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03-17-2009, 03:05 PM #1Regular Guest
- Join Date
- Mar 2006
How to tell if two stage heating is two stage?
This is going to sound pretty stupid, but I can't tell if there really are two stages of heat coming from my unit. I have the Lennox G61MPV, and have checked the dip switches and jumpers and all looks correct for 2 stage operation. However, it seems like whenever heat is on, it is on full. Should I be able to tell a noticable difference from first stage heating vs second stage heating, either in blower speed or air temp exiting the vents?
Sorry for such a basic question, but it really has me questioning if I'm getting the benefits of a dual stage heating unit.
03-17-2009, 03:13 PM #2
Hire a professional, it involves gas pressure readings and low voltage control meter readings.
03-17-2009, 03:34 PM #3Professional Member
- Join Date
- Jan 2007
- N.E. Ok.
Being a 2 stage homeowner in my spare time, i can tell increas in airflow in 2nd. stage
03-17-2009, 03:38 PM #4Regular Guest
- Join Date
- Nov 2008
"A two-stage furnace requires all or some of the following components: a two-stage gas valve, two-stage controls, a
multiple speed blower motor, and two-speed inducer motor.
A two-stage control is any control
that uses a two-stage adjustment of the furnace input rate in response to changes in the heating
load. Based on thermostat demand, the two-stage control cycles the burners between a reduced
heat input rate and off or between the maximum heat input rate and off. "
I guess if you ask for 1F or 10F above the current ambient you'll the low or high rate.
03-17-2009, 03:59 PM #5
It can be hard to determine if a furnace is in first or second stage.
You may want to try this.
Turn your heat up one degree above room temp.
Then go to the furnace, and have your wife turn the stat up another 5 or 6 degrees.
And see if you hear a change in its operating noise.
Its possible your contractor wired it wrong.
And you'll just need them to come out and correct the wiring.Contractor locator map
How many times must one fix something before it is fixed?
03-17-2009, 04:48 PM #6
03-17-2009, 05:01 PM #7
You should notice a change in blower speed and the speed of the inducer fan as well as "louder" flame as it increases in intensity.... if it's audible. Some cabinets are pretty quiet. You might also hear the gas valve open to the higher setting.
The bad news, is that you might have to sit there a while.
On my unit, it goes from somewhere around 750CFM to 900CFM, so to me it's a pretty noticeable increase in airflow comming form the vents. Although... my humidifier bypass pipe has a damper on it so it also can increase or decrease the air flow by almost 150 CFM.