AC not cold, high pressure line cool to the touch

I am having an issue with my AC where it appears that my system is just pulling in the ambient air from outside. When I first turn my unit on I notice that the suction (big) line gets cold like it is supposed to and the high pressure line (little) gets hot as I would expect. I was able to confirm that on initial startup the compressor does start. However I am not quite sure how to confirm that it continues to run. The fan in the outside condenser runs and the capacitor tests fine. However, running after for around an hour or so I notice that the vents in the house seem to be luke warm. A digital thermometer on the vents shows that the temp coming in is within a degree or so of the outside temp (73F+). This system worked fine last year.

1. Could this be a sign of low refrigerant?
2. How do I test the compressor running after some time? I do confirm that disconnecting the fan and turning unit on that the compressor starts without any noticeable noise that would indicate to me the compressor is frozen. Is there a way to test the compressor after running for awhile?
3. There should never be a case were the high-pressure line is luke-warm to the touch, right? I do confirm that the suction line is quite cold to the touch and even has consensation on it. Even if the unit runs for awhile or the outside temp gets cooler, the high-pressure line should always be hot, right?

I have an old Williamson electric heat pump (have the pump disconnected and only use the elements to heat) as well as an outside Williamson condenser as well.

Thoughts or comments?

Thanks in advance.

 

Checking several times I still find the suction line is cold and even has condensation on it while the high-pressure line is not hot. Is it a function of the outside/inside temp that determines how warm my high-pressure line gets? Maybe it is warm, but not warm enough to make my high-pressure line as hot as I "think" it should be?

 

You dont say how hot it is outside????? That has a lot to do with it. Is the air filter clean and new?? A tech has to put gauges on to tell how the charge is . The small line mild, to warm to hot in the hot summer. The big copper line cold and wet by the outdoor unit

 

Well, I have run it at different times. To be quite honest I can't say that I have paid attention when it was running normally (ie last year) how it ran vs the temp. That does make sense to me though. I can say the temp has ranged from around 70's to lower 40's. It does make sense that outside temp matters. I seem to "remember" that it ran so the high-pressure was hot and the suction was cold, but I can not honestly say I paid attention to the weather. The suction is quite cold has condensation at the outside unit as well as the inside coils. The temp of the high-pressure line is the same inside and out as well. I know you'd have to put gauges on it to test the freon. If it were low on freon I'd expect that it would cause the coil to freeze up, especially as the outside ambient temp got colder. However I have not seen that yet (not sure if that is a hard/cold fact low freon always causes the coil to freeze.) So are you saying maybe I should have someone check the freon level and wait until it is a little warmer?

 

Id say get a tech to look at it . You need gauges put on it to tell anything for sure. Why is the H/P cut off????Sure cost less to heat.

 

Not sure what you mean cut off. However I can get a friend to check the pressure and freon and provide an update here.

 

Well, end of a legacy. The aluminum fan blades on the motor ended up getting a hairline stress break and one blade tore off which ended up making the system off ballance and cracked an aged piece of copper when it started walking on the platform before the broken blade ended up wrapping around the shroud and burned up the motor. Whew! Ended up replacing the old 34 year old Williamson heat pump system with a new Goodman air handler/condenser. It works like a champ now! The electric meter does not spin like a wild top anymore when it is running and the thing runs COLD. Anyway, I did have a tech put gauges on the old one. Said the levels were fine before the blade fiasco happened. I guess I will never know what really was going wrong with the old system. Thanks to everyone who provided suggestions and ideas to help troubleshoot.