High pressure occurs when the needle valve gets partially stuck open and goes directly into the compressor's crankcase. This causes both high low-side pressures and low high-side pressures. You should closely monitor whether or not the oil return line is above or below the ambient surrounding temperature.
How do you fix high discharge pressure?
One of the causes that have been established in relation to high compressor discharge pressure is the presence of air in the system. When this takes place, your best solution is to recharge the system. Another is a clogged condenser in which case you will need to clean the condenser so that it will function properly.
What should high side AC pressure be?
Ambient Temperature (°F) Low Side High Side
------------------------ --------- -----------
90° 50-55 psi 250-275 psi
85° 50-55 psi 220-250 psi
80° 45-50 psi 175-220 psi
75° 40-45 psi 150-175 psi
What does high head pressure mean in HVAC?
Overcharging of refrigerant, liquid slugging of the compressor, oil contamination and other sources can damage compressor valves. Refrigerant overcharging will show up as high head pressure, normal suction line pressure, normal superheat, high sub-cooling.
What causes high pressure in HVAC system?
Three causes of high static pressure in ductwork are: Air Filter is Clogged or Too Restrictive. The Air Returns are Undersized. Indoor Coil is Dirty or Too Small.Oct 16, 2019
Can too much refrigerant cause high head pressure?
Liquid backed up in the condenser from the overcharge of refrigerant will flood some of the condenser's internal volume at its bottom, causing high head pressures.Aug 6, 2018
What should AC high side pressure be?
The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. If the ambient temperature is higher or lower than normal (70 to 80°F) the pressures will go up or down accordingly.Jan 25, 2019
Why is my high side AC pressure too high?
Higher than normal air pressure is usually a consequence of two situations. One, your AC system might be facing limited or no airflow through the condenser. This, in turn, might be a consequence of bad condenser fan motor. ... Second, the other reason for a high-pressure reading can be an overcharged system.
What can cause excessively high discharge pressures on an air conditioning system?
One common cause of high discharge pressure is the cooling medium (air or water) flowing across the condenser: either there is not enough or the temperature of the cooling medium is too high. This is normally easy to identify with a simple visual inspection of the condenser.Mar 9, 2020