Honeywell Thermostat RTH230B Not Working? (Possible Causes & Fixes)

Nick Durante
by Nick Durante

The Honeywell RTH230B is easy to use, and it works reliably most of the time. Thermostats of any kind can quit working optimally or at all at the most inconvenient times, and they can be tricky to troubleshoot. So, what does it mean when your Honeywell RTH230B isn’t working, and what should you do?

Honeywell RTH230B thermostats stop working when the breaker trips, a fuse blows, and the batteries die. Clogged air filters cause a Honeywell RTH230B to stop working entirely or increase heating and cooling bills. Reset your circuit breaker and replace blown fuses after electrical surges or power outages to fix your Honeywell RTH230B thermostat.

You can also remove your thermostat’s batteries for 10-15 seconds and put them back in to reset your RTH230B. Troubleshooting your Honeywell RTH230B takes little to no time, and you can use this guide to identify your problem. Let’s take a look at what causes a Honeywell RTH230B to stop working and see what you can do to fix it.

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Possible Causes

Honeywell makes some of the best thermostats on the market, and the RTH230B is no exception. Their thermostats are easy to use, energy-efficient, and generally run without incident. Even still, there are several possible causes for a Honeywell RTH230B that simply is not working properly.

Batteries Dying

Any thermostat can start to behave oddly when its batteries are dying, and that includes the Honeywell RTH230B. Of course, thermostats like the RTH30B won’t work at all when the batteries are dead. Batteries can last in newer Honeywell thermostats for up to 1 year, or longer depending on usage.

However, homeowners have to change thermostat batteries every 10 months on average with heavy use. The Honeywell RTH230B takes two AA batteries, and the thermostat face displays a low battery message. Watch out for a glowing “low battery” icon that can indicate your batteries are on their last leg.

Breaker Tripped

Thermostats stop working when the circuit breaker trips, and that includes the Honeywell RTH230B. Circuit breakers trip when you have too many things plugged in on one circuit or if there is a power surge. Heavy storms can also cause a circuit breaker to trip, and your RTH230B may not work when the power comes back on.

Blown Fuse

Fuses can blow during electrical surges or power outages, and it will prevent your Honeywell RTH230B from working. Sometimes, fuses will blow as a safety precaution if your air filter is dirty so that it doesn’t cause further electrical damage. Inspect your circuit breaker after a power surge and look for blown fuses before you reset the breaker.

Blown fuses are easy to spot because they are generally damaged and blackened or dirty looking. Inspect your air filter if you get a blown fuse for no obvious reason because it can indicate that you need to replace it as well.

Clogged Filter

It is best to replace a clogged air filter before it causes a blown fuse. Thermostats such as the Honeywell RTH230B cannot work properly when the air filter is clogged and overdue for a replacement. Dirty air filters can cause a spike in electric bills, an ineffective thermostat, respiratory problems, it can weaken your heat exchanger.

Air conditioners and furnaces will often shut off shortly after kicking on when the filters are dirty. That is often a telling sign that your air filter is clogged, and it is time to replace it. Waiting too long to replace a clogged air filter can decrease the quality of your air over time, and it will reflect in your bills as well.

How To Fix Honeywell RTH230B

Builder-owners and DIYers can troubleshoot and fix a Honeywell RTH230B on their own, in most cases. Simple problems like tripped circuit breakers and clogged air filters come with a quick fix. Let’s take a look at how you can fix the most common problems that you can run into with a Honeywell RTH230B.

1. Replace Batteries

Countless homeowners can fix their Honeywell RTH230B by simply replacing the batteries. All that you need to do is swap out the dead or dying batteries with two new AA batteries to get back up and running. Batteries generally last 10-12 months in a Honeywell thermostat.

Wait 5 minutes to allow your Honeywell RTH230B a delay period after you change the batteries before it will run perfectly. This short delay period often occurs when a thermostat loses power, gets new batteries, or detects uneven pressure in the compressor. The brief delay time gives the compressor time to balance out the pressure as a safety precaution.

2. Reset Circuit Breaker

Circuit breakers can trip due to power outages, surges, blown fuses, and clogged air filters. Reset your circuit breaker if it went out due to a surge or power outage. Push the lever to “off”, then push it over to the “on” position.

Check to make sure that there are no blown fuses before you reset your circuit breaker. Your Honeywell RTH230B and other electronics on that circuit should run like normal after that. Otherwise, it can be a sign that you have a short circuit or more severe electrical problem that an electrician needs to look at.

3. Replace Fuse

Replace blown fuses to get your Honeywell RTH230B back in working order. Take a look at your air filter first to see if it is dirty because that may have caused your fuse to blow. Otherwise, it is safe to replace a fuse if it blew after a surge or power outage.

Flip your circuit breaker switch to “off” and carefully pull the blown fuse out. Unscrew the blown fuse by hand or with a screwdriver and remove the wires from it. Remember where the wires need to go and attach them to the new fuse.

Screw the new fuse into place, make sure the wires are secure and pop the fuse into its housing. Turn the circuit breaker back on and close the cover. Your circuit breaker will work unless there is another problem.

4. Replace Filter

Remove your air filter cover and inspect it for dirt, dust, and debris. Replace your filter if it is dirty and affecting your thermostat’s performance and the quality of your air. You can easily pop air filters out of place and put another one in.

Your new air filter will work as long as you put it in tightly and make sure that the air is facing the unit. Honeywell RTH230B thermostats work best with new, clean air filters. The results will manifest in your air quality, energy bills, and thermostat function.

5. Reset Thermostat

Reset your Honeywell RTH230B if there is no clear reason that it is acting up. Inspect your air filter, circuit breaker, fuses, and batteries to make sure they are not the problem. If they aren’t then all that you need to do is reset your thermostat.

Simply remove the batteries from your RTH230B, wait 10-15 seconds, and put the batteries back in. Wait for the display to reappear and hold the MODE button to reset it. You can always try to reset your Honeywell RTH230B before troubleshooting it for a quick fix.

Related Questions

Can I replace my thermostat with any thermostat?

You cannot replace your thermostat with any thermostat, but many modern thermostats are compatible with several systems. It is possible to replace analog thermostats with smart thermostats, but additional electrical work is required. Some homes have separate systems for heating and cooling, and that can make it hard to replace a thermostat.

Do Honeywell thermostats go bad?

Honeywell thermostats go bad in an average of 10 years, but it depends on usage and condition. It is rare for any thermostat to last longer than 10 years, and they can go bad before then. Energy bills increase, air quality becomes poor, and your thermostat is inaccurate when it starts to wear out.

Should my Honeywell thermostat be on auto?

Set your Honeywell thermostat to auto to lower energy bills, reduce humidity in your home, and preserve your air filter. The fan setting on your Honeywell thermostat controls whether your AC fan runs continually or automatically.

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Summing It Up

Inspect your air filter and replace it if your Honeywell RTH230B is not working. Replace your batteries with two AAs if they are dead or the display indicates they are low. Reset your circuit breaker after an outage or power surge.

Inspect your circuit breaker for blown fuses and replace them to restore power to your RTH230B. Reset your Honeywell RTH230B by removing the batteries for 10-15 seconds then press the “MODE” button to reset it.

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Nick Durante
Nick Durante

Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.

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