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.
ESD or static electricity will cause a furnace control board to fail over time. Electronics fail over time, but other damage caused by a power outage, power surge, or another voltage spike like someone taking a power pole out. A blown fuse can prevent the circuit board from working too.
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.
Here are some of the most common causes of control board failure: A power surge from outages or lightning strikes. Cold weather causes the control board's components to freeze up. Age, wear and tear.
Overheating due to overloading, poor ventilation, short circuits, or component failure are the primary causes of burnt circuit boards. To prevent burnt circuit boards, proper design, assembly, maintenance, and ventilation are necessary precautions.
Three of the main reasons PCBs end up burning are: Extreme heat. Improper component spacing. Component failure or technician error.
When to Consider Furnace Replacement. The furnace control board can last from five to 15 years, which means it can last the entire life of your heating unit. Too much dust and debris or extreme temperatures can shorten the component's life and can increase wear on your furnace.
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.
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.
Follow these simple steps: First, turn off the power supply to the furnace by turning off the breaker in the circuit box. 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.
Nevertheless, the damage can be repaired, and the board restored to its original integrity - and even appearance - by the following procedure. Some specialized tools are needed, and the liquid epoxy repair material can even be colored with color agents to replicate the color of the surrounding original board material.
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.
Power Component Failure. (Includes transformers, transistors, IGBT modules, rectifiers). Causes of failure: heat, over or under voltage, normal component aging. Some problems can be visible such as exploded components, or, more often, they could look perfectly good and require meter testing of each component.
Loose Wires
Wires can loosen over time due to the natural vibrations of a working furnace. If a wire becomes loose, it can short out, causing the fuse to blow. Because locating and fixing the loose wire can be a difficult task on your own, it's important to contact HVAC professionals for help.
In most newer systems, the button is often directly next to the blower motor, while in older systems, it may be harder to spot as it is sometimes underneath or behind the motor. The reset button is often made of yellow or red plastic and marked with a large “R ” to make it easier to spot.
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.
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.
The Average Furnace Lifespan
A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.
The older your furnace, the more vulnerable it is to malfunctions. Time takes a toll on any appliance, and as the years pass, vibrations, thermal expansion, power fluctuations, and general wear and tear can cause the furnace circuit board to fail.
If the control board gets wet, it may fail. How long does a control board last on a furnace? The control board on a furnace should last about 15 to 20 years, which is the typical life span of a furnace. However, certain parts of the control board can fail early, or a power surge can damage the system.
Consumer unit upgrade can take from 3 to 6 hours on average,
It is not until a site Survey has been carried out that the full extent of time can be allocated for the job.
In total, homeowners can expect the overall cost of replacing a furnace control board to be anywhere from $225 to $1,300, with most homeowners paying between $500 and $800.