Although your Honeywell rht230b thermostat is designed to have a long life without problems, it could, like most digital devices, sometimes stop working. Now that your rht230b has stopped working, you want to troubleshoot and fix the issue yourself.  But you probably wonder how you should do it and whether it is even possible to do it yourself. 

The most common issues with a Honeywell rth230b are a blank display or an inactive thermostat.  These issues are generally caused by incorrect settings or dead batteries and can be troubleshot by yourself. A thermostat reset will most probably solve the problem.    

Honeywell RTH230B 5-2 Day Programmable Thermostat

In this article, we’ll discuss some common causes that might be the reason that your Honeywell thermostat has stopped working. We’ll also offer tips and guidelines on how to fix the issues that you may find. 

First two troubleshooting steps to take

The following two steps are recommended as the starting point of your troubleshooting process when the thermostat is not working.   

Step 1 – Resetting your Honeywell rth230b thermostat

Whatever the issue is that causes your Honeywell thermostat not to work, there is the possibility that resetting the thermostat might solve the problem. To reset your thermostat should be the first step to take when trying to get your thermostat working again.   And if you are successful with this step, you will save yourself lots of time for looking for problems that don’t exist!

Like most electronic devices your Honeywell thermostat might kick back into shape after being reset. Some HVAC technicians even recommend that you reset your digital thermostat every once in a while. 

Whenever the temperature in your house is not regulated as good as before, it is good to reset your thermostat. This can prevent larger future possible problems.  

How do I reset my Honeywell rth230b thermostat?

You can reset your Honeywell thermostat by power cycling. In other words, put it off completely, wait 10 to 15 seconds and put it on again.  The best way to power cycle the rth230b thermostat is to remove the batteries and put them back again after 10 seconds.  When the thermostat comes online again, press “hold.”

Step 2 – Check the inside of the Thermostat

When your heat or air conditioning suddenly doesn’t turn on anymore, it might be that there are some issues on the inside of your Honeywell rth230b thermostat. If you’ve already reset your thermostat and the problem still persists, you have to check the inside of your thermostat. 

Before you open the thermostat, turn off the electrical circuit breaker that controls the thermostat.  Also, ensure that the thermostat self is turned off.  Then remove the thermostat’s cover and check the wiring inside. 

While it is open, remove all dust and grime with a soft brush or canned air. After you’ve cleaned everything check all the wiring and fasten any loose connections. Then replace the cover and put the power on again. 

If the thermostat is still not working, you will have to troubleshoot further. 

Troubleshooting for specific problems

The issue you are encountering with your thermostat falls in one of two categories. It can either be that there is no display on your Honeywell thermostat, or the display is active but the thermostat is not working.

No Display on Your Digital Honeywell Thermostat

A blank screen is one of the most common issues of digital thermostats like the Honeywell rth230b. A blank screen means you have no display and can’t use the thermostat. 

One reason may be that the batteries are dead. If that is the case, replacing the batteries with new ones will solve your problem. 

Another cause can be that an access door on your HVAC system isn’t completely closed. Units sometimes have a switch that activates the system only when the door is closed completely. If an access door is not completely closed, the system won’t start working. This automatically cuts the power to your thermostat. Ensure that all access doors are closed – it might solve your problem.

You will also have a blank display on your thermostat when the circuit breaker has tripped. As HVAC systems generally have a separate circuit breaker, it is easy to check whether it has tripped or not. Switch it on again to see whether the problem is solved.

Remember when you want to put on a tripped circuit breaker, you first have to click it off completely and then put it on again. 

The display is active but the thermostat still doesn’t work

Sometimes your Honeywell rth230b has an active display but your thermostat still isn’t working. You normally detect that your thermostat is not working if your home feels too hot or too cold for the temperature that is displayed on the thermostat. 

Malfunctioning of a sensor

This problem can be due to a sensor that is not working anymore. To verify whether a broken sensor might be the problem use a thermometer and measure the temperature where the thermostat is located. If the two readings don’t match, the chances are good that it’s a malfunctioning sensor that is causing the problem. If the sensor can’t be replaced, you may need to replace the whole thermostat.

Incorrect settings

Other issues that can occur include incorrect day and time settings and incorrect jumper settings. If you’ve experienced power outages in your area the clock and day of the week settings are most probably not set correctly anymore. This can cause your thermostat not to work. 

You must also check that your jumpers are set to the correct settings for your HVAC system.


Few things can irritate you more than an HVAC system that is not working. And normally it is the thermostat that is malfunctioning. Even if you have an excellent thermostat like the Honeywell rth230b digital thermostat it might stop functioning at any time. Fortunately, in most instances, the fault can be found during your troubleshooting process and rectified. It is not necessarily needed to replace the thermostat.  


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