iced the eveporator coil

[comfortable air]

a customer call no ac.when i got to the customer house, I found the evaperoter totally iced. defrost the ice. it is a heat pump. I hooked the gage. the low side is only 40 psig, more than 40 supreheating.high side 220 psig, the subcooling is almost 0( Maybe I measureed not accurate). is it undercharge or capilary tube restricted?

[Edited by comfortable air on 07-12-2005 at 07:39 PM]

[Special Ed]

Dude, aren't you a tech? Sounds like it's low to me but I don't know what the ambients are. Could be possible the RV isn't fully switching over to cool either.

[comfortable air]

Yes. I am. but it is my first time to servie the heat pump.
ambiet temperature is more than 90f. I don't think rv is not fully open for cooling. it either open or close. it could not be partly open.

[Hroper]

Did you check the filter, Indoor coil, return air or make sure the blower motor is running? Might as well try a shot of r22.

[beenthere]

With no subcooling, and high superheat it sounds like a leak.

Check for a leak.

Fix the leak, and recharge it.

Yes, I omitted acouple steps.

[docholiday]

Originally posted by special ed
Could be possible the RV isn't fully switching over to cool either.

With a 40 suction?

OP...

You are working on a heat pump in cooling mode. Why would this be any different than a straight AC at this point? Use what you know about AC and dont get hung up on the fact its a heat pump.

[corny]

Dump a gallon of refrigerant into the system and see what happens..........

[comfortable air]

thank you everybody. the high pressure don't lookes like undercharge. when i met some 40 psig at low side, the high side usually don't over 200. I am sure it is undercharge. but this time is different. the head pressure is not low.
the evaperator coil and filte is ok. the air volume is also ok. I dump some of gas inside it to increase the head pressure. I will go back to see how is it going. if it is a leakage, the problem will be repeat soon

[Edited by comfortable air on 07-13-2005 at 11:07 PM]

[docholiday]

I'm curious but what exactly is ok air volume. Just so we stay on the same page here.