My york heat pump keeps kicking out on high discharge temp. That's what the code on the outside unit says. Any help with this issue? What can I do to fix this issue ? I do have some skills in heating and A/C

Check the following.

Unit overcharged.

Defective sensor for detecting high temperature.

Dirty air filter inside.

Blower motor not operating at proper speed inside not allowing the removal of heat from the heat pump.

Electric heaters stuck on when heat pump in operation causing lower than needed heat removal from the outside heat pump unit. (some systems)

These are just a few ideas.

You will need pressure gauges and a quality temperature meter for testing purposes. Naturally you will also need the skill to operate the test equipment and be able to what the test equipment is telling you about your system.

HVAC 1000 IS absolutely right it could be any nuber of things but first thing you need to check is the actual pressue itself and the temperature to verify you are getting an accurate code reading. You can use a p/t chart to verify your pressure and temp. The most common thing people seem to over look is a dirty air filter or dirty indoor coil from a dirty filter which would give you a low suction pressure in cooling mode high in heating mode. Also a dirty condenser coil can cause high head pressure in the cooling mode you can tell this if the liquid line is extremely hot and the discharge air of the condenser is extremely hotter than normal. This would be in the cooling mode. Also in cooling mode a normal head pressure and low suction could be a bad txv

Thanks guys I did check the pressures and they seem to be fine, the suction line temp was at 135 and the suction pressure was at 40 couple today it was in the 40's checked the filter and it is clean the coil looked clean as well. I guess the next step may be the TXV. I did not check the head pressure, and I may just get some coil cleaner and run that over it. It almost seems that it might be something when it goes into defrost as well.

Guess the next step may be the TXV

This would be the last item I would mess with.

Is it a temp act switch or a thermistor on the discharge line? The pressures you gave are not high so it should not be kicking out on high temp. If you have a restriction at your txv or a bad power head it would be bad all the time not just some times.

I believe that it just has a strap on temp switch

Its just a stab in the dark but I would say you have a bad temp act switch. One thing that could cause it to trip is if the defrost board or defrost thermostat did not terminate defrost. The heat pump would stay in cooling mode with out the condenser fan running and that would make the hot gas temp switch trip. You can short out the test pins on the heatpump to make it go into defrost mode to see if it will take its self out.

The board on this unit is one of those " york guard IV " boards I didn't take notice to any test pins on this particular board.