What does 54NC mean when displayed on my Honeywell room thermostat?

Centigrade?

HONEYWELL WEBSITE:
Go to honeywell.com
Under red welcome sign
Bottom red highlighted box literature/image search
Type in thermostat model number
Click on arrow to right
Then click on the PDF files owners manual / installation instructions
If you can’t find what you want, the bottom left and bottom of web
Page, they have homeowners assistance and Home products to get the help you need.

What does error code 6Af Lo mean? (the f is upside

Hi,
If the thermostat is not over shooting the temperature than don't worry about it.
These thermostats are very sensitive and will turn the heat back on even before the degrees drop on the display. Often they will shut down before the display changes also. You can change the sensitivity of the thermpstat if you read the directions and change the cycles per hour to a less number. There is an installers program in there that you need to push a combiunation of buttons to get too. The instructions tell you how to do that also.

Hopefully you did not throw away the instruction manual for your t-stat.. :-)

Heatman101

If it is just a heater,it means no power.

I am a honeywell dealer and this stat is obsolete and no longer supported. I am not able to pull any info on this. It might be time for a new one.

the cover pulls off if it has a green screen then most likely takes batteries if does not light up then no batteries with a small piece of insulated wire jump from green to red if indoor fan does not come on then transformer bad

Mike, The static electrical spark probably 'zapped' the Rth230b Honeywell Display unit. If you have already tried removing the power (batteries) from the unit and after waiting several minutes; reapply the power (batteries). If the problems remain unchanged, then it is time to replace the Display unit with a new one. The static electricity problem is problematic and the only way to prevent the same problem from recurring is to discharge yourself before touching the Honeywell Display. As you walk across the room which (probably has carpet), causes the static electricity to build up on your body and then discharges itself through the Display unit when you make contact with the Display unit. You might try coming to a complete stop and attempt to discharge the static charge on your body by touching the wall first with one hand for a second before touching the Display unit with the other hand. Naturally, cold weather with low humidity makes the static electricity worse. Hopes this helps you. Henry

If you need further help, I’m available over the phone at https://www.6ya.com/expert/henry_239f63a136de60f0

It is not adjustable, sounds like the LED is going bad. Tstat has battery back up for power outages. If you slide the fan switch from auto to on does the blower motor start? If not control problem with unit.

That flame means that you heat is on and working .
Th