Air Conditioner Repair & Troubleshooting You Can Do Before You Call For Service

Al’s Plumbing, Heating and Air Conditioning provides HVAC system Maintenance, Repair and Replacement services.  We repair all brands of HVAC Systems (including American Standard and Trane)**.  We sell and install new Air Conditioners, Heat Pumps and Furnaces from American Standard, ** Ameristar and Coleman.

** Did you know American Standard and Trane are owed by the same company?

American Standard and Trane are major brands of HVAC Systems. They are both owned by the same company (Ingersoll Rand) who makes products under both the Trane and American Standard brand names.  The only difference is paint color and and name sticker.

american standard central air conditioner unit  trane central air conditioner unit

Air Conditioner Repair: 20 Troubleshoot Items You Can Check Before Calling For Service.

It’s not uncommon for your Air Conditioning unit to be working fine one moment, then begin working poorly or quit.  Before you call for service, you can check these items that often don’t require an HVAC Technician to correct.

A/C WON’T RUN: Thermostat Not Working.  Are The Batteries Dead?

If the thermostat’s display is no longer showing numbers, the batteries must be replaced in order for the cooling and heating to work

A/C WON’T RUN: Thermostat Not Working.  Has It Been Set To “Heat” or “Off”?

heat pump thermostat display for auxiliary and emergency heat

It’s possible someone may have turned the HVAC System off because they were too cold.  In spring and fall, the system may have been set to heat, and not reset.

FURNACE BLOWER WON’T RUN: Is the Furnace Shut-Off Switch turned Off

All furnaces have a Shut-Off Switch.  If that switch is off, neither the air conditioner or furnace will operate.   On a GAS furnace the switch looks like a light switch as is typically attached to the furnace (though may be on a nearby wall).  Be sure it’s turned on.  On an ELECTRIC furnace, the shut off will likely look like a circuit-breaker, or a box on the wall with an on / off handle.  It is not unheard of that you might bump this switch while changing a filter, or a child may have turned it off to see what would happen.

gas furnace shut off switch

Gas Furnace Shut Off Switch

CIRCUIT BREAKER HAS TRIPPED.  Turn Breaker to Off, then back On.

photo of interior of a circuit breaker box

Circuit Breakers stand guard in the event there is something wrong occurring with the electrical system in your home.  If a breaker trips, it’s an indication that too much electricity was passing through the circuit.  The tripped breaker protects your homes’ wiring and nearly eliminates the risk of fire due to an overloaded circuit.

NOTE:  When a breaker trips, some will move all the way to the right, but others will move only a little.  Trip all A/C & Furnace breakers to off and then back on.

Keep in mind that a breaker trips because there is a problem.  If the problem was a one-time thing, the breaker will be fine after it’s reset. If it trips again there is something wrong with the air conditioning unit or furnace, or the breaker itself.  Call your HVAC Technician to diagnose and repair the problem. *

Common Causes For An Air Conditioner Tripping The Breaker:

  • Dirty air filter
  • Dirty outside unit
  • Compressor has trouble starting (outside unit)
  • Motor has shorted (fan motor in outside unit)
  • Compressor is grounded (outside unit)

A “grounded compressor” means an electrical component inside the compressor has broken and electrical wiring touched the side of the compressor.

This causes a short, igniting the oil inside the compressor and resulting in a burnout. The circuit breaker trips due to the sudden current surge.  If you reset the breaker, it will trip immediately.

If a grounded compressor is the problem, the compressor must be replaced:

  • If the unit is out of warranty, it’s less expensive to replace the entire outside a/c unit.
  • Replacement compressors must be ordered, they are not a stocked replacement item by HVAC repair companies (because the compressor used is different depending on brand and model).

What You Can Do Before Calling For Service:

  • If your air conditioner tripped a breaker, with no history of that, check the filter before resetting the breaker.  If the filter is clogged, replace it and reset the breaker.  If the breaker does not trip again, it was the filter.
  • The same thing can occur because the outside unit is in dire need of cleaning.  Rinse the coils with a garden hose and reset the breaker.  If it doesn’t trip again, you found and corrected the problem.

very dirty and clogged a/c condenser coil

If the filter and outside unit are clean, call and HVAC Technician to diagnose and repair the problem.



If the furnace blower is running, it’s likely the system is frozen or the filter is clogged.

home central a/c evaporator coil iced up

Door Panel Was Removed To Show Inside The Furnace Where (Frozen) Cooling-Coil Is Located

The Cooling-Coil (inside the furnace and can’t be seen) can freeze up.  There are typically 3 reasons why a freeze-up occurs:

  • The Furnace Air-Filter is clogged.  Check it and replace it if it looks dirty.

dirty and clean furnace air filter very dirty and buckled furnace air filter

  • Too many air-supply vents are closed.  If more that 1/4 of of your vents are closed, you are reducing the air-flow through the entire HVAC system.  The system is designed to move air from all vents.  If too many vents are closed, it cannot move enough air.

Open enough vents so that no more than 1/4 are closed.

air supply ceiling vent

Ceiling Air-Supply Vent

  • The outside unit is low on refrigerant.  Call an HVAC Tech to determine if refrigerant is leaking, fix the leak and recharge the unit.

THE AIR COMING FROM VENTS IS NOT COOL:  Is the outside unit running?

If your outside air conditioner unit is running, your system is likely low on refrigerant.  The lower the refrigerant level, the less cool the air coming from the vents will be. Call an HVAC Technician to check for leaks and recharge your A/C.

If the outside unit is not running, there are a couple things you can check before calling for service.  As mentioned earlier, check the circuit breakers for both the furnace and the A/C.  Trip each one to off, then back to on to ensure they are on.  Many breakers move only slightly when they trip, so they can be off and not look like it.

Note:  Tripping the breakers like this won’t harm your A/C because it’s not running.  If you happen to do this while it’s running, the A/C will shut itself down for a couple minutes, then restart.  It does this to protect itself.

Check The Thermostat to ensure it’s set to “Cool” and the fan is set to “Auto”.  It’s quite possible the furnace’s fan is blowing (because it’s set to “On” instead of “Auto”) and the outside a/c unit is not running (because thermostat is set to “Off” or “Heat” — or set to a temperature warmer than the indoor temperature.

Check the thermostat to ensure the temperature is lower than the indoor-temperature.  Also check that the fan is set to “Auto” versus “On”. 

Air Conditioner Unit Is Running Constantly, but the house is too warm. 

This is likely a problem with the A/C, but it could mean you need more Attic Insulation.  You can increase the benefit of the insulation by also adding a Radiant-Heat Barrier.

These are the most likely reasons it cools all the time, but gets behind:

  • Air filter is so dirty it’s reducing air-flow
  • Indoor Cooling-Coil is so dirty it’s reducing air flow (that coil was show, all covered with white ice, in a earlier photo)
  • Outside Unit needs cleaned
  • Outside Unit is low on refrigerant
  • A/C is too small for the home.  The contractor you bought it from likely did a Cooling Load-Calculation based on the size of your home.  If the A/C Unit is correctly sized, adding insulation and heat-barrier might solve the problem, plus reduce cooling bills.

blown in insulation

Blown-In Fiberglass Insulation

foil radiant heat barrier being installed in an attic

A Foil Radiant-Heat Barrier being installed

Foil radiant heat barrier performance photo

A Foil Radiant-Heat Barrier Keeps Attic Cooler

  • Attic Ductwork Is Leaking Cooled Air.  An HVAC Technician can check this.  They will determine how much air is going into the system (though the return-air ducts) and how much air is coming out (through the supply-air ducts).

gaps in ductwork

Leaking Air Duct

Over the years, your ductwork will likely need to be resealed.  The older the house is, the more likely the ductwork is leaking. The amount of heat in your attic can cause ductwork-sealing products to fail (especially if duct-tape was used).  It’s also possible the ductwork was never sealed to begin with.

The U.S. Department Of Energy (DOE) states that 30-40% of the cooled and heated air is lost due to leaks in the ductwork.  If this is the case with your home, you can lower cooling and heating bills by 1/3 or more by having your ductwork inspected and resealed.  Once the resealing is completed, the Test is repeated to ensure the ductwork is now tight.

Ductwork blockages — especially if flexible ductwork was used.

hanger compressing ductwork  poorly installed flexible ductwork Improper installation results in crushed or blocked flexible ductwork.

There are many things you can do to help keep your home cooler in summer and warmer in winter.

Check out the Posts in our Blog:

Did you know a dirty air filter can increase your air conditioning costs by up to 15%?  A dirty or blocked filter reduces air-flow throughout the entire HVAC system.  This causes your central air conditioner to run longer and harder — wasting electricity, reducing your comfort, and shortening the life of the Air Conditioner Unit.

AL’S TIP: Check or change your furnace air filter once each month.  If it looks dirty, it is, and it’s time to replace it.

dirty and clean furnace air filter

Al’s provides Full-Service HVAC System Maintenance, Repair and Replacement Services on all brands of Air Conditioners, Furnaces and Heat Pumps (including Trane and American Standard).  We perform every service needed to keep your heating and air conditioning system running at its best.

We sell and install American Standard, Coleman and Ameristar — Air Conditioner unit, Furnace and Heat Pump.

Our HVAC Technicians are NATE (North American Technician Excellence) Certified.  They are trained and experienced in providing maintenance and repair of your HVAC System + Installation of new HVAC systems.

Al’s offers Full-Service plumbing.  This includes; clogged toilet repair, water heater repair, water heater replacement for both tankless and tank water heaters, sewer line replacement (under slab or in lawn), trenchless sewer line replacement (in lawn only), slab leak repair, burst pipe repair, repiping, leak detection, water filtration system installation and sales, gas line repair, and gas line installation.

Contact Al’s today to discuss any problem you have with your Plumbing or HVAC System.  We offer appointments at your convenience & are also your Emergency Plumber resource, with 24/7 Emergency Service.  All our Plumbers are licensed and experienced in diagnosing and repairing your residential plumbing.

We Service And Repair All Brands

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Call Al's For A/C Repair

If you need fast, professional a/c repair in the Dallas metro area, give us a call at 972-225-5257 or contact us online.
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