Rheem AC troubleshooting

Got Rheem air conditioner problems? We’ve got answers. Check out our Rheem AC troubleshooting tips before you call a repairperson.

But if you’re uncomfortable performing any of these fixes, don’t worry! We can connect you with a local HVAC pro who can identify and solve your Rheem air conditioner problems.

Rheem AC is not cooling

Set your thermostat to “cool” and “auto.” Lower the temperature several degrees and see if that makes a difference. Set the thermostat to “heat” and check for warm air coming from the vents. If your system doesn’t start heating, the problem is likely with your thermostat.

Dust inside and around your thermostat to ensure it can accurately read the indoor temperature. If it takes batteries, change them.

Check the air filters in your home and AC. You should change them regularly. If they are very dusty, they can block airflow, causing your HVAC system to malfunction. Change your filters every 60 to 90 days or sooner, if needed. 

Look inside your ductwork for blockages or leaks. You can remove the registers and look inside with a flashlight. Remove any items that have fallen in or debris that’s gathered. Repair leaks with aluminum foil tape or sealant. Consider hiring a duct cleaning service for a full duct checkup.

Check your compressor (large outdoor unit). Turn it off and remove the external cover – you may need to unscrew it with a screwdriver. Now go to the indoor unit to ensure the evaporator coil is free of dirt and debris. The evaporator coil is the part covered in U-shaped metal tubing. You can clean it with evaporator-safe coil cleaner if necessary.

Inside the compressor, see if any components are frozen. This could signify a refrigerant leak or several other serious issues. If you notice anything frozen, call an HVAC tech for help.

If these Rheem AC troubleshooting tips don’t resolve your issue, it’s time to call a professional to look into the cause further.

Rheem AC compressor is not running

Make sure it’s turned on. Check that the switch it’s connected to is also on. Look at your electrical box. If you’ve tripped a breaker, reset it.

Set the thermostat to “cool” and “auto.” Ensure the temperature is set correctly (about 78℉ is ideal in the summer). Clean in and around the thermostat to clear dust away from the sensors. If your thermostat takes batteries, change them.

Turn off the power and open your compressor (large outdoor unit). You may need to unscrew it with a screwdriver. Clean out any debris that’s fallen inside, like sticks or leaves. Note whether components appear frozen.

Try to start the Rheem AC again. If it still doesn’t start, stand by the compressor and listen for noises. If you hear buzzing, the issue may be your start capacitor. If you hear clicking, the problem may be the start relay. Neither of these is a DIY job, but knowing what’s wrong can help your HVAC technician address your Rheem air conditioner problems.

Rheem AC smells bad

Different scents may indicate different Rheem air conditioner problems. For example:

• A burning or electrical smell may mean an electrical component in your system is malfunctioning. Call a professional for help.
• A moldy or musty smell can mean there’s mold growing somewhere in your system. Read our guide for cleaning up mold in your home. You may consider hiring an HVAC contractor or duct cleaning company, especially if you live in a humid area.
• A fishy or rotten egg smell may suggest there’s a dead animal trapped somewhere – likely in your ducts or your condenser. If you can’t find and remove the animal on your own, an HVAC technician can help.
• A skunky or gassy smell can signify a gas leak in your system. Turn it off immediately, open your windows, and call a professional.
• A sweet chemical smell likely means your refrigerant is leaking. Turn your HVAC system off, open windows for ventilation, and call an expert to find and repair the leak.

Rheem AC is making loud noises

It may be a DIY fix if you hear a rattling or clinking sound. Turn off the power and remove the cover from your compressor (you might need a screwdriver to do this). Clear any debris inside, such as sticks, leaves, or grass.

Look for loose screws that may have fallen inside, especially around the blower motor (wheel-like piece). Check and tighten any screws and bolts to ensure they’re not the source of the noise. Replace the cover and see if this stopped the noise.

Check your ducts for leaks or blockages if you hear hissing or whistling. Remove your registers and look in with a flashlight. Remove visible items that have fallen in and repair holes with duct tape. Call a duct maintenance company for service if you can’t access all your ductwork.

Screeching, banging, or other noises may indicate a more serious Rheem air conditioner problem. Call an expert for assistance.

Rheem AC is leaking water

Your AC makes some condensation. A drain pan below the evaporator coil (large indoor unit) collects the condensation. But, if you see a large puddle or dripping water, you may have a problem.

First, turn off the power to the air conditioner at your electrical box. Examine the drain pan. Soak up the excess water with an old towel and clean out any debris or mold that may be causing it to overflow.

Next, check the drain line (clear tubing) leading to the drain pan. You can pull this off and clean it if there are visible blockages. You can either use a shop vac to suck out the obstruction or flush it out with warm water. Return the drain line once it’s clean.

Rheem AC troubleshooting resources

Rheem has a page on its website that gives some information on addressing Rheem air conditioner problems. It also has a Homeowner Resource Center to look up warranty and parts details.