High Pressure Re-set Button

[Greg Jenkins]

Is anyone familiar with the high pressure re-set button located on Rheem heat pumps. The button is located at the exterior unit. Twice in the last week I have encountered rheem heat pumps. Both times, the button needed to be pushed in order to get the units to operate in A/C mode. When I tested the heat pumps, I operated them in heating mode in the morning (and they functioned) while the exterior temp. was still cool and then waited till mid morning to operate in a/c mode when outside temp began to rise. Here in WV this time of year we get cool mornings - 50's and then it quickly gets into the 70's. Both units were approx. 10 years old.

[Jim Luttrall]

I am not familiar with those particular units, but are you sure that it was a reset and not a service override to bypass either the timer or the ambient temperature lockout? Just thinking out loud here.
Jim

[Jerry Peck]

As I recall, some units do have a reset button, however, there is no good reason for an HI to have to reset it ... it should not be popped off, and, if it was popped off, it needs to be serviced and checked by a "competent" HVAC person.

[Greg Jenkins]

The switch is located at the bottom edge of the compressor housing. It is a big red button that is labeled High pressure re-set button. It almost seems that rheem knows there is a problem and places this re-set button in plain view. When I first encountered the button last week, the home owner pushed the button and said "Oh - if you mess with the thermostat too much, sometimes you have to go and press the re-set button." On my second encounter with the same compressor (different house), I switched the thermostate to a/c and it did not respond. So I pushed the re-set button out of curiosity and the compressor started. I am with Jerry, you should not have to press re-set buttons to get your equipment to operated. I have called both units out for service. Incidentally, the during the last encounter the home had two rheem heat pumps. Both had re-set buttons but only one needed re-set. The other unit operated in both modes without having to push the button. Also, I have read some other posts regarding the condition and some have indicated it could be because of low refrigerant, low air flow, and or a failing compressor.

[Jim Luttrall]

It is a big red button that is labeled High pressure re-set button.

I guess you are right, it must be a high pressure reset button:D

High head resets are like breakers in that they are not supposed to trip during normal operation. I am with you and Jerry on this, if it requires resetting, the unit needs service.



Also, I have read some other posts regarding the condition and some have indicated it could be because of low refrigerant, low air flow, and or a failing compressor.


Low refrigerant or a failing compressor won't cause a high head condition.
Low air flow due to a failing condenser fan or a blocked condenser would be the main causes.
Don't forget that in heating mode, the indoor coil becomes the condenser, so a dirty filter, blocked return or supply grills, etc. could cause a high head, especially on a warmer day.