motors.

Why is replacing a furnace so expensive?

Installation Entails More than Just the Furnace

For a gas-powered furnace, a contractor must set up a gas connection and vent. Installing an electric furnace requires running wiring, adding a circuit breaker, or perhaps updating an electrical panel. Holes are often drilled for pipes and wires.

Can furnaces last 30 years?

1. Replace your oil furnace or gas furnace as it approaches the end of its furnace life expectancy. Furnace life expectancy ranges from 15-30 years on average. A well-maintained furnace can last 15 to 20 years with proper care.

Is it better to undersize or oversize a furnace?

Even a slightly undersized furnace will accomplish the job the majority of the time. Taking things down a few sizes will more than likely solve some of your common heating problems like too high of a utility bill while half of your house is blazing and the other half is an icebox.

What are the symptoms of a bad furnace circuit board?

Now that you know where the control board is and what it does, let's explain the top signs that your control board is malfunctioning.
  • Illuminated Warning Lights. ...
  • Immobilized Switches on the HVAC Control Board. ...
  • Faulty Soldering Connections. ...
  • Interrupted Sequencing. ...
  • Temperature Regulation Issues.

How do you diagnose a bad circuit board?

Visually inspect the circuit board for obvious problems such as overheated components or bad connections. Look for small brown burn marks indicating overheated components that should be replaced. Check for bulging components or dull-looking connections as indicators of error.

Can a faulty circuit board cause a fire?

Overloading: When a PCB is overloaded with too much current, it can cause the board to overheat and lead to a burnt circuit board. Poor ventilation: A PCB that is not properly ventilated can also overheat and catch fire.

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