How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask airheatman Your Own Question
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8165
Experience:  Furnace, A/C and heat pump specialist.
Type Your HVAC Question Here...
airheatman is online now
A new question is answered every 9 seconds

I am looking to replace a white rodgers thermostat f80-51.

This answer was rated:

I am looking to replace a white rodgers thermostat f80-51. The digitial screen always states it needs a battery, though I have bought and replaced the batteries 3 times to insure batteries are good. The unit is working but it is difficult to program as the numbers are not clear.
Hello. My name is XXXXX XXXXX I'll do my best to help. Troubleshooting often requires meters and test equipment. Let's get started and see what we can do.
The F80-51 can be used with numerous systemsStandard heat/cool or heat only systems
• Electric heat systems
• Gas or oil fired systems
• Gas systems with intermittent ignition devices (I.I.D.)
and/or vent dampers
• Hydronic (hot water or steam) systems
• Single-stage heat pump systems
• Millivolt systems.
Do you know what type of system you have? If not if you can provide model numbers on indoor and outdoor unit. I will be able to help you figure it out and make a recommendation
Customer: replied 3 years ago.
I have gas heat and air conditioning one unit on roof . This thermastat was installed in 2000 and has worked fine until the unit requested battery replacement. Unit is still working.
The seven wires is unusual for a gas system. Can you tell me what these 7 wires connect to (which terminals)?
Customer: replied 3 years ago.
will be difficult but i will go to thermostat and try to figure it out. so give me a few minutes . I know coming from the wall are only wires not a plug which the handy man today was surprises. So he doesnt know what to to do. I will be right back
Yes, there will be no plug, The wires connect to terminals such as Y,R,G,W etc
Customer: replied 3 years ago.
i just took a picture, give me a moment and may be able to attach or if you have an email will send it wright away
You can upload the pictures using the tiny pic site .
Here is a link to the site.

Click on Browse , select the file from your folder.then click UPLOAD NOW.

They will give you a quote to enter in the box to verify you are a human.Enter the quote and click UPLOAD NOW

You will see your picture on right side of screen.

Then copy the link URL for email & IM

Paste that link here on the site.
Customer: replied 3 years ago.
will try to do tiny pic now.
Great Standing by
Customer: replied 3 years ago.
of course, tried it and it failed . I will try again
Standing by. Are all 7 wires connected?
Customer: replied 3 years ago.
All wires are connected. I have nothing but change the battery .perhaps I can explain the wires? i seem to be failing at this photo thing. also i just want to buy a new one and replace it but cant seem to find it anywhere. so how to explain.
Just tell me what color wire is connected to each terminal.
Example Red to R. Green to G, etc
Customer: replied 3 years ago.
ok hold on the picture uploaded . will try to copy the URL hold on
Customer: replied 3 years ago.
Customer: replied 3 years ago.
i sent the pic but there are seven terminals look like screw heads. starting at 12:00 is white. 1:00 has thin red and thick red 3:00 has (not sure) 4:00 no attachment 6:00 has red and yellow 7:00 has green 10:00 has thick red. does this help or did you get ?

Excellent.Any Honeywell, or Robertshaw single stage heat. single stage cool thermostat will work in this situation. I recommend the Honeywell RTHL2310 if you are not looking for anything fancy. It is a good 5/2 programmable thermostat and very inexpensive. Lowes sells it for around 30 bucks

Your small wires are the ones coming from unit. Larger wires in pic are part of thermostat.
On new stat: Red will go to RH with a factory jumper to RC
Green will go to G
Yellow will go to Y
White will go to W.
airheatman and 2 other HVAC Specialists are ready to help you
I see you have left the conversation. This should solve your problem and answer your question adequately. Please rate accordingly so I am credited for answering your question. If you need further assistance, I will be more than happy to assist further. Just let me know.