northeastguy78
New Member
Hi folks,
I have a dilemma here and wonder any experts out here can shed some lights. I have a 2003 Lennox Furnace (model 48C-115-3), it's a 4 ton unit that sizes roughly 2100 sq.ft. single zone. I have a 2 story home with a basement. The furnace is located in the basement (finished) and seems to heat the house fairly well.
I noticed the fan speed board had the cool set to high (black wire) (this is normal as I know cooling needs to have fan speed set to high). However, on the board where it said "heat" it has the fan speed low (red) plugged into it. My furnace fan has 4 speed (goes from black, brown, yellow, red) black being highest speed and red being lowest.) So basically red wire is plugged to heating and brown, yellow are on park 1 and park 2.
I have always read the fan speed should be on low for heating and high for cooling. However, I open the Lennox manual and noticed it had a chart diagram for fan speed and read....for my unit model (48C-115-3) showed black wire (High) for cooling and brown wire (med-high) for heating. Now, the unit currently has RED (low) plugged onto heating... which shows the lowest speed. Should I leave it alone or switch it to factory recommendation at med-high?
I heard one thing but read another. Basically I want to find out if I could possibly damage anything by changing it to med-high. I also don't want the pressure to be too high since factory recommended med-high when it is currently set at low.
If I switch it to brown (med-high) or even say yelow (med-low), it would force more air into the upper floor but cooler heated air since the fan speed spins faster. Will that make the furnace cycle faster since it is pushing harder. When it is pushed harder, it will reach the desire temperture faster, but the objects may not necessary be warm fast enough, hence drop in temp faster and furnace cycles quicker.
I guess my main question is, what should I do? leave it on red (low) but the manual says it needs med-high (brown wire)
Please help.
thanks,
I have a dilemma here and wonder any experts out here can shed some lights. I have a 2003 Lennox Furnace (model 48C-115-3), it's a 4 ton unit that sizes roughly 2100 sq.ft. single zone. I have a 2 story home with a basement. The furnace is located in the basement (finished) and seems to heat the house fairly well.
I noticed the fan speed board had the cool set to high (black wire) (this is normal as I know cooling needs to have fan speed set to high). However, on the board where it said "heat" it has the fan speed low (red) plugged into it. My furnace fan has 4 speed (goes from black, brown, yellow, red) black being highest speed and red being lowest.) So basically red wire is plugged to heating and brown, yellow are on park 1 and park 2.
I have always read the fan speed should be on low for heating and high for cooling. However, I open the Lennox manual and noticed it had a chart diagram for fan speed and read....for my unit model (48C-115-3) showed black wire (High) for cooling and brown wire (med-high) for heating. Now, the unit currently has RED (low) plugged onto heating... which shows the lowest speed. Should I leave it alone or switch it to factory recommendation at med-high?
I heard one thing but read another. Basically I want to find out if I could possibly damage anything by changing it to med-high. I also don't want the pressure to be too high since factory recommended med-high when it is currently set at low.
If I switch it to brown (med-high) or even say yelow (med-low), it would force more air into the upper floor but cooler heated air since the fan speed spins faster. Will that make the furnace cycle faster since it is pushing harder. When it is pushed harder, it will reach the desire temperture faster, but the objects may not necessary be warm fast enough, hence drop in temp faster and furnace cycles quicker.
I guess my main question is, what should I do? leave it on red (low) but the manual says it needs med-high (brown wire)
Please help.
thanks,
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