# High Pressure Cutout



## Link (12 mo ago)

Hello, I am trying to troubleshoot my heat pump. I am not getting 24 Volts to my contactor. I have verified that I have the 24 v signal coming from my thermostat. When I checked the high pressure cutout switch on ohms it is open. What would cause this switch to stay open?

Thank you.


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## Steven123cool (Mar 2, 2021)

You have to have reversing valve (black) depending on O/B default) which is default position of the reversing valve)heat or cool and connect according to a heatpump stat. , heat (white), compressor(yellow), fan (green) energized for a heat pump to operate proper. Forget about your high pressure limit switch cause you don’t even have a call for it to be in affect. Make sure you have opened the valves to release the freon after you pull 500 micron vacuum. That will definitely keep your high pressure switch open. Obviously you don’t do this for a living and have tried to install a heatpump at home. You missed the basics on Heatpump control. Google it


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## Steven123cool (Mar 2, 2021)

Or the wire to contacting is broken take your wires off at both ends ans twist them into pairs with as wire nut, noting what color is with what color. At the other end stop the ends of all wires and ohm the pairs with tone(beep) signal on your meter. Then test ohms to each other wire in the bunch to see if it shorted to one of the colors you did not pair it with. Now a beep on the pair is good; wires are both intact end to end , however they may also be shorted to a other Color, so whe homing to nonpairs you don’t want a beep and if you get one the someone probobly put a stew or something through your stay wire . Further more to run a heat pump with all functions you must have at least R-24V, Blue-common to the 24V, Yellow- compressor, Green-fan, White-heat , and usually Black-reversing valve(position of default is necessary or just try it on cool and heat and see what you get, most are default position of reversing valve to heat, but not always.) and finally anc not always Orange Brown whatever you want for emergency heat runs to either a electric coil heater or to a gas furnace heat call. During operation of a heat pump the out door unit has defrost mode and or should something go wrong with the heat pump the back up will kick in during these time so you don’t freeze to death.


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