How to Troubleshoot RTH230B Honeywell Thermostats

Honeywell's RTH230B programmable thermostat features a slim design with weekday and weekend programming. This means you can set the thermostat to operate differently through the week and on weekends. It also has a feature that allows you to program the thermostat to an energy saving program. Honeywell programmable thermostats are easy to use, as often the thermostat's display screen will help to walk you through its features. Troubleshooting your Honeywell thermostat is a simple task that might save you a repairman's bill.

Modifying the Schedule

Step 1

Press the button labeled "Pgm." The settings for time period one will display.

Step 2

Skip a time period by pressing "CLR" while the period is displayed.

Step 3

Select the program you wish to modify using the "Day" button. The days of the week will appear when the Monday-Friday program is selected. Saturday and Sunday are displayed when the weekend program is selected.

Step 4

Press and hold the day button for three seconds to select all seven days.

Step 5

Set the time using the time buttons on the thermostat. It will adjust in 15 minute increments.

Step 6

Press the button marked "P#" and the heating or cooling set point will flash depending on the position of the Heat/Cool selector.

Step 7

Set the temperature you desire for the displayed time period using the temperature buttons displayed.

Step 8

Switch to the opposite mode (heat or cool) by moving the heat/cool selector switch to set the desired temperature in that mode.

Step 9

Press the "P#" button to continue to the next time period.

Step 10

Repeat these steps for each period you wish to modify, then press the "Exit" button to save changes.

Step 11

Set the thermostat to programmable mode in order to use the schedule you've programmed.

Cooling Mode Not Starting

Step 12

Wait up to five minutes for cooling to start. This is a safety feature programmed into the thermostat for the compressor.

Step 13

Check the display screen if cooling does not begin after five minutes.

Step 14

Look for the battery icon. If it is flashing you need to change the thermostat's batteries. The icon will flash for 120 days, then the thermostat cuts power to the heating and cooling unit.

Step 15

Turn the thermostat to "Off" and remove the thermostat cover.

Step 16

Remove the old batteries located along the top of the thermostat. Replace them with two new AA batteries. Replace the thermostat cover and adjust the time of day on your thermostat. The temperature settings will remain when you change the batteries.

Thermostat Isn't Following the Pre-Programmed Homes Program

Step 17

Look at the thermostat's display screen. If there is no house picture on the bottom left of the screen, then it is not set to a homes program.

Step 18

Press the mode button once. The house icon should appear, indicating that the thermostat is following the homes program.

Step 19

Check that the thermostat is set to programmable mode if the house icon doesn't appear, and press the mode button again.

Icons Flashing

Step 20

Replace the batteries if the battery icon flashes. The icon should disappear when this is done.

Step 21

Replace your heating and cooling system filter after 500 hours of operation. The filter icon will automatically flash when the system has reached 500 hours of operation.

Step 22

Press the button labeled "Filter" and hold for three seconds when you've replaced the filter. The icon should disappear and the counter will reset.

Fan Runs/Will Not Run Continuously

Step 23

Find the small button labeled "Auto/On" and "Fan" located on the bottom of the thermostat.

Step 24

Switch the button to "Auto" to make it run in cycle with your heating and cooling system.

Step 25

Switch the button back to "On" when you want the fan to run continuously.