Air Conditioning - Replacement question if outside compressor shot

The A/C quit today on our 10 year old Rudd Seer 13 heat pump unit that cools/heats our 1206 sq ft ranch house.

I called for a service guy but it will probably take him a few days to get here. I'm hoping it's a simple problem, yea right, but I suspect the outside compressor is gone since it is making a funny sound.

If it is the compressor, someone said it would be better to replace the entire outside unit rather than have him just change the compressor. Is this right? Do you also have to replace the inside evapator coil which is located in the crawl space at the same time?

Thanks,
Jim

If it is in fact a 13 seer evaporator inside, no you dont have to replace it, however due to the fact that the unit is 10 years old, nearly at its end life of 12-15 years you might want to replace it too. That being said it is true only the outside condenser unit needs to be changed in your case. The minimum seer today is 13 seer required by law. If the inside evaporator turns out to be 10 seer or less, it will in fact not work properly and will have the capacity greatly reduced even with a new expansion valve. It can cause flooding of the evaporator and vapor line when charged with refrigerant to the proper pressures ( some have tried to do it and can only partially charge the system because of the mismatched units* Size matters) to avoid ruining the new compressor, but the capacity is once again greatly reduced and will not cool well.

If in fact you have a (13 seer) evaporator inside, and it does not have an expansion valve as a metering device, I recommend at least replaceing the existing metering device ( I think ruud/rheem heatpumps sometimes uses an orface type metering device which is far less effiecent).

Thanks for the quick reply. The evaporator unit is mounted in a horizontal configuration in the crawl space. I'll see if I can find a label on it today that indicates the Seer rating. Outside unit has a big 13 Seer stamped on it and I'm sure both were orginial when the house was built.

Late yesterday I did find that the drain pipe from the evaporator pan was plugged up so the evaporator pan was full of water. I cleared the line so it drains fine now.

The A/C seemed to work some last night. Outside compressor noise sounded more like it normally does. Maybe it's just doing that because it knows a service guy is coming. Like when you go to a doctor and things feel better while your there...

I went under the house to check the label on the evaporator unit. When I took the cover off, the coils were packed with ice. Does that indicate that the R22 is low from a leak somewhere?

Low Airflow (dirty filter-clogged evaporator/airflow blockage/blower motor problems) - Contactor frozen welded contacts, (closed on the condenser while the Airhandler is in the off cycle) - Or refrigerant leak (only for a small window in the stages of a leak will it cause Ice buildup) These are the most often causes of Ice buildup on evaporator.

Thanks for the ideas to check before the service tech gets here. Filter is new and air flow seems normal running in fan only mode. Blower seems to work as normal.

The contactor (which was changed 3 years ago) does have some pitting on the points but they are not stuck or appear to be sticky, in that the spring action works fine (with power off of course).