What’s a too hot furnace temperature during cold Indiana winter weather? Sometimes, the programmed thermostat setting may not be sufficient to keep the house comfortably warm. The obvious next step is to bump that setting higher (and higher) for more heat from the furnace.

Or is it? The fact is, most thermostats will not even allow a setting higher than 90 degrees no matter how cold it may be outdoors and indoors. The too hot furnace temperature limit is there to prevent the furnace from running excessively long cycles and overheating, incurring damage to critical components like the heat exchanger.

In addition, most furnaces also incorporate an internal high-limit switch that can only be adjusted by a qualified HVAC technician. This device senses the temperature of internal furnace components. If the furnace exceeds the safe temperature, the high-limit switch will automatically shut off the furnace burner.

How Thermostat Setting Controls Room Temperature

No matter what the thermostat setting in the house may be, heated air leaving the furnace consistently ranges from 140 degrees up to 170 degrees, depending on the size of the unit. By the time the heated airflow enters a room through a supply vent, the air temperature has cooled by as much as 50 degrees. As the furnace airflow blends with cooler room air, the thermostat maintains the precise room temperature setting by cycling the furnace burner on and off at specific intervals.

Optimizing Thermostat Settings

The Department of Energy has researched thermostat settings for the best balance between indoor comfort, furnace efficiency, and lowest operating costs. The DOE recommends a temperature range from 68 degrees up to 72 degrees. If elderly persons are residing in the house, many sources recommend higher temperatures — up to 78 degrees.

Ask the heating professionals at Mowery Heating, Cooling and Plumbing for more about staying comfortable this winter without a too hot furnace temperature setting.