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HomeRepair HelpMars Central A/C RepairMars Central air conditioner wall thermostat not working properly Repair
Mars Central air conditioner wall thermostat not working properly
If your Mars central air conditioner thermostat is not working, the thermostat itself is the most likely problem. A failed wall thermostat may have a blank display, fail to communicate with the furnace or air handler, or stop sending the 24-volt signals that turn the air conditioner on and regulate your home's temperature. If the display is dead, check the wall thermostat batteries, since many models use replaceable batteries. If batteries are not the cause, the Mars thermostat may need replacement. A failed control board in the furnace or air handler can also interrupt power to the thermostat, while a tripped circuit breaker, blown fuse, or switched-off power supply can make the thermostat appear inoperative. Damaged or loose thermostat wiring can prevent signals from reaching the indoor or outdoor unit and may cause an AC thermostat not working or central air thermostat not working symptom. Battery replacement and visual wiring checks are reasonable DIY steps, but testing 24-volt circuits with a multimeter requires care, and any 120/240-volt diagnosis should be handled by a qualified technician. Enter your model number to find the exact Mars replacement thermostat, control board, fuse, or other part for your specific central air conditioner.
01 - Mars Central Air Conditioner Wall Thermostat
The wall thermostat is responsible for controlling components and regulating the home's temperature. The thermostat can be powered with 24 volts from a control board on a separate unit like a furnace or air handler, or from batteries in the thermostat itself. The thermostat also has terminals to receive and distribute low voltage 24 volt power to run different HVAC products such as a furnace, air conditioner, or heat pump. If the wall thermostat is receiving power but the display is dead, or it will not send power out in the appropriate modes, the wall thermostat will need to be replaced.
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Highly Likely
02 - Mars Central Air Conditioner Wifi Thermostat
The WiFi thermostat is responsible for controlling components and regulating the home's temperature. The thermostat is usually powered with 24 volts from a control board on a separate unit like a furnace or air handler. The thermostat also has terminals to receive and distribute low voltage 24 volt power to run different HVAC products such as a furnace, air conditioner, or heat pump. If the WiFi thermostat is receiving power but the display is dead, or it will not send power out in the appropriate modes, the WiFi thermostat will need to be replaced.
Highly Likely
03 - Wall Thermostat Batteries
Most wall thermostats are either powered by an enclosed battery or by the furnace or air handler control board. If the thermostat display is dead, you can remove the thermostat cover and look for replaceable batteries. Replace the batteries if needed and check operation.
Common
04 - Mars Central Air Conditioner Control Board
The control board regulates the power supply to all of the components in the system. If the control board fails, it might not send voltage to the thermostat, leaving the thermostat inoperable.
Less Common
05 - Incoming Power Problem
Check to see if there is power to the furnace or air handler. One or more indicator lights on the control board should be illuminated. If there is no power to the furnace or air handler, check to see if a circuit breaker has tripped or a fuse has blown. Confirm the power switch on the side of the unit is turned on.
Less Common
06 - Bad Wall Thermostat Wiring
In order to send signals from and to the indoor and/or outdoor units, the wall thermostat uses a group of wires usually called thermostat wiring. If the thermostat wiring gets damaged, certain functions of the system or the thermostat itself may not function properly. The thermostat wiring can be checked for power or continuity with a multimeter. The wiring is usually industry standard colors: Red/White/Yellow/Green for a four-wire system.
Less Common
Frequently Asked Questions
Why is my Mars central air conditioner thermostat not working?
Why won't my central air conditioner turn on from the thermostat?
How do I test a central AC thermostat wiring?
Should I replace the Mars wall thermostat or the control board?
How do I find the correct replacement thermostat for my Mars central air conditioner?
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