What causes furnace circuit board failure?
Failed transistors: The transistors in the control board are susceptible to damage due to power surges, static electricity, and age. Transistors are often the first part of a control board to fail. Loose wiring: The vibrations of the furnace over the years can cause wiring in the control board to shake loose.
How do you know circuit board is bad on furnace?
What are the Signs of a Bad Furnace Control Board?
Warning lights on your furnace’s diagnostic system (see step 1 below)Temperature instability (especially when the thermostat is ok) and;Interruptions in the normal sequencing of your furnace.
Can I replace my own furnace circuit board?
If you’ve determined the circuit board is the cause of your furnace problem, it’s a relatively easy part to replace. The circuit board is usually located in the furnace’s blower chamber near the bottom of the unit. This is where the circulation blower fan motor is mounted.
How long do furnace circuit boards last?
A furnace circuit board lasts 10 to 15 years on average, depending on the furnace condition, usage, and level of maintenance.
How long does it take to replace a circuit board?
Circuit boards can be repaired in one to two days and cost hundreds of dollars less than buying new. Keeping repaired units on hand make for quick on-the-job replacements.
How do you test a furnace circuit board?
Test power going into the control board.
The wire is usually black and labeled as 120VAC Hot. If your furnace has a door switch, you need to make sure that it is pressed in. Use some tape to keep the switch pressed down. If your control board has 120 volts AC going into it, then it has power.
What causes circuit boards to burn?
Three of the main reasons PCBs end up burning are: Extreme heat. Improper component spacing. Component failure or technician error.
Why do control boards go bad?
Transistors are typically the first part to fail in a control board. Once again, the damaging heat and energy that hits those transistors due to voltage spikes, or even a little bit of static electricity, can wear out a board prematurely. This is going to change the composition of the materials they’re made of.
What happens when a furnace transformer goes bad?
If the transformer of your furnace is faulty, it will usually cause the circuit breaker to trip in order to prevent a voltage surge. A surge of voltage may fry various components of your furnace, causing serious damage.
Where is the reset button on my furnace?
Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.
Can you fix a circuit board?
Luckily, it’s possible to repair or remanufacture boards to make them like new again. This does one of two things. Either the board in question can be returned to its original device, making it function again. Or, it can be used in a completely different device, as a form of recycling if you will.
Does a furnace have a motherboard?
A furnace control board is its brain. It’s much the same as any computer circuit board. It operates all functions — and in the order they occur. It controls everything the furnace does during each heating cycle.
Do furnaces have circuit boards?
The control board, also known as a furnace circuit board, is the mastermind of your furnace operation. Circuit boards regulate all the furnace components, including the gas valves, ignition, blower motor, and flame sensor.
