Head pressure high; suction pressure low. Unit not cooling

check for both fans running,,,,,, wash & clean condensor unit

That piston is the metering device. On the liquid line, before the metering device it is always warm (this is sub cooled, high pressure liquid), but should flash to low pressure, lower temperature vapor once it passes through the metering device. The suction and liquid line never connect together.The liquid line brings liquid from the condenser to the evaporator. The suction line brings super heated vapor from the evaporator to the compressor. Since the unit does run, I'd have to put a gauge on it,but if I had to guess, I'd guess you have high head pressure. Check for dirt or debris on the condenser, check for proper clearance of the condensing unit and check for operation and directional rotation of the condenser fan. This could also be the result of an over charge.

have you removeing the filter from the front of it sometimes colecting all that dust in it can cause it send only luke warm air out also if youve had it on none stop it can sometimes freeze but then letting it sit for a couple hours to a day usually solves that

That is a high suction pressure should be running about 46 psig and head pressure should be amibent temp or outside temp and add 25 to it. that will give you approximate head temp. sounds like you have a dirty condenser I would clean it. Check your amp draw on your compressor if its high then I would check for dirty condenser. You can clean it with a stiff hair brush go up and down do not go sideways because you can damage your fins on the coil. Then take a water hose and wash it out. turn off the power to the unit before cleaning do not clean with compressor running. turn off the breaker box. I hope this helps.

Hi, sounds as though for this to be its 2nd compressor for such a newer unit, the superheat was not right when the compressor was installed. I don't know what freon you are using the new R-410A or the regular R-22. There's a big difference in pressure, but now I see your pressure reading and its R-22 for these readings.For a 2 ton unit, you would use the superheat charging method for a unit that doesn't use a thermostatic expansion valve ( T X V ) and not the sub-cooling. A 23 degree super heat at that outdoor ambient temperature is way to high for that unit, you will loose the compressor again!!. Super heat killed the compressor is the saying and that's a fact. Suction pressure should pull down just as quick as the head pressure unless the valves are going and weak, or you have a scroll compressor that has a valve plate that is going, or you are low on charge. With a ambient of 95*, you should be at around 270p.s.i. on your head pressure as 210 to 200 is way low. Suction line temp should be around 68 to 70, with a suction line temperature of 50 to 51 degrees, which would give you a 10 to 12 degree F super heat. I don't know when the second compressor was installed, but it has to be low on charge to be such a low head, and high super heat and you will loose this compressor again, its only a matter of time before you have a burnout. It was either under charged when installed, or has a very small leak at one of the joints. I hope the liquid line drier was replaced also. It shows me you have some knowledge on a/c operation, so you need to get that superheat down to between 8 and 10 degrees for this unit to cool properly, and leak check it also. Did you buy a extended compressor warranty? Lets get the head pressure up and superheat down and you should be OK unless the valves or valve plate is weak. Once you loose the valves, you will have a lower than normal head pressure and a high suction pressure. Compressor just won't pull down anymore. I hope I have been of help to you and ask of you to be kind when rating me. I will be here for you if and when you need me for anything.
Sincerely,
Shastalaker7
A/C & Heating Contractor

Make sure the outside fan is running. Also check the high side pressure, I assume the 70# is the low side pressure, so you can tell what the compressor is doing. If the fan and compressor are both working, make sure there is good airflow through outdoor coil and check that it is clean. Let me know what you find.

Hi, High head and a low suction pressure can indicate a couple of different things. One, condenser coil very dirty and needs to be washed very well. This will bring your head pressure down but let it run back up to normal engine temperatures. If the head is ok after you clean it, and suction is even lower, you may still be low on charge. If the system is over charged will cause this problem. You may want to clean coil, evacuate unit, and weight in your charge. Charge is critical on a auto a/c. You may also have a restriction in the filter drier or site glass. Go through the basics first. Suction should run about 18 p.s.i. Head will run about 27*F over ambient.If you are running R-12 or 134-A, the pressures will be close on your gauges. Go by your scale on the inner part of your gauge which is temperature. So, for R-12 with an outdoor temp of 90 degrees, your head will be about 150 p. s. i. Remember, the charge is critical. Good luck,
Shastalaker7

try cleaning a-coil

These numbers are a little high depsite the high ambient conditions.Amazingly enough ,automotive low side suction pressure will equal the degrees its putting out at the evaporator coil...for instance,70 psi low side pressure will produce about 70 degrees of cooling. At 300 psi on the high side(which is high) this is about as low as the suction pressure will go....you need it to go lower.I would probably be concerned with the freon level as a slight overcharge could boost these numbers.Poor air flow through the condenser can also create a higher head pressure than desired.If possible,I would evacuate and re-charge the system with the correct amount of 134a refrigerant. Try to get those pressures lower...about 250/50 would be a decent pressure value in this ambient condition.Verify good airflow through the coils and pay close attention to any foreign debris like plastic grocery bags or wrappers covering the coils...Ive even seen these make their way between the small gap between the condenser and radiator so use a light and inspect carefully for this.Air flow through that condenser coil is vital and any deficit there will create high head pressure which obviously causes high suction pressures....good luck

I have to know what the outside temp is and I also need to know the seer of the unit. It would also help to know what the indoor temp is as well. Generally your suction pressure or what you are referring to as the indoor temp will be about the same. Let's say your indoor temp is 75, then your suction pressure should be around 75psi as well. Based on the suction pressure you just gave me, I would bet that the temp is not 38 degrees. With the suction at 38 and a low head or high side, you may be low on refrigerant. 110 is a little low but again, this depends on the seer rating of the unit. A higher seer will have a lower head.