Where’s The Reset Button On My Carrier Heat Pump Or AC Unit?


It’s a huge temptation to push that button, if you find one. You’ll notice in my images that some pressure switches have buttons and others don’t. The pressure switches that have no buttons are automatic.

They reset themselves if the pressures fall within the parameters of the pressure switches design. The pressures vary according to the engineering of the equipment.

But wait, wouldn’t you like to know why that button popped off? Should you be concerned that by pushing that button (if you find a button) one more time that you might be causing damage to your very expensive system?

Why Do Pressure Switches Pop?

The number one reason for a reset button to shut down your system is high head pressure. High head pressure can only be determined by a service technician with gauges that will measure the pressures in your AC unit. Pushing that button could repeat the problem and just cause the button to pop off again.

High head pressures cause the compressor to run hot. Sort of like running your car low on antifreeze. A hot compressor means the oil in the compressor can over heat producing harmful acids and contaminates in the sealed system that contains the refrigerant (Freon) and oil.

What’s A Pressure Switch Look Like?

I’ve pushed a lot of reset buttons, but I’ve done that with gauges connected and knew immediately what the problem was before further damage was done. You can recognize them by the small red (usually red) button on one end and a small copper line on the other that connects to the sealed system and senses the pressure.

Also a couple of wires that will open a electrical circuit to shut the unit off. The button will not always protrude to the outside of the unit as you see in the image below. It may be down inside.

Be Safe And Don’t Damage Your Heat Pump

I watched a YouTube video of a guy poking a stick down inside a unit through the fan to reset the button. I don’t think that’s advisable. So the unit starts and you can’t pull the stick out fast enough. Maybe a chopped stick or bent fan blade.

I have to tell you this before we get too deep into this topic. Very few heat pumps and air conditioners actually have a reset button. They generally have either a auto reset high pressure and or an auto reset low pressure switch. These switches can sometimes cycle a unit until the problem gets serious enough that the unit shuts down completely. Not the best solution but better than nothing.

So if you must, go ahead and push that button. But I’d only do it once.

Chad Peterson

Chad Peterson is near 40 year veteran of the HVAC industry. "I like to explain heating and air conditioning problems in a way the average home owner can understand. "

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