mystery switch

[mjmchal]

I have a carrier heat pump just 3 weeks out of warantee when condenser fan quits. I had carrier service come in and they said I need new fan. Being the sceptic I am I run fan to 220 and it spins like new. I suspect real problem is vapor pressure switch on low side that controls on/off of fan during heat and cool usage. My question is if this switch is screw on with schrader valve or some kind of clamp on unit that would entail evacuation of system. I don't want to do something that wuld dump all my refrigerant. Surely Carrier wouldn't design it so you have to evacuate for a switch would they?
I have been running the air for a week with the jumper and the system is running great so I really believe the only problem is the pressure switch.
Any advice appreciated. :confused:

[scottg]

Yes most pressure switches are screwed on the system with a 1/4'' fitting that has a valve core.
What I have found is if I cut the wires as short as possible then it is easier to remove quickly, this assures the least amount of refrigerant leakage. You should also use two wrenches one to hold the fitting and the other to hold the switch.

You might even make use of the service valves to pump down the refrigerant in that tube.

Installation is easier to perform when you twist the wires first in the opposite direction then screw it back on. You also put a wrap of teflon tape on the fitting to aid in the ease of screwing it back on.

[Grady]

Very few factory installed pressure switches screw on. Most are brazed to a capillary tube. When I have a bad one, I add a swivel tee to the schrader & install a screw on switch.