Programmable Thermostats

Reviews of digital programmable thermostats

Honeywell RTH6350

Honeywell RTH6350

Click here for the Best Price for the Honeywell RTH6350 5+2 Programmable Thermostat


  • 5+2 programming (1 slot for weekdays and 1 for weekend)
  • 4 periods per program (wake, leave, return, sleep) with option to skip periods
  • Push button programming
  • Smart response
  • Temporary hold
  • Back light digital display
  • Energy saving default settings
  • Can cycle fan
  • Armchair programming
  • Accurate to +/- 1 degree Fahrenheit
  • Keep settings even after power outage
  • Energy Star approved
  • Runs on 2 AA batteries
  • 1 year warranty
  • Price about $47


  • Air-con, heating only, cooling only, hot water, steam or gravity, 750 Millivolt system, gas fireplaces.
  • Single and multi stage heating and cooling. Heat pumps with or without auxiliary.

Review of the Honeywell RTH6350 5-2 Programmable Thermostat

The Honeywell RTH6350 combines many of the best points of the Honeywell RTH series with the simplicity and cheap price of a 5+2 thermostat. Although the Honeywell costs more than other 5+2 thermostats such as the Lux Products TX1500E it is a good option for a first time user of a digital programmable thermostat.

Honeywell promises that you can install the RTH6350 within 15 minutes. This might be an exaggerated sales claim, but the unit is certainly simple to install, especially in homes with standard wiring. Moreover, Honeywell has the best programming system. The user is presented with a set of simple menu options, rather like an ATM, that guides the user through the program set up.

A 5+2 programmable thermostat is limited to two programs. One is for weekdays and one is for the weekend. It means that if your schedule changes during the week, or you tend to go to bed at different times on Friday, Saturday or Sunday then the Honeywell RTH6350 will not be able to efficiently control the heating or cooling of the home so as to maximize savings on bills.

The Honeywell RTH6350 features smart response that uses PID technology to accurately pre-heat or pre-cool a room so that the set point temperature is reached at the start of a programmed period. This is an important function that takes the guess work at of programming and stops people turning up the heating or cooling in the belief they will make the room more comfortable quicker.

The display of the thermostat has a back light that comes on every time a button is pressed. This means buttons need to be pressed twice to make a change (once to activate the light and once to make the change). The display shows both the room temperature and the set point temperature.

As with all the models in the Honeywell RTH series the RTH6350 is able to retain its program settings even in the event of a power outage. Also it holds the room temperature to within 1 degree Fahrenheit of the set point temperature.

Drawbacks of the Honeywell RTH6350 5+2 Programmable Thermostat

As mentioned, perhaps the main drawback of the Honeywell RTH6350 is the fact that it only has 2 program settings. It is thus only suitable for people who vary their schedules very little.

In terms of functions, the Honeywell RTH6350 doesn’t have a vacation mode. For this you need to go up the range to RTH8500D. This function lets you the set the thermostat on a timer so the house is the right temperature for your return from vacation. It is a small annoyance for some people, for others it is a very useful function. The same can be said of auto change-over which is also missing on the RTH6350. This function detects the changing of the seasons and automatically switches between heating and cooling as required. This function is only useful at the times when the seasons are changing.

Other functions not present on the Honeywell RTH6350 but present on other Honeywell RTH thermostats are battery change and filter change warnings. It is recommended that you change the batteries once a year. Perhaps at the same time every year so you don’t forget. A similar regime should be set up for changing the HVAC filters.

An important drawback of the this Honeywell thermostat as with all the Honeywell thermostats in the RTH range is that it keeps the room temperature within 1 degree of the set point. It doesn’t have a swing control setting like thermostats by Lux Products and Hunter. In extreme weather what might be seen as a sign of an accurate thermostat in facts becomes a problem as the heating/cooling cycles several times every hour. This is called short cycling and can cause damage to HVAC systems.

Comparison with the Lux Products TX1500E

The Lux Products TX1500E is a cheaper thermostat and it is a more powerful thermostat in that it has a program slot for both Saturday and Sunday (5-1-1). The Lux Products TX1500E also has a programmable vacation mode that could also be used as an extra program slot – thus making it an 5-1-1-1 device.

The Lux Products TX1500E has smart response and temporary hold like the Honeywell RTH6350 but also has a keyboard lock out. The display on the Lux Products TX1500E also shows the relative humidity in a room.

The main advantage of the Honeywell RTH6350 has is that it is very easy to install and program. Honeywell is probably the most user friendly brand of thermostat.

Amazon Reviews

25 people have reviewed the Honeywell RTH6350 on Of these 25 reviewers 13 of them give the thermostat the highest score of 5 stars, 5 people give give it 4 stars, 2 people 3 stars, 3 people 2 stars and 2 people 1 star.

One reviewer complains that they thought the Honeywell RTH6350 has auto change-over. On the official Honeywell site the RTH6350D is listed as having auto change-over. It says the same thing on the box but once the thermostat is removed from its packing there is a sign saying that if auto change-over is required then the Honeywell RTH6450 is the thermostat to buy. One presumes Honeywell will rectify these mistaken claims both on its packaging and on its website.

Another issue is with nomenclature – it is hard to tell if the Honeywell RTH6350 is same or different to the Honeywell RTH6350D. They are in fact the same – Honeywell uses these names interchangeably on its website. This is another thing they need to improve about their website. Clearly any prospective buyer should do some research and read instruction manuals, links for which are provided down the right hand side of this site.

Reviews mention how easy it is to install and program the Honeywell RTH6350 and how convenient it is that program periods can be skipped. At the same time, the theme of Honeywell thermostats not having swing control comes up. One reviewer notes that the precision of the thermostat (to within 1 degree of the set point) leads to more cycling of the furnace than with other programmable thermostats. Another reviewer mentioned that the Honeywell RTH6350 is not suitable for controlling heat pumps because it turns on the auxiliary too quickly. If you have a heat pump it is worth looking at the Lux Products BBHP2110 Smart Temp for Heat Pumps. It is a 5-1-1 thermostat especially designed for heat pump management.

Keynote quotes:

“Programming literally could not be easier.”

Steve Young

“The packaging and website both claim that the 6350D has auto changeover from heating to cooling. However, that is NOT the case.”

Daniel Miller

Sun, December 11 2011 » Honeywell, Under $50