John Moore Services
Rated: 4.8 / 5 based on 2719 reviews

Air Conditioning Repair

AC Repair Services for the Greater Houston Metropolitan Area


Air Conditioning Repair by Houston’s Best and Most Recognized HVAC Service Provider Since 1994

John Moore air conditioning specialists are highly trained to repair virtually any make and model of air conditioning system. What’s more, we offer in-house financing with approved credit and offer the John Moore 10-year Parts & Labor Warranty to protect your investment.


Call 877-730-2525 and schedule a A/C Repair Specialist.



Condenser HVAC unit

Refrigerant Leak

Refrigerant leaks are among the most common problem

Drain Line Leak

R-22 being phased out by the year 2020

Condenser Repairs

What’s a Condenser?

Chances are you’ve noticed one or two large, metal boxes outside of your home. Those are your AC system’s condensers. Inside of the condenser is your refrigerant, a compressor, a condenser coil, a capacitor, an electromagnet, a fan, some relay switches, and other electronic and mechanical components that vary from system to system. As we discussed in the Basic Operations section, your condenser is where a lot of the magic happens; it’s where the refrigerant is compressed and pumped to the evaporator coil, and where the refrigerant returns to release heat.

What to Look For

If you notice that your home isn’t cooling or is taking a long time to cool, it could be a condenser issue. If you go outside and notice any leaks around your condenser or strange noises when the fan turns on, you should call an AC technician immediately.

What Causes Condensers to Malfunction or Fail?

One of the primary suspects is electricity, or lack thereof. The first thing we do before we even open up the condenser is make sure it’s getting electricity. If we check the breaker box and notice a problem, we will have to refer an electrician to solve that issue first.

The majority of issues we find in condensers are refrigerant leaks, broken capacitors, broken belts, faulty relay switches, motor failure, or a faulty or broken condenser coil. There are a number of other issues, but these are the most common ones.

How We Fix It.

After ensuring your condenser is being supplied with electricity, we take into account any signs you may have noticed. Because refrigerant goes between a gas and a liquid state, refrigerant leaks aren’t always noticeable. So the next thing we do is use an electronic leak detector to find out if your refrigerant is leaking and locate the leak. If we do find a leak, we can replace the pipe or coil that’s leaking and recharge your system.


If your system uses R-22 refrigerant, keep in mind that R-22 is being phased out by 2020. That means if your refrigerant leaks after the year 2020, you will have to replace your entire system. If we are inspecting a system that uses R-22 refrigerant, we will give you options to replace your AC system with a new one that uses R-410a. We strongly recommend upgrading your system before the 2020 phase out so you can budget, plan ahead, and not be surprised with a large expenditure in the near future.

After we determine whether or not a refrigerant leak is causing your condenser to malfunction, we will run some other diagnostics to test the capacitor, belts, relay switches, condenser coil, and fan motor. We will then provide options for any parts that need to be replaced in your condenser.

Drain Line

Condensate drain pain and drain line

Drain Line Leak

Water stains on ceiling could be a pipe or drain line

Drain Line Leak

Rodent damage to drain line

Condensate Drain Line Repair

What’s a Condensate Drain Line?

As we mentioned in the Basic Operation section, your AC system has an evaporator coil in your attic that get’s really cold, usually as low as 40 degrees fahrenheit. As this coil cools the warm air moving past it, it produces condensation. Underneath the evaporator coil is a drain pan that catches condensation as it falls. The condensation is then directed through an insulated ¾ inch PVC pipe that ties into a drain line underneath a sink in your home. This ¾ inch PVC drain is your condensate drain line.

What to Look For

If you notice water marks on your ceiling, it could mean one of two things:

  1. You have horizontal pipes that are leaking or,
  2. Your condensate drain line is backed up or sweating.

We won’t know what’s causing the water to drip to your ceiling until we go to your home. If it’s a leaking pipe, then we would refer a plumber to do a horizontal or whole-home repipe. But if it’s a sweating or backed up condensate drain line, a John Moore AC technician can solve the problem with a condensate drain line repair.

As time passes, algae can start growing or rust from the evaporator coil can find its way inside of your condensate drain line. Rust, algae, or a combination of both get stuck at the connection point underneath your sink, and water begins to back up, causing your drain pan to overflow. Luckily, there’s a secondary, emergency condensate drain line that can prevent your drain pan from overflowing for some time. The draining point of your emergency condensate drain line can be found somewhere underneath your roof soffits, usually above a window. If you see this pipe leaking water, you should call an AC technician to unclog your condensate drain line and empty your drain pan.

What Causes Condensate Drain Line Leaks?

So what causes the water marks on your ceiling? It could be two things:

  1. Your drain pan could be overflowing with water or,
  2. The insulation around your condensate drain line has deteriorated or been chewed through by rodents in your attic, causing the drain line itself to sweat.

To identify the specific cause, a John Moore technician will inspect all the components of your AC system including the evaporator coil, drain pan, and drain lines.

How We Fix It.

If your condensate drain line is backed up, we clear the line from the connection point under your sink and inspect the water to determine whether the culprit is algae, rust, or both. If it’s rust, we will recommend replacing the evaporator coil so the same blockage doesn’t happen again anytime soon. If we find algae, we will recommend using Plumbers’ Formula 6, a special plumbers formula you can put into the condensate drain line service port every month or so to prevent algae build-up. From there, we empty and clean the drain pan, run clean water through the condensate drain line to clean it out, and clear out the emergency condensate drain line with a wet vac.

If we inspect your condensate drain line and find that a lack of insulation is causing it to sweat water, we will look for signs of rodent bites and deterioration to determine the cause. More than likely, the insulation has deteriorated over time, but it’s also not uncommon for rodents to live in attics and chew on the insulation around the pipe. In either case, John Moore AC technicians can replace this insulation. But if we do determine that rodents chewed through the insulation, we will recommend and refer pest control to inspect your attic, rid it of all rodents, and take measures to prevent the problem from happening again.

If your ceiling or sheetrock incurred damage from a condensate drain line issue, our Renovation and Remodeling team can provide expert ceiling / drywall repair and painting services to make it look like the damage never happened.


Resizing and replacing air ducts


Damaged air duct connection


Dampers used to regulate air flow

Air Duct Design and Air Balancing

What is Air Duct Design and Air Balancing?

Air Duct Design is the process of resizing and replacing air ducts in your home. Air Balancing is when we make sure a given air register or all air registers in your home are releasing the correct amount of air at the right temperature.

What to Look For

If you feel like the temperature and comfort level of the air in your home is inconsistent from room to room, then your air ducts may need to be resized or balanced.

What Causes Unbalanced Air Distribution?

Several things can cause inefficient ductwork or unbalanced air distribution:

  1. Your Air Duct has been pierced or crushed. It’s not uncommon for homeowners to accidently crush an air duct with a storage box or for another service person, like a cable guy, to accidentally lay on the duct work.
  2. Your air ducts were built too small to begin with.
  3. The tonnage of your HVAC system is too small or
  4. There is extra heat that was unaccounted for in the initial sizing of your equipment. Say, for instance, you add a flat screen TV, a computer, and game consoles into a room of your home. All of these devices will create extra heat in your room that wasn’t accounted for when the branch of ductwork leading to that room was sized.

How We Fix It.

To fix uneven air distribution in your home, the first thing we do is conduct a heat load calculation. Based on factors like the size of your home, air leaks, heat producing electronics, and plants, we determine the ideal tonnage of your system. We then check the tonnage of your AC system, and if it’s too small, we will recommend a replacement of your entire AC system.

After we check the tonnage of your system, we will make sure your air ducts are intact. If we find any pierced, crushed, or undersized air ducts, we will determine what the cause was. If we determine rodents chewed through your duct work, we will patch up the holes and refer pest control to rid your home of rodents so it doesn’t happen again. If we determine your ductwork is undersized, we will recommend resizing them.

We will also go from air register to air register to measure the temperature of the air coming out versus the temperature your thermostat is set to. Generally, the air coming out of each register should be 20 degrees below the temperature your thermostat is set to. If the air coming out of a register is not 20 degrees below your thermostat’s setting, we will recommend an air balance. To balance the air in your home, we install various dampers to collars where your air ducts attach to the air plenum. We will then adjust each damper until the temperature of the room in question is what it should be.

If you live in a large, two-story home, we can also install a zone system with electronic dampers that can balance the air room by room or story by story.

As you can tell from the basic description of how an AC system works, there are a lot of components that affect one another.

If something happens to one part of your AC system, it might not shut down immediately, but it will begin to affect other areas. For instance, if your refrigerant starts leaking, the indoor evaporator coil will get too cold and freeze up, which could permanently damage it. Just like with a car, as soon as you notice something isn’t right, you should call an AC technician before the problem gets worse.

It’s not uncommon for homeowners to wait until there are obvious signs before calling. The majority of AC related calls we get from homeowners are when their home can no longer reach a comfortable temperature or their system completely stops working. Unfortunately, waiting could mean more problems, more repairs, and more money spent down the road. In order to know what to look for before it’s too late, here are common repairs John Moore makes, what causes the issue for the repair, and what to look for.


Other AC Services

HVAC Replacement and Maintenance Services

HVAC Replace

Air Conditioning Replacement

Is your AC system more than 10 years old? Are you constantly calling for repairs? Does your condenser still use R-22 refrigerant?

If so, you may want to consider replacing your entire AC system. After your AC system reaches a certain age, it makes more sense to invest in a new AC system altogether rather than repairing it one piece at a time. To learn more about John Moore’s AC replacement program, our warranty, and the cost-advantages of replacing your AC system, visit our AC Replacement page.

HVAC Maintenance

Air Conditioning Maintenance

Do you want to prolong the lifetime of your AC system? When was the last time you cleaned your condensate drain line? Have you changed your air filter recently?

Learn how you can keep your AC system in optimal running condition and how John Moore can help extend the life of your AC system on our AC Maintenance page.


Meet Your HVAC Technician

What Our Customers Are Saying

  • John Moore Service Technician Kiel M.Great Service. Very polite and knowledgeable. Kiel explained everything and fixed the problem with my downstairs AC. He also determined that the issue with the upstairs AC was due to a problem in the main breaker. He setup an appointment for an electrician to come in.

    - Air Conditioning
    Houston, TX - 09/06/17
  • John Moore Service Technician Kiel M.Great Service. Very polite and knowledgeable. He was able to quickly resolve the problem with my downstairs AC and had it up and running within 45 mins. He also determined the issue with the upstairs AC and scheduled an appointment with an electrician to followup.

    - Air Conditioning
    Houston, TX - 09/06/17
  • John Moore Service Technician Chris E.Chris did an excellent and through job on checking our home's ac unit. He even gave me some quick tips to help maintain the unit. He was friendly and very informative. He gave me some recommendations to help improve the units service.

    - Air Conditioning
    Houston, TX - 09/05/17
  • John Moore Service Technician German (Alex) P.Pleased with service and with the technician German P who came out to repair my a/c. He took care of my problem in a timely manner and explained everything to me. Thank you German P for being available and coming out on Labor Day.

    - Air Conditioning
    Houston, TX - 09/07/17
  • John Moore Service Technician German (Alex) P.pleased with service and with the technician German P who came out to repair my a/c. He took care of my problem in a timely manner and explained everything to me. Thank you German P for being available and coming out on Labor Day.

    - Air Conditioning
    Houston, TX - 09/07/17
  • John Moore Service Technician Derric B.During August and September, I used John Moore for a new AC system with ductwork and insulation and a new attic ladder, new breaker unit, new wiring, and a new toilet. The Moore people were very nice and professional. JM may not be the cheapest around but they are the best and since my home is over 30 years, I needed to have it all done and done correctly.

    - Air Conditioning
    Houston, TX - 09/20/17
  • John Moore Service Technician Kiel M.Third time using them. They replaced a component that was under warranty with no issues. Kiel Mire has always been very professional and courteous on all occasions. I highly recommend getting services from this exceptional ac professional. We will continue to use john moore for any home repair needs.

    - Air Conditioning
    Houston, TX - 09/11/17
  • John Moore Service Technician Jose P.Excellent customer service, very knowledgeable service technicians. Jose took time to locate our problem and explain what needs to be done to fix it. He was able to come within 3 hours after I reported a problem with my air conditioning. I highly recommend John Moore Services.

    - Air Conditioning
    Houston, TX - 09/23/17
  • John Moore Service Technician Charles J.Charles came out to fix my AC system, he quickly diagnosed the issue, made the repair and even showed me the bad part. Charles was very courteous and explained everything and the pricing. Highly recommend John Moore.

    - Air Conditioning
    Houston, TX - 09/06/17
  • John Moore Service Technician Layth J.Layth did an amazing job... he went above and beyond my expectations... endured horrible traffic to obtain the parts I needed and completed the job as promised... I really appreciate his effort to get our a/c running as soon as possible... I give him 5+ stars

    - Air Conditioning
    Houston, TX - 09/05/17
  • John Moore Service Technician Mauricio G.john moore did a great job with our ac. they clean after they installed our furnace and a/c. I would recommend them to anyone who needs this kind of service

    - Air Conditioning
    Houston, TX - 09/14/17
  • John Moore Service Technician Hamad D.I had a young man named Hamad D. service my AC unit. He took his time explaining every step needed to check for leaks, Defrost the unit as it had frozen in the attic. He explained the cost involved and was very through about checking every little thing.He was a very hard working and polite young man. I would call again and request him if needed in the future.

    - Air Conditioning
    Houston, TX - 09/21/17
  • John Moore Service Technician Charles J.Charles James came out to service my A/C which was not cooling. He arrived on time and quickly determined the problem. He did a system re-boot and everything is working fine.

    - Air Conditioning
    Houston, TX - 09/26/17


(877) 730-2525

Or click below to schedule service online.