what happens when a furnace pressure switch goes bad

What Happens When a Furnace Pressure Switch Goes Bad?

A pressure switch works with electricity the way a dam works with water. If the dam is open, water can flow freely. If the dam is closed, it prevents water from moving.

Likewise, when the pressure switch is open, electricity can flow through. When the pressure switch is closed, it stops the flow of electricity. So what happens when a furnace pressure switch goes bad?

If you suspect your furnace pressure switch is faulty, you need professional furnace repair from Tucson’s HVAC company. Our technicians at Eazy Breezy Heating & Cooling in Tucson, Arizona, are available to diagnose any furnace problems. Call us at 520-207-0334 to schedule reliable service in Tuscon, AZ.

Signs of a Bad Pressure Switch 

The furnace pressure switch is a safety device that makes sure your furnace is working properly. The signs of a bad furnace pressure switch can be pretty obvious.

When you know what to look for, it’s easy to see what happens when a furnace pressure switch goes bad. If you notice any of the following, you could have a furnace issue on your hands:

An Unexpected Light Show

If you think the pressure switch has gone bad, take a look inside your furnace. If you see a pulsing light inside that you have never seen before, that is a signal to you from the circuit board that there is a problem. 

Cool Air Only

A lack of hot air blowing through the vents is probably your first clue that your furnace is experiencing mechanical failure. If you keep bumping up the temperature, but your house is not getting any warmer, that is a major cause for concern.

Total Decline

Your furnace may shut off unexpectedly and then decline into not functioning at all. If this happens, schedule a professional to inspect your unit. Older furnace models have different levels of efficiency than newer furnace models. 

Common Causes of Furnace Pressure Switch Failure

Furnace problems are bound to happen eventually. A handful of issues could contribute to a bad pressure switch. 

Older Parts

With regular furnace maintenance, a pressure switch typically has a life of about 15 years, but none of them last forever. If your furnace pressure switch is older than the family dog, it will begin showing signs of age and likely need a replacement soon. 

Normal Wear and Tear

Regular use over the cold season and throughout the years takes a toll on your furnace. A trained HVAC technician can examine the pressure switch and detect cracks and other damage caused by normal use.


During your annual cleaning appointment, your HVAC professional will fully clean the inside of your furnace. Doing so prevents dirt from hindering the functionality of the pressure switch. 

Let the Experts Help

What happens when a furnace pressure switch goes bad? In short, the entire furnace suffers, necessitating professional service.

Repair costs and efficiency levels vary when it comes to gas vs. electric furnaces. Whether you need yearly maintenance, a quick repair, or a total replacement, call 520-207-0334 to schedule an appointment in the Tucson, Arizona, area with the experts at Eazy Breezy Heating & Cooling.

Contact Us

Eazy Breezy Heating and Cooling can provide you with regular tune-ups for both your furnace and air conditioner in your Tucson home. We’re professionals, so we’ll always provide you with the best service possible. Don’t wait another day before getting the routine maintenance you need–call us today!

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3710 S Park Ave #705
Tucson, AZ 85713

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