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HomeRepair HelpLennox Central A/C RepairLennox Central air conditioner has poor temperature control Repair
Lennox Central air conditioner has poor temperature control
When a Lennox central air conditioner has poor temperature control, uneven cooling in the house, or an AC temperature that is not accurate, start with the air filter. A clogged filter restricts airflow through the furnace or air handler, reduces cooling capacity, and can cause the evaporator coil to frost over. Replace it as needed, especially in dusty homes or homes with pets. Next, check the wall thermostat. Failed electrical contacts can prevent the furnace or air handler and condensing unit from operating consistently, causing the AC not to hold temperature. A multimeter continuity test can help identify a defective thermostat. Also inspect vents for blockage or leaks, since poor duct airflow can create room-to-room temperature differences. If the system cools quickly and shuts off before air circulates evenly, an oversized air conditioner may be the cause and requires HVAC evaluation. Enter your Lennox model number to find the exact replacement air filter or thermostat for your system. Turn off power before servicing, and leave 240-volt wiring, the condensing unit, and any sealed-system or refrigerant work to a licensed HVAC technician with EPA 608 certification.
01 - Lennox Central Air Conditioner Air Filter
Check and replace the air filter at least twice a year, more often in dusty/dirty environments or if there is a pet in the home. A clogged air filter will greatly reduce the air flow of the furnace or air handler which can result in poor temperature control when trying to heat or cool the home.
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Highly Likely
02 - Lennox Central Air Conditioner Wall Thermostat
The wall thermostat has electrical contacts that control the power supply to the furnace or air handler and condensing unit. If the contacts in the thermostat fail, certain components of the cooling system may not work or may only work intermittently. To determine if the thermostat is defective, use a multimeter to test it for continuity. If the wall thermostat does not show proper continuity, replace it.
Common
03 - Lennox Central Air Conditioner Wifi Thermostat
The WiFi thermostat has electrical contacts that control the power supply to the furnace or air handler and condensing unit . If the contacts in the thermostat fail, certain components of the cooling system may not work or may only work intermittently. To determine if the thermostat is defective, use a multimeter to test it for continuity. If the WiFi thermostat does not show proper continuity, replace it.
Common
04 - Clogged Air Filter
If the air filter is clogged, air cannot flow properly through the home's venting system. This greatly reduces the cooling capacity of the air conditioner. In addition, if the air filter is clogged, the evaporator coils will frost over and not be able to remove moisture from the air. The air filter should be checked and replaced at least twice a year, more often in dusty/dirty environments. Refer to owner's manual for guidance.
Less Common
05 - Blocked or leaking vents
The furnace or air handler must have good airflow to work properly. A blocked or leaking vent can prevent good air flow and cause inconsistent room temperatures.
Less Common
06 - Oversized air conditioner
An oversized furnace or air handler will quickly heat or cool the home and shut off. This causes acceptable temperatures in certain areas but not in others. The circulated air needs time to distribute evenly throughout the home; the air recirculating through the furnace or air handler for longer periods of time will produce better results.
Less Common
Frequently Asked Questions
Why does my Lennox central air conditioner have poor temperature control?
Can a clogged air filter cause my central air conditioner to not cool evenly?
How do I test a Lennox thermostat that is not holding temperature?
Could an oversized central air conditioner cause uneven cooling or poor temperature control?
How do I find the correct Lennox central air conditioner replacement part?
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