For the last week or so my furnace (Lennox G61MPV-36B-070-12 ) would run intermittenly. Thermostat was set at 72, at times it would start to feel chilly and I noticed the temp in the house had dropped 4 or 5 degress, so I would cycle the thermostat on and off and then things would warm up again.
I checked for codes on the furnace and it was indicating “low sense current “ . I pulled the flame sensor (wow, tough spot to get at that ¼” screw) cleaned & replaced it and all seems fine now.

But since I was in there I decided to check things out and noticed the dip switches on the control board were set to operate with a two stage thermostat, trouble is my thermostat is single stage and there is no connection at W2 on the furnace.

So am I correct in assuming my furnace will always be at Low Fire when operating? Is there any negative consequences for operating like that? It is a small house and I have no concerns about the amount of heat so should I just leave it alone? Personally I can’t think of any downsides to just leaving it this way but maybe I am missing something? Just hoping to get some thoughts on this.

 

Welcome to the forum! Here is a link to the installation manual for your furnace:

http://www.lennox.com/pdfs/installat...g61mpv_iom.pdf

Starting on page 45 of the manual it explains how to configure the switches and the operation of the controls. Using a single-stage thermostat the control can be set to either a 10 or 15 minute delay before the second-stage heat kicks in.

 

If you have been comfortable in the past with the furnace configured for low fire only, I would leave things alone. You might not have enough duct capacity to handle the output of high fire.

 

Thanks firedawgsatx,

I have the manual and understand how to change the settings but was just hoping for opinions on whether or not I really need to change it or if there is any negative consequences that I haven't thought about. Seems to heat the house just fine the way it is.

 

If it is working properly and you are happy with it then no need to change anything.

 

Good point Grady, I certainly didn't think about that.

 

Thanks guys for the quick replies, I will just leave it as is.
@firedawgsatx: I see you are from San Antonio, visited there last winter, beautiful place!