Question about Intertherm P3RA-048K Air Conditioner

1 Answer

M#13qc-042k system will not go into defrost i replaced defrost board & sensor still no defrost

Posted by on

  • Danny Clark
    Danny Clark May 11, 2010

    What is it set on?

    how are you trying to get it into defrost mode?

    Are you forcing it to frost up so the sensor senses frost before attempting a forced defrost cycle?


1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 19 Answers

There is typically a set of jumper pins on the defrost control board that allow the system to go into defrost after 30, 60, or 90 minutes of run time. There are also two bare pins that say "test" on them. While unit is running, approx 15 min or so in heat mode, short those two pins together for about 5 seconds, this will force the unit into defrost mode. If it still does not work, you might still have a defective board. Depending on the humidity in your area, that is how you determine the defrost interval.

Posted on May 18, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

While in heat mode the condenser freezes up.1200 model

This is how air conditioners work.

They transfer heat from (usually) hot places to cooler places.

When working in the opposite direction, the machine is attempting to pump heat from the cool place (making it colder) to the warm place (making it warmer).

Flushing the frozen condenser with cold water adds more heat to defrost the condenser, but it will refreeze when you try extracting more heat from the cold place.

Dec 10, 2013 | LG LS-K1830CL Cool Mini Split Air...

1 Answer

I have noticed my heat pump is freezing up on the outside unit, we have had freezing rain and snow the last 2 days but I have never noticed ice accumulation on the outside of the unit, it also seems like...

In freezing weather the heat pump efficiency drops. The freezing is normal. The equipment has a board and sensor to defrost your heat pump. Now this system can fail but freezing rain and snow get pulled into the unit get pulled into the unit coil and freeze blocking airflow. You can defrost the unit by turning it to cooling. This is what the defrost board does automatically.

Dec 27, 2012 | Goodman Air Conditioners

1 Answer

LED on defrost control board is blinking 3 times on American Standard 2A6H1030A1000AA. What is this error code?

Does not initiate defrost on ots own. Loose sensor. If sensor is not loose replace defrost board and sensor. Russ

Mar 24, 2010 | Air Conditioners

1 Answer

Defrost cycles needlessly for extended time period

Without knowing what the problem was with the old board, you're not going to be able to figure much out, I don't think.

Did you check that temperature sensor I mentioned? You will have to pull the top off to get access to it. Normally found connected to one of the tubes for the coil, silver in color, with 2 wires connected to it, near the bottom of the base of the unit.

Dec 13, 2009 | Air Conditioners

1 Answer

Fan freezes up with ice in winter

They need air, do not cover it when in use.

If ti cools fine in summer then you just have a defrost problem.

Make sure the outdoor coil is clean.
If the coils are clean, then you have a bad defrost control.

In heat mode the unit should go into a timed or temp controlled defrost. If it is frosting up to the point of stopping the fan, in heat mode only, and otherwise operates properly, then its a bad defrost control.

It is reccomended that the defrost temp sensor be replaced at the same time the defrost control board is replaced. Some temp sensors are part of the board and not a seperate component, but not most.

Aug 19, 2009 | GE Zoneline AZ25E12D3B Air Conditioner

1 Answer

System does not go into defrost

Did you check the solenoid on the reversing valve? Has the compressor ever been replaced?

Most reversing valves are normally in heat pump mode, and when the solenoid is energized, it is in A/C mode (in summer cooling, the valve is energized.). If the solenoid is bad, then the unit can not switch to defrost.
If the compressor has been replaced, there is a chance that the reversing valve might have some trash in it, preventing it from switching over. Lightly tap on the valve when defrost or A/C mode is being asked for.

Jan 22, 2009 | Intertherm P3RA-048K Air Conditioner

1 Answer

Defrost board contacts in relay chater and do not let defrost

is sensor at proper location? try turning sensor ? Ohm sensor as you turn it.

Jan 14, 2009 | Goodman CLQ36AR49 Air Conditioner

1 Answer

Out side unit will not go into defrost cycle

most likely a bad temp sensor on the outdoor coil. you are seeing ice so its cold enough to defrost but the sensor is not seeing ice so it doesn't. usually a generic 3/8 or 1/2 clamp on sensor will fix. you can freeze the sensor with a little r22 and it should close and fall into defrost or jump it and it has to proof closed and the unit should defrost. if you jump it you may have to speed up the board to diagnose. usually jumping test pins together throws it into a 5 sec in 20 seconds out cycle. kind of like turning a 24 hour days into 24 seconds. or to protect the board you can just find the sensor pull it, replace it and watch what happens next cold night. good luck

Nov 10, 2008 | Intertherm P3RA-048K Air Conditioner

Not finding what you are looking for?
Intertherm P3RA-048K Air Conditioner Logo

210 people viewed this question

Ask a Question

Usually answered in minutes!

Top Intertherm Air Conditioners Experts


Level 3 Expert

2963 Answers


Level 3 Expert

347 Answers

Brad Brown

Level 3 Expert

13522 Answers

Are you an Intertherm Air Conditioner Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides