Programmable Thermostats

Reviews of digital programmable thermostats

Honeywell RTH230B

Honeywell RTH230B

Find the best price for the Honeywell RTH230B 5+2 Programmable Thermostat


  • 5+2 programmable thermostat with 4 periods per day
  • Large display with soft touch button interface
  • Temporary hold
  • Continuous or automatic fan modes
  • Accurate to +/-1 degree Fahrenheit
  • Display in Fahrenheit or Celsius
  • Battery change warning
  • Filter change warning
  • Energy Star approved
  • Dimensions: 1.8 x 6.5 x 8.8 inches
  • Price: $27


  • Central gas, oil or electric furnaces, air-con, millivolt systems
  • 1 stage heating and 1 stage cooling

Review of the Honeywell RTH230B 5+2 Programmable Thermostat

The Honeywell RTH230B is one of Honeywell’s most affordable programmable thermostats. They have pared down the functions on this thermostat to deliver the reliability of a Honeywell thermostat but at a very attractive price.

The Honeywell RTH230B has 1 program setting for weekdays and 1 setting for the weekend. This will suit families who have 1 schedule for week days and another for the weekend. The problem with the 5+2 is that on Sunday you might want the heating or cooling to come on later if you enjoy a lie-in but unlike Saturday night you might want to return the evening setting to the same as the weekday because you go to bed early to prepare for the following week.

Both of the program slots are divided into 4 sections that represent morning, afternoon, evening and night. By adjusting the start and stop times and temperatures for these periods of the day you make savings on your heating and cooling bills. This is what the Honeywell RTH230B can do as well as more expensive programmable thermostats. By being able to program the heating / cooling for different times of the day you no longer have to rely on manually making changes before you go out or go to bed. It is forgetting to manually adjust a normal thermostat that causes homes to be carbon inefficient. By just setting back the thermostat temperature 1 degree for 8 hours you save 1% in fuel bills for that 24 hour period.

This programmable thermostat is the same as other Honeywell thermostats in that it keeps the room temperature within 1 degree Fahrenheit of the set temperature. Honeywell thermostats don’t have swing control. Rather they limit the number of cycles per hour to prevent damage to the HVAC systems. For homes that are adequately insulated this system works well and makes a home comfortable. For homes with poor insulation or located in an area that has very hot summers and / or very cold winters the Honeywell alternative to swing control can have mixed results. The Honeywell system allows the user to set the number of cycles for cooling or heating per hour. See the post concerning swing control.

The only function on the Honeywell RTH230B is a filter change warning. After so many hours the thermostat flashes a warning to tell you to replace the filters. This saves you further money as it guarantees the HVAC equipment is running at its most efficient. The other thing to remember to do is to get a HVAC tune up every couple of years.

This programmable thermostat is straight forward to install and comes with clear instructions. In case you lose the instructions we have provided a link down the right hand column for the RTH230B user’s manual. This thermostat runs on batteries that are inserted into the front of the device. It cannot run off mains electricity.

The thermostat is also a cinch to program. It takes very little time to program because there are only 2 programs to set up. Thought should be given as to how these 2 programs are arranged. For people with more complicated lives a 5-1-1 thermostat or a 7 day thermostat is more suitable.

Programming is through soft touch buttons on the front of the thermostat. The simplicity of the user interface is considered a big plus by most users.


As discussed, one of the drawbacks with this thermostat and with other Honeywell thermostats is the lack of a swing control function. Opinions greatly vary as to the wisdom of the Honeywell approach to balancing the desire to keep within the set point and to also prevent the heating or cooling continually cycling on and off.

Another issue is the lack of a backlight on this model. While many people will simply set the thermostat and forget it, others like to refer to the device even at night time to check the temperature and possibly the time.

The Honeywell RTH230B programmable thermostat also lacks useful functions such as auto change over that allows for days when both heating and cooling might be required. It also lacks smart response that tracks heating / cooling times and finds the optimum time needed to bring a room to the desired temperature prior to the start of a programmed period. This means always waking up and getting home to a comfortable living area.

Honeywell RTH230B vs. Lux Products TX500E

For those people who want more functions in the same price range the Lux Products TX500E is also a 5+2 device but includes temporary hold, vacation mode, keyboard lockout and swing control. Moreover, the TX500E has adjustable swing control and a backlight.

Honeywell RTH230B vs. Hunter 44550

For another $10 or so a home owner can get the Hunter 44550. It is Energy Star approved and has 7 day programming as well as all the most useful functions such as swing control, temporary hold, smart recovery (same as smart response), auto change over, vacation mode, filter warning and armchair programming.

Honeywell RTH230B vs, Honeywell RTH2310B

The Honeywell RTH2310B is also a 5+2 programmable thermostat. It costs about $29. For the extra $2 the model includes a blue backlight

Amazon Reviews

The Honeywell RTH230B has received 83 Amazon reviews, of those 30 are maximum 5 star reviews; 20 people give the device 4 stars; 8 people give it 3 stars; 11 2 stars; and 14 1 star. Opinions are thus fairly divided on this thermostat.

One reviewer complained that the instructions told him to remove the jumper wire and the thermostat wouldn’t control the furnace. It turns out the jumper wire should be connected.

Another criticism was that the battery cover would be better off on a hinge rather than snapping on and off.

On a positive note people commented that the RTH230B is easy to program and the temporary hold or override is just a matter of putting the temperature up or down.

Keynote Quote

“If you’re in the market for a new thermostat, this is a nice simple unit, affordable, and easy to use.”

– Wiseguy 945

Fri, June 1 2012 » Honeywell, Under $30