Luxaire furnaces come with numerous components that ensure precise operation and reliability. The pressure switch is one of these features that makes sure that the gases produced during the combustion process will go out of your home and don’t come back into the system. If otherwise, a complicated process, “Back drafting,” will develop, requiring immediate servicing.
Back drafting can make the harmful gases generated by the combustion process (carbon monoxide is the most common name) to go back into your house’s air supply. Back drafting may lead to tiny explosions in the heat exchanger, which is the most crucial component of your Luxaire furnace.
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How does the pressure switch prevent back drafting?
The furnace will generate gases throughout the heating process, and some of the gases are poisonous. The draft inducer motor will collect the gases from the heat exchanger and away from the house through a flue pipe.
The pressure switch controls the draft inducer, making sure that it’s correctly eliminating the gases. When the draft inducer works correctly, the pressure switch closes to end the circuit (or “turn on”).
When something is wrong with the draft inducer motor, the pressure switch will open (turn off), switching off the furnace, so it doesn’t allow ignition.
There’s an excellent side to the pressure switch remaining open, as it means that it protects the furnace from operating and preventing harmful gases get inside your house.
Luxaire furnaces will display code 2, 3, or 6 when something is wrong with the pressure switch. Even if the error code is signaling that the pressure switch is stuck open or remains open, most of the time, there’s not a problem with the pressure switch but with another component that is malfunctioning.
How should you check the pressure switch?
You will have to remove the primary access panel and examine the hoses attached to the furnace pressure switch. These hoses should look fine, without any obstructions, and attached at both ends.
Should some of the hoses be loose, you need to reconnect them. Eliminate debris, replacing all cracked hoses. You or your HVAC technician will have to replace the pressure switch if the hose ports (where the hoses connect to the switch) present cracking.
How much will you pay for replacing the pressure switch?
Should you decide to replace the pressure switch, you will pay anything from $14 to $50 for a replacement.
If you consider you don’t have the skills, knowledge, and equipment for replacing the pressure switch, it’s wiser to call the HVAC technician. It will cost you from $80 to $200, depending on the area where you live and the time of the service call.
Why does the pressure switch remain stuck open?
The pressure switch may remain stuck open for various reasons, but the most important are as follows:
Detached/damaged pressure switch hose
The pressure switch can inform the system that the inducer motor is appropriately functioning with a hose. When this hose is damaged in any way (holes, cracks) or detached, the pressure switch will obtain an imprecise reading and get stuck open.
Damaged/disconnected hose is a problem to identify and address on your own, but it’s always wiser to call the HVAC technician for accurate fixing. It’s relatively straightforward to see if the pressure switch hose is detached from the inducer draft blower, but putting it back together is more challenging.
When the hose is damaged for good, the HVAC will have all the tools and skills for replacing it.
Blocked venting
When the furnace’s flue pipe is obstructed, the system will not eliminate the combustion gases, causing the pressure switch to remain open.
It’s relatively common for the flue pipe to clog, as leaves, feathers, dirt, debris, or anything similar are typical around houses. The flue pipe can also freeze, or snow and ice may clog it in the winter.
You may easily observe the furnace’s venting by examining the flue pipe. If you have a conventional furnace, the flue pipe should be on the roof. High energy-efficient furnaces come with PVC pipes that are typically placed on the side of your house.
If you spot debris and it’s easy to reach it, you may get rid of it; turn the furnace back on and see what happens. When removing the clogging doesn’t solve the problem, you should call the HVAC technician. A clog may still be the cause, but it could be farther down in the system, stopping the furnace from eliminating the combustion gases.
The pressure switch is defective.
When you don’t observe anything blocking the flue pipe, and you know for sure that the pressure switch hose is still attached, the pressure switch could be, in fact, the problem.
You will have to call the HVAC professional; he will use a digital multimeter for testing the switch, replacing it if required.
Testing and replacing the pressure switch isn’t the most complicated job to do for the furnace, but it still requires knowledge, skills, and proper tools. If you don’t install the pressure switch correctly, the furnace will suffer damage in time and even pose a risk for your family’s safety and house.
A pressure switch stuck open doesn’t make the most severe problem that your Luxaire furnace could develop, but it’s always wiser to call the HVAC technician for repairs and servicing. Why take any chances when you and your family’s health and safety are at stake?
