I have the correct Manifold Gauges for checking the low and high side of the heat pump. How do I read the gauges to ensure that my system has the right charge? Outside ambient temperature is 85.4.

My suction pressure was 65 and my pressure side or high side was at 113 psi. Does this make sense to you? My suction pressure was 65 and my pressure side or high side was at 113 psi. Does this make sense to you?

Those pressures seem way too low, is the unit cooling? Those pressures seem way too low, is the unit cooling?

Measure the subooling and we can figurenout whats going on with your unit. Measure the subooling and we can figurenout whats going on with your unit.

Here is the latest on my Rheem system. The outside ambient temperature was 95 degrees F. The high side gauge read 120 psi which corresponded to a saturation temp of 106 degrees F. The temperature of the liquid line was 112.1. Subtracting the two will give me a 6.1 degree subcooling. My back panel has a chart that has outside temperature in a column on the left and I assume pressures going across the top. Not sure how to read it. Here is the latest on my Rheem system. The outside ambient temperature was 95 degrees F. The high side gauge read 120 psi which corresponded to a saturation temp of 106 degrees F. The temperature of the liquid line was 112.1. Subtracting the two will give me a 6.1 degree subcooling. My back panel has a chart that has outside temperature in a column on the left and I assume pressures going across the top. Not sure how to read it.

Does the panel chart tell you what the subcooling should be, usually it will be eithet 10 degrees, 12 degrees or 15 degrees of subcooling. Based on the info you gave me it sounds like your unit is undercharged. With a 95 degree ambiant your head pressure should be around 250 psig not 120. The way you read that chart is take your pressure and your temp and where they intersect it will give you subcooling. However, most manufactures will have subcooling as 10, 12, or 15 degrees. But if it has the chart use it to find proper subcooling Does the panel chart tell you what the subcooling should be, usually it will be eithet 10 degrees, 12 degrees or 15 degrees of subcooling. Based on the info you gave me it sounds like your unit is undercharged. With a 95 degree ambiant your head pressure should be around 250 psig not 120. The way you read that chart is take your pressure and your temp and where they intersect it will give you subcooling. However, most manufactures will have subcooling as 10, 12, or 15 degrees. But if it has the chart use it to find proper subcooling

Have you tried to add refrigerant to tne system? Have you tried to add refrigerant to tne system?

It has been nearly 21 years since I worked on R22 systems. The service ports where I have my gauges connected to have brass caps and a set screw or valve that can be adjusted with a standard flat tip screwdriver. I always remembered that these should be open unless you are isolating the heat pump, then they should be closed. This is correct right? It has been nearly 21 years since I worked on R22 systems. The service ports where I have my gauges connected to have brass caps and a set screw or valve that can be adjusted with a standard flat tip screwdriver. I always remembered that these should be open unless you are isolating the heat pump, then they should be closed. This is correct right?

That is correct, anytime you isolate the outdooor unit from the indoor unit the valves should be closed, or when you pump the refrigerant down into the condenser. Other than that they must be open. That is correct, anytime you isolate the outdooor unit from the indoor unit the valves should be closed, or when you pump the refrigerant down into the condenser. Other than that they must be open.

So you have 6 degrees of subcooling and your high side pressure is 120 psi, what is your low side pressure? So you have 6 degrees of subcooling and your high side pressure is 120 psi, what is your low side pressure?

Here is the latest. I am using the Yellow Jacket Manifold that can check R22, R12, R412 and R506. When I read the high side pressure at the top of the gauge, it says 240 psi but when I go down to where it says R22, it says 117. The low side says 63 on the gauge but reads 34 when you look at the R22 wheel. The outside ambient temperature is 92 and the vapor line temperature is 71 degrees F. Here is the latest. I am using the Yellow Jacket Manifold that can check R22, R12, R412 and R506. When I read the high side pressure at the top of the gauge, it says 240 psi but when I go down to where it says R22, it says 117. The low side says 63 on the gauge but reads 34 when you look at the R22 wheel. The outside ambient temperature is 92 and the vapor line temperature is 71 degrees F.

Ok the high side pressure is where it should be, the low side pressure is too low, with a normal high side pressure and a low suction pressure with low subcooling it looks like you may hav noncondensables in the system such as air or a liquid line restriction.. I would recover the refrigerant, pull a vacuum on the unit, and then weigh in the refrigerant charge to what the unit holds Ok the high side pressure is where it should be, the low side pressure is too low, with a normal high side pressure and a low suction pressure with low subcooling it looks like you may hav noncondensables in the system such as air or a liquid line restriction.. I would recover the refrigerant, pull a vacuum on the unit, and then weigh in the refrigerant charge to what the unit holds

Thanks for the information. I hope that i have enough R22 to charge the system. All I have left is about 20 lbs of refrigerant. I was having a hard time reading these new gauges as they are not the same type I used years ago. We use to use just the gauge line for the refrigerant that we used. Apparently not the cause now days. Thanks for the information. I hope that i have enough R22 to charge the system. All I have left is about 20 lbs of refrigerant. I was having a hard time reading these new gauges as they are not the same type I used years ago. We use to use just the gauge line for the refrigerant that we used. Apparently not the cause now days.

Yeah i hear you, things keep changing in the hvac industry. Now r410a will be the new refrigerant instead of r-22. Yeah i hear you, things keep changing in the hvac industry. Now r410a will be the new refrigerant instead of r-22.

It does not change it very much, with a fixed orifice metering device you need to know the indooR wet bulb temp, outdoor dry bulb temp to find the proper pressure. It does not change it very much, with a fixed orifice metering device you need to know the indooR wet bulb temp, outdoor dry bulb temp to find the proper pressure.

No problem, do you need anymore help? No problem, do you need anymore help?

That low side pressure is too low for tne conditions, i would suspect a low charge That low side pressure is too low for tne conditions, i would suspect a low charge

But since the high side pressure apperars normal, this would indicate a restriction in the system to me But since the high side pressure apperars normal, this would indicate a restriction in the system to me

Add some freon and see if the low side comes up a little but watch the high side pressuresomit does not get too high. Let me know Add some freon and see if the low side comes up a little but watch the high side pressuresomit does not get too high. Let me know

Try to get it to about 70 and then see if it holds for about a half an hour Try to get it to about 70 and then see if it holds for about a half an hour