Split Ac System Repair

What are your symptoms?

We will assume that before we begin any of the steps below, we have already checked that the air filter is clean, batteries in the thermostat are good and the settings are correct (cool - auto - 75 or low enough to come on).

• Unit does nothing no matter where I set the thermostat.
• Unit comes on (makes noise) but air never comes out of the vents.
• All of a sudden, unit started blowing warm air.
• It seems as if the air just got warmer and warmer.
• There is water dripping or running out over my window or a place it never has before.
• My power bill is too high.
• Unit stopped working I turned it off for an hour, turned it back on and it worked.

Unit does nothing no matter where I set the thermostat

Ok, now we will start by turning the thermostat too cool, auto and 60 * now assuming you have a split system, go outside to the unit. Bring along a 5/16 inch nut driver, 1/4 inch nut driver, voltmeter (I prefer a fieldpiece), take the cover off the unit now before doing anything take notice of the contactor "is it pulled in or not? Is it humming or not? If its pulled in than you'd know 24 volts was coming from the indoor unit, confirming that the transformer and the thermostat were good, [possible problem (bad or no power coming out of disconnect box, blown fuse at disconnect, tripped breaker at either disconnect or breaker panel). If not than you need to check thermostat. If you do not have continuity with your meter between R and Y and it has been, at least 5 minutes (change thermostat). If thermostat is in fact making continuity between Y and R than its doing its job. At that point, you are headed for the attic or garage to check the indoor unit.

                When you get to the indoor unit, the first thing you need to do is remove the cover with holes in it. Once panel is off find, the control circuit board look to see if there are any lights lit up. If you do see a light watch it, count the slow beeps then count the long beeps. Refer to the back of the panel you took off; there is a diagram that tells you what is wrong with the unit. Now if you did not see any lights and you do have 120 volts coming into the circuit board, then you have a bad board. 

Now if when you look at the board you do not see any lights, and then turn around check the power at the plug. You should have 120V at the plug, if you do not. (Possible problem Tripped breaker at main panel). If you do have the 120 volts to board and still have no led lights coming on check to see that 24 volts is coming out of board. check for 24 volts across the C and the R terminals you shold have 24 volts coming out. If you do not then check your transformer. To check the transformer do this: verify that you have 115 volts going into the transformer, if you do then check to see if 24 volts is coming out of transformer. If you do have 24 volts coming out then you have a bad board. If however you do not have 24 volts coming out of transformer then you have a bad transformer.

Once power is established, watch the unit, operate if it still does not work check for flashes on board and refer to diagnosis chart.

Unit comes on (makes noise) but air never comes out of the vents.

 The first thing you need to do is find the air handler or furnace. It is usually located in the garage or in the attic; you might need a 6 ft or an 8 ft ladder if it is in the attic. Once you locate the unit, and remove the panel. Are there any lights on, is the motor hot to the touch, these are both great clues as to what is wrong. Lights- if there is a light on that is your control board and will tell you what is wrong if you reference the blinks to the diagnosis chart on the back of panel. If the motor is hot to the touch before you stick your hands in there, make sure the unit is unplugged.

A hot motor indicates that it needs replaced.

All of a sudden, unit started blowing warm air.

 If the air conditioning system in your home is blowing air at all, then we start outside at the condenser, usually located on the side of house. As we walk towards the unit listen (is it making noise or vibrating), if its noise than we know it has power so we need to know what is making noise, and is the fan spinning.

Yes the fan is spinning. You might have a leak in your refrigerant lines.

 No, fan motor is not spinning. If the unit is not making a loud noise at all check the disconnect, fuses or the breaker in the main panel. If that does not help, then call us now to find your AC doctor.

 It seems as if the air just got warmer and warmer.

 Although many things could cause this, it is usually a sign of a leak. Over time, a leak in the AC refrigerant lines “will slowly leak out refrigerant gradually making the air warmer. Over time, it will completely stop working. Left alone it could cause further damage at worst case, a bad compressor. Other signs of a leak are

• The big refrigerant line is not cold.
• The air blowing out of the air conditioner is not cold.
• Oil anywhere in sight, refrigerant is oil based so anywhere it leaks, will have oil.

If you think, you have a refrigerant leak. You will have to get a trained air conditioning repair technician to do the job for you. As the refrigerant is closely monitored by the EPA.

                      You need an Air Doctor Call (702) 243-4000

There is water dripping or running out over my window or a place it never has before.

This is caused by a clogged primary drain line, you need to find somewhere on your house a small white 3/4 inch pvc pipe sticking out of the wall, usually low on the wall. That is your primary drain line and it is probably clogged.

Tools needed

• Tank of nitrogen
• Regulator
• Hose for regulator
• Rag

Attach regulator to nitrogen and hose to regulator.

Stick other end of hose into drain, wrap rag around PVC and hose, to seal.

Open nitrogen and regulator. This should un-clog most obstructions. If that does not solve your issue then you might need to find the indoor unit, in either the garage or the attic. Coming out of the indoor air handler or furnace, you will see two drainpipes. Now for this next step you will need three more pieces of equipment.

• Right size pvc coupling 1/2 or 3/4 inch usually 3/4
• PVC glue
• PVC cutters

Now cut both of the drain lines in the middle of a straight run, at least 4 inches long.

Now blow through the lines both ways.

Now re-attach both lines using couplings and make sure to use plenty of glue on all four connections.

My power bill is too high.

There are many reasons why an air conditioner might be using too much power.

1- You could have loose or burning electrical connections

2- Could have a bad motor (failing motors are usually hot to the touch).

3- Compressor valves could be bad (Need new compressor).

4- Could have a bad Reversing valve.

5- Low or high refrigerant charge can cause this.

6- Dirty filter or indoor evaporator coil.

7- Dirty condenser coil.

Here is what you could do Go outside to the air conditioner. Unplug it at the disconnect or turn off the breaker, to disconnect power. Now grab your garden hole and spray out the fins of your air conditioner, careful not to bend or damage any of them. It works best if you spray top to bottom.

Next, make sure nothing is obstructing the airflow at least 12" away from all sides of the ac.

Replace the air filters in the house.

If you still have a higher than normal energy bill, you should call a professional.

Unit stopped working, I turned it off for an hour, turned it back on and it worked.

That is a typical sign of a bad motor, usually it is the outside condenser motor, but could be the indoor blower motor. One way to tell for sure if a motor is going bad is to let it run for 5-10 minutes. Turn off power to the air conditioner, then touch the motor careful not to burn yourself, as a failing motor can feel hot to the touch. If it is hot, it has to go.

By Stephen Gamst, Air Doctor Inc.