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Matthew, HVAC Technician
Category: HVAC
Satisfied Customers: 2014
Experience:  14 years experience in the HVAC field of service, installation, Manual J & D calculations
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I own a Totaline residential programmable thermostat #P374-1800.

Resolved Question:

I own a Totaline residential programmable thermostat #P374-1800. The unit is less than 3 yrs old. My problem is that the backlit LCD display light does not come on any more; this just started happening about 3 days ago. Can you guys give me some advice on how to correct this? I have tried using the owner's manual without any success.
Submitted: 7 years ago.
Category: HVAC
Expert:  Matthew replied 7 years ago.
IS there a keypad icon on the screen?
Customer: replied 7 years ago.
There is no keypad icon on the LCD Display
Expert:  Matthew replied 7 years ago.
ok, press and hold the mode button down and as you are holding it press teh program button to enter the setup menus. once in the menu use the mode button until you see setup 7 in the top right corner. tell me what this is set on.
Customer: replied 7 years ago.
Expert:  Matthew replied 7 years ago.
turn it to on and see if it makes a difference.
Expert:  Matthew replied 7 years ago.
The settings are auto, on, and off. The light should work even when in the off position it just only stays lite for 8 secs after a button is pushed. On is on continuously, and auto it is on continuously from 6pm-6am. This stat does not take batteries If i remember correctly so if all the heating and cooling functions of the furnace work then it is just a malfunctioning LCD.
Customer: replied 7 years ago.
I suspect a malfunctioning LCD display as well since I have checked each setting and the owner's manual for any replacement parts. This is not a "terminal" matter and the lighting is convenient for early morning or late night operation. Thank you for your input and time.
Expert:  Matthew replied 7 years ago.
I thought maybe switching from off to on may trigger a different power path somehow to the stat LCD. If it doesn't change then yeah once the LCD goes out the only way to get it fixed is a new stat.
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