Swing Control on Programmable Thermostats

One of the most important functions on a good digital programmable thermostat is swing control. This post will look at what swing control does and also attempt to explain how the Honeywell alternative to swing control works.

Swing control can be adjusted normally in 0.25 degree Fahrenheit increments. It is a function that allows the user to set up a range around the set point temperature within which the thermostat does not activate the heating or cooling. So for example if the set point is 75 degrees and the swing is set to 4 (1 degree) then the heating will not be activated by the thermostat until the temperature falls below 74 degrees.

Swing control is useful because trying to maintain an exact room temperature can often mean the heating or cooling is turned on and off in rapid bursts. This is called short cycling and it can damage furnaces and other HVAC equipment.

Swing control is found on all Lux Products programmable thermostats and Hunter programmable thermostats. It is absent, however, from Honeywell thermostats. This absence is peculiar because Honeywell thermostats are Energy Star approved and usually designed and built to high specifications.

Instead of swing control Honeywell thermostats such as the RTH8500D, RTH7600D and the RTH7500D allow the user to set the cycles per minute for heating and cooling separately. This function is pre-set at 5 on these devices and has to be changed in accordance with your particular HVAC systems. Thus, a hot water system that uses radiators needs a longer cycle so a setting of 3 should be chosen. Whereas an electric wall heater that quickly warms a room needs a shorter cycle and should be set to 9. Using the wrong cycle settings can damage your HVAC equipment.

The only problem with the Honeywell alternative to swing control is if a home is poorly insulated or the temperature is extremely hot or cold. If the set point temperature is 75 degrees then the heating will cut off at 74 degrees. The idea is that the residual heat will nudge the temperature up to 75 degrees. If it doesn’t then the heating will constantly cycle on and off to try and reach the desired temperature of 75 degrees. This is a common complaint about Honeywell thermostats.

In conclusion, Honeywell thermostats only work well in well insulated houses and in temperate weather zones. If you live in the tropics or in cold northern (or southern climes) you should consider getting a Lux Products or Hunter thermostat instead.