9 Common PTAC Unit Problems & DIY Fixes


Having issues with your PTAC unit? Here are some common problems and their respective solutions. Mind you, some of these problems can be fixed by the owner of the unit, but not all of them. For some, I advise seeking professional assistance. With that out of the way, let’s see what we’re dealing with:

1. Water Leakage Inside the Apartment

PTAC units are typically installed in an apartment’s living room, where there is less ventilation than the outdoors. Thus, moisture builds up inside the PTAC itself if it is not properly maintained (i.e. actuation of the unit by the tenant after heating/cooling season). Moisture accumulates inside the PTAC unit when the unit is not run for long periods of time, and this can cause water to build up inside.

The water can cause problems such as mold on the PTAC unit itself, rot in the walls if it leaks through to them, and even damage to other objects in a home.

Solution: By using a dehumidifier during the winter cooling season, moisture build-up is prevented from occurring. Moisture buildup can be monitored by checking the drain pan for water build-up. If it is full, then drainage holes should be made larger so that the amount of condensation and buildup will decrease.

Condensation and buildup can also be eliminated by properly maintaining a PTAC unit and having it serviced annually to ensure proper function.

2. Humming or Crackling Noise

While this problem does not necessarily cause problems for the PTAC unit, it is annoying to hear in your home. The humming or crackling noise that is heard when the fan in the PTAC runs can be caused by many different factors. The source of the noise will play a major role in determining the best solution for the problem.

The noise can be caused by a losing blade in the PTAC unit. This problem is often easy to spot because there will be a loud noise from within the unit itself when it’s turned on, and there will also be a visible gap between the two fans inside of the unit. However, the noise can also be caused by a faulty or broken mounting bracket attached to the ceiling or wall that supports the unit itself.

Solution: If the noise is being caused by a loose blade, you can buy a new one and replace it without requiring much effort. If, however, the noise is resulting from a faulty or broken mounting bracket, the problem will be a little more difficult to fix.

The good thing is that it’s not usually so expensive, and it only requires professional assistance to solve this problem. This can usually often be fixed by having another PTAC installed in place of the current one.

3. A.C. not blowing hot/cold air

Another common problem is the A.C. unit not turning on. The most likely cause for this in many units is a clogged air filter. When it does not turn on, unplugging and then plugging back in the PTAC often fixes the problem by releasing an internal switch that was stuck when debris blocked it.

Other common problems include clogged grills and filters in front of PTAC units due to pet hair or other debris being blown into them from air trying to move through into the room. There may also be a problem with the thermostat.

Solution: Debris can be cleaned out of grills, filters, PTAC units themselves, etc., to ensure the proper functioning of the unit. Vacuuming these filters can make a great difference in air quality, and it is advised to vacuum the filter once a month.

In case of thermostat issues, having someone check or change out the thermostat into one that is properly sized for the room space will often fix problems with the heating or cooling not working properly. A service call is also helpful if there are any other problems that are not simple fixes.

4. Temperature Mismatch

If the room is not getting the desired temperature, look for common problems with thermostats. The heat or air conditioning may be stuck on if the thermostat has been frozen over by ice. It can also appear that there are no controls for heating or cooling when it actually has one of two different settings: “on” and “fan-only”.

Solution: In order to prevent ice from forming on a thermostat, keep it in a reasonably warmer room. If the problem persists, use a hairdryer or heat gun to melt away any remaining ice.

In addition, make sure that the heating and cooling feature is actually turned on. The “on” setting allows for heating or cooling when the fan is also turned on. If this is not the problem, then it may be time to call a professional and schedule a service visit.

5. Push buttons Not Working Properly

If the push buttons are not working properly, there is likely an issue with the button panel itself or one of its components. The source of the problem can often be determined by which button is malfunctioning.

If it’s the unit’s on/off switch, this would be a good indicator of faulty wiring or a loose connection for that particular component. If the buttons for the directional settings are not working properly, there may be an issue with the controller itself.

Solution: The best way to fix these problems is probably by replacing the panel altogether. However, if only one or two of the buttons are malfunctioning, it might just be something as simple as using a can of compressed air

It can be difficult to get inside of the unit in order to attempt do-it-yourself work on a motherboard or any other part that requires replacing. Instead, it’s recommended that you look for a service center to handle this sort of problem.

If it’s not the on/off switch, the most common cause is debris collecting behind or inside of buttons. A quick clean can be all that it takes. If not, there may be additional problems with the button panel itself and professional attention will likely be needed for repairs.

6. Ice Forming on the PTAC

This is a common problem with some types of heating and cooling units. If ice is forming on the PTAC, it can be a result of either a thermostat problem or a faulty fan. The thermostat will not allow the temperature in the room to rise until it’s been fixed. That being said, when ice forms on the PTAC itself, it’s likely that there is an issue with its internal fan.

When ice forms on the PTAC, you might experience various risks or challenges that can eventually lead to damage due to the unit either no longer working at all or repeatedly turning on and off. The ice buildup can also cause it to short out, in some cases.

Solution: There are many solutions that one could try before considering a replacement of PTAC units themselves. If you think that your thermostat is malfunctioning, a simple service visit might be the solution. If it’s the fan that has been damaged by ice, getting someone to come out and either clean off the PTAC will likely fix the problem.

If a thermostat issue is preventing the PTAC from heating or cooling a room, it’s best to turn it off at the breaker and wait for repairs. Otherwise, you may risk further damage to the unit or an electrical fire hazard due to overheating.

In case the fan is not operating properly, this will likely cause the PTAC to overheat. You can take steps to try and fix this problem by cleaning off the unit. It may need professional attention, however. The freezing problem can usually be prevented by keeping a thermostat in a reasonably warmer room, but if it still persists you may need to schedule professional assistance from an HVAC specialist.

If you have tried all of these fixes, then you may need to consider freeing up some space in your budget for a replacement unit.

7. Tripping of the Circuit Breaker/Fuse

This is one of the most common problems that are associated with the PTAC. As you might imagine, protecting circuits against overloads or short circuits can be a safety measure, but there are also circumstances in which it’s used as a type of protection feature to prevent fires. If the circuit breaker is tripped for no clear reason, this would typically be an indicator that the problem stems from the unit itself.

If this happens when there is not much in use or when it’s something that has not been turned on, then you can assume that there are issues with the wiring within the unit. The wiring may have become damaged due to wear and tear or severe mishandling prior to installation.

If it’s tripping when there is an abundance of electronics in use, this would be an indicator that the unit may need to be checked out for other issues. One common problem that can lead to consistent circuit breaker tripping is poor airflow through the venting system. If this has become clogged or obstructed in some way, this will prevent proper heat distribution and can cause the circuit breaker to trip.

In either case, if you need assistance with wiring or unit repairs, it’s highly recommended that you get in touch with a service center like WeatherMakersNYC for professional assistance.

Solution: If the tripping is an isolated incident and not a general problem, you should be able to remedy the situation by getting the unit inspected. In some cases, a simple cleaning or maintenance might do wonders in preventing further circuit trips. If it is a wiring issue, then you’ll likely need to have an electrician fix it.

If you’re having problems with airflow in your system and it’s causing the tripping feature, your best bet is to schedule a repair with a service center like WeatherMakersNYC. The experts will be able to check out the system and give you an estimate of what might need to be done.

Although very rare, it’s also possible that it’ll require additional parts or accessories that aren’t included in the initial PTAC unit purchase.

8. Cold draft coming from the sides of the unit

A cold draft coming from the sides of the unit is a common problem that can be caused by a number of different issues. A cold draft is, in a majority of cases, an indication that there is a problem with the blower of your unit. It may be time for new ducts and vents, and it may even be worth having the entire system inspected.

In some cases, it could be due to a lack of insulation in the wall cavity where the PTAC is installed. If there is air infiltration coming through the seams or gaps in the unit itself, this will also cause a draft. There are also some cases whereby the cold draft is caused by air from outside entering the venting system. If this is the case, you’ll need to have an expert inspect your unit and make sure that it’s sealed properly from the exterior.

One crucial thing to keep in mind about cold drafts is that they commonly cause the burst of hot water coils in PTAC units. That’s one of the reasons why you should schedule regular maintenance with a service technician to help prevent this from happening.

Solution: If the cold draft is coming from the sides of the unit, it’s most likely an indication that there is something wrong with the blower. You’ll need to have it inspected and, if necessary, replaced.

If the draft is being caused by a lack of insulation in the cavity, you should be able to remedy it yourself with a DIY project. In some cases, installing weather stripping around the unit and adding additional insulation might do the trick.

In most cases, however, it is definitely worth having the unit checked out by a professional. Cold draft coming from the sides of your PTAC may also indicate a more serious issue with the sealing of your unit or even issues with the insulation, which can present a number of different problems for you.

In any case, if you notice a cold draft coming from your unit it’s best to get in touch with an expert as soon as possible.

9. Black mold coming from air vents

Mold is never a good sign, and black mold is even worse. This particular type of mold can cause a number of problems for your health, so it’s crucial to take care of it as soon as possible.

One of the most common causes of mold in PTAC units is condensation. When the unit is cooling down, moisture often builds up on the exterior of the unit. If this moisture isn’t allowed to dry properly, it can create an environment in which black mold can thrive.

In addition to condensation, there are a number of other causes of mold growth in PTAC units. These include inadequate ventilation, high humidity levels, and dirty air filters.

Solution: The first step in taking care of mold is to identify and fix the cause. If the problem is due to condensation, you can help mitigate the issue by using a dehumidifier in the room where the unit is installed. You should also make sure that the unit has proper ventilation and that the air filters are clean and in good condition.

If the mold is being caused by another issue, such as humidity or dirty air filters, you’ll need to take care of those problems in order to get rid of the mold. High humidity can be controlled with a dehumidifier, and clean air filters will help keep the unit running more efficiently.

Mold can be very hazardous to your health, so it’s important to get rid of it as soon as possible. If you need help or advice with PTAC unit mold removal or any other aspect of HVAC maintenance contact professionals to eliminate the mold and get your unit back on track.

Peter Baron

I learned how to fix many appliances while working part-time in a repair shop. Appliance Solver is the result of this experience, coupled with my interest in writing helpful content online. When I'm not fixing stuff, I'm usually either playing with my kids or on a walk with my golden retriever. Doesn't get much better than that.

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