Asked by: Mahayuba Onça
home and garden indoor environmental quality

What would cause excessive pressure on the high side of an A C system?

Last Updated: 25th February, 2020

Overcharging of the system is usually caused due to an excess of refrigerant in the system. It can also be because of excess oil in the system. To test for an overcharge system, you would need to measure the pressure of the system.

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Simply so, what should high side AC pressure be?

The low-side should be near 30 PSI at 90 degrees Fahrenheit or less. Pressure that is too much lower or higher shows there is a problem. On a properly working system, high-side pressure will be about twice the ambient temperature, plus 50 PSI.

Similarly, what should the gauges read on 134a? For a low pressure gauge, a reading of 25 pounds per square inch (psi)to 40 psi is optimum. On the other hand, a high pressure gauge should read between 225 psi and 250 psi.

Correspondingly, what are the symptoms of an overcharged AC system?

In summary, there are seven symptoms or telltale signs of a system that has too much refrigerant.

  • High discharge temp.
  • High subcooling in the condenser.
  • High pressures in the condenser.
  • Higher condenser splits.
  • Normal-to-high evaporator pressures.
  • Normal superheats.
  • High compression ratio.

Which is high side low side on AC?

The high side, or discharge line, will be the line connected to the compressor from the bottom or lower position. It will not be wrapped in insulation and will be warm to the touch. This is where freon exits the compressor as a liquid.

Related Question Answers

Codi Petzschke


What is a high side AC line?

The high side (high pressure components) of the AC system includes the AC Compressor, AC Condenser and the AC Receiver Dryer. The High Side AC hose carries the highly pressurized liquid refrigerant on the discharge side of the compressor to the expansion valve, which is the entry point of the low-pressure side.

Nemecia Mauleon


What if my AC pressure is too high?

When the pressure of the AC system is too high this might indicate a leakage or diminishing amount of refrigerant, both of which require immediate attention. If the AC temperatures are abnormally warm, this could indicate an issue with the compressor that might need repair or replacement.

Becky Glavchev


Do you fill AC on the high or low side?

The LOW side fitting is usually located on the suction hose or line that goes from the accumulator to the compressor. The HIGH side fitting is located on the line that goes from the compressor to the condenser.

Xuehong Popke


What does it mean when the low side is high and the high side is low?

Lower Low Side and Higher High Side Pressures
This condition usually means there is a restriction in the system or the TXV/Orifice Tube is blocked or closed. With a drop, there may be a restriction at the TXV or Orifice Tube.

Suimei Kagan


What happens when you add too much refrigerant?

The main danger with too much refrigerant inside an air conditioner is that it can damage to the compressor. The excess refrigerant will collect inside the compressor and lead to subcooling, temperatures below normal. The extra refrigerant can also flood the compressor and damage its mechanical components.

Serguei Arevalillo


What happens if you add too much Freon?

The extra refrigerant puts more wear on the compressor, and this extra work can cause it to overheat which kicks it off. Also, the extra pressure from the Freon can cause the compressor to start pooling oil inside of it. This will completely burn out the compressor and cause it to need to be replaced.

Rhut Bokenkamp


What happens if I overfill my Freon?

Too much refrigerant can damage your A/C
The potential for the greatest amount of damage, though, is to the compressor. Overcharging the unit can cause permanent failure of the compressor, which is the pump for the refrigerant. Replacing the compressor can actually cost more than replacing the entire outdoor unit.

Terrance Zamzau


What happens when a capillary tube system is overcharged?

If a cap tube system is overcharged, it will back up the excess liquid into the condenser, causing high head pressures. The pressure difference between the low and high sides of the system will now increase, increasing the refrigerant flow rate to the evaporator and overfeeding the evaporator, causing low superheats.

Hafeez Epsom


Why is my AC blowing hot air after recharge?

Leaking Coolant
The chemical Freon or simply you can call it coolant is the reason why the AC cools hot air quickly. The chemical can run out if there is any leakage in the AC. Thus, AC would not work, as there is no Freon in the system.

Rosanne Roy


What would be the symptoms of too much superheat?

Symptoms of this overcharged system include: High discharge temperature. High condenser subcooling. High condensing pressures.

Erotida Gomez De Segura


Can overcharging AC damage compressor?

Not only is overcharging your system potentially dangerous, an overcharged system will not function properly and can seriously damage your A/C compressor or other component parts. The symptoms of an overcharged A/C system are exactly the same as a system that is undercharged: warm air out of the vents.

Giacomo Kallensee


What should the low side pressure be in a r134a system?

This chart details how ambient temperature correlates with the system refrigerant charge pressure, and how it affects high and low side psi readings.

R134a Pressure Gauge Chart.
Ambient Temperature (°F) Low Side High Side
70° 35-40 psi 140-165 psi
65° 25-35 psi 135-155 psi

Marvin Basauri


What should the high and low side pressures be for 410a?

Manifold sets should be at 750 psi (high side) and 200 psi (low side), with a 500-psi low-side retard. Use hoses with a 750-psi service pressure rating. Leak detectors should be of the HFC type. R-410A is compatible with POE oils.

Atou Libera


What should the high side pressure be on auto AC?

The low-side should be near 30 PSI at 90 degrees Fahrenheit or less. Pressure that is too much lower or higher shows there is a problem. On a properly working system, high-side pressure will be about twice the ambient temperature, plus 50 PSI.

Hisashi Torres


Is r134a a high pressure refrigerant?

R134a is used as a refrigerant for medium sized or large heat pump systems. As compared to refrigerants R407c and R410a its efficiency is much higher. However, as compared to refrigerant NH3 its efficiency is lower. The pressure in R134 is fairly low.

Armelina Woernhoer


How do I know if my AC pressure switch is bad?

The most common symptom of a bad AC pressure switch is most likely that you will notice that the AC compressor is cutting on and off rapidly when you are idling your car. These switches between on and off can be noticeable on the engine's rpm, and you may see or feel fluctuations from it.

Setou Langfeld


What is AC pressure?

Your air conditioning system holds a very high pressure between your AC compressor and condenser up expansion valve, and a relatively low pressure after the expansion valve and evaporator and back to the inlet of the compressor. The warmer it is outside, the higher the pressure will be.