A furnace is an essential part of your comfort at home. They are intricate machines with many essential components that guarantee maximum output and protection. Without a furnace, you would be left to freeze when the weather gets cold. Playing a crucial role in protecting the safety and effectiveness of any heating system is the furnace pressure switch. So, it is important to check on this safety feature constantly. To help you understand why this part is so significant, here is a deeper look into what it does and when it needs furnace servicing. 

What Is the Purpose of a Furnace Pressure Switch?

Found near the motor, this device is designed to prevent the furnace from working when there is not enough pressure in the heating system. This switch turns the furnace off when it detects negative pressure caused by the draft inducer motor. When there is too little or too much pressure in the system, the switch will again turn off the furnace to prevent damage to the heating system or other appliances. Also, this device prevents gas leaks and stops the furnace from cycling in case of a mechanical malfunction.

Pressure Switch and Furnace Technology

The configuration of this component depends on the technology the furnace uses: conventional or condensing.

Single-Stage Conventional Furnace: A single-stage conventional furnace typically has only one hose that runs from the draft inducer fan to the pressure switch.


Single-Stage Condensing Furnace: The pressure switch for single-stage condensing furnaces typically contains two hoses: one to register the pressure created by the draft inducer and another to detect the venting pressure at the condensate collector box.

Two-Stage Furnace: It is common for a two-stage furnace to have dual pressure switches. It is because each of the system’s two heat exchangers needs its own switch to function properly.

Common Problems

Identifying an issue is not always easy, but some common issues can keep the system from turning on. 

Detached or loose hoses: While connected on both sides, the pressure switch relies on firmly attached hoses. Should either end go loose, then it will not be able to close, and your furnace will not turn on. An experienced HVAC technician can securely reattach them for you.

The build-up of dirt and dust on the switch: Dust or other particles collecting in or on the switch can hamper its performance, eventually causing rust and corrosion. Regularly clearing away these obstructions should be a priority to maintain the switch’s optimal performance.


Worn-out hoses or tubes: When tubes or hoses become worn down, they weaken and result in cracks or holes. That can lower the pressure in the pressure switch, making it hard to work properly. In this instance, it is best to contact an HVAC specialist who can replace both tubes, as they likely have deteriorated over time.

Malfunctioning furnace switch: Another component in the furnace may damage the furnace switch. An instance of this could be a blockage in the inducer fan, which can destroy the switch and require it to be replaced.

Never Ignore Long-Term Furnace Pressure Switch Issues

When there is an issue with the pressure switch, your furnace may not turn on or operate at its best. Even worse, long-term issues with a pressure switch in a gas furnace can result in lockout mode. That means the furnace remains off despite any attempts to fix the switch. So to get back up and running, you must completely replace the pressure switch and reset the furnace. Fortunately, your HVAC technician can easily assist with this lockout problem.

Furnace Repair Near Me

When the weather turns colder, it is time to switch the furnace to heating mode. But what can you do if your furnace is not doing what it should? Here at Pioneers Heating and Air, your comfort is our top priority. That is why we offer 24-hour emergency furnace repair when you need it most. Pioneers Heating and Air is a BBB-rated furnace repair company with over ten years of industry experience. We are experts in furnace pressure switch repairs and servicing. Our team of technicians can perform any heating repairs. We offer a 100% satisfaction guarantee on all our work and are always available to answer any queries. So give us a call today to learn more!

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