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What Is A Multi-Stage Furnace?

What Is a Multi-Stage Furnace?

A question that we get from homeowners is, “What is a multi-stage heating and cooling system?” A multi-stage system means that your gas valve and the furnace has two different stages.

Here’s an example of how a true two-stage thermostat and a two-stage furnace work.

Lets just say, for instance, you come home from work and the thermostat says 68 degrees. Now that you’ll be in the space, you want to make it 70 degrees. Depending on the way the parameters are set in the thermostat, that furnace will come on and run on, what we call a “low fire,” or first-stage heat where you are:

  • Using less electricity for the ECM fan motor inside the furnace
  • Using less gas for only running one stage of the heating
  • Bringing the temperature up in the house in a very efficient process

Lets use a 96% efficient furnace as an example. So, if you can picture one cubic foot of gas, you’re using 96% of that and you’re only wasting 4% of it.

Can You Modify a Single-Stage Furnace Into a Two-Stage Furnace?

For existing systems,  if you have a single-stage furnace, I can’t make that a two-stage furnace.

You could, however, install a two-stage WiFI thermostat control module and display on a single-stage system.

And then down the road, when you decide you want to upgrade your furnace, all that you have to do is go back into the parameters of the control and let it know that you are now operating on two-stage system instead of a single stage system. Simply set it and it’ll do it’s job.

This is one way to begin future-proofing your HVAC system a little bit at a time.

You can gain all of the benefits of a WiFi thermostat now, like getting alerts via text or email when there is something wrong, enhanced scheduling options, consolidating all heating and cooling controls into one unit, and the ability to remotely adjust the temperature from your smartphone when you’re away from your house.

Do I Already Have a Two-Stage Furnace?

A lot of times when a two-stage furnace is installed, the contractors don’t run the extra wire that is needed to put in a true two-stage thermostat.

Instead, they leave a single-stage thermostat on the wall and then they set the control board up to automatically bring on a second stage of heat whether it is or isn’t needed – it’s brought on by time.

So, you lose efficiency that way versus the thermostat telling the furnace whether we want it to run on first or second stage.

This is similar to when you’re installing a ceiling fan and the fan was made to have a dimmer switch for the light bulbs but you say, “No, I don’t want to go through the extra work for the dimmer switch and I’m just going to put in a regular light switch.”  So, now you’ve only got ON and OFF.

Well, you’ve got the potential to put the dimmer switch in and save electricity but you didn’t want to and now you only have full ON and OFF.

If you’re not sure if you have a two-stage furnace, or if you’re interested in having one installed with a WiFi thermostat system, call A.G. Roehrig today at 716-892-8857 to schedule an appointment.

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