HVAC condensate drain line is dry?

[arabianights]

greetings

I cleaned my residential hvac condensate drain line a couple weeks and blowed out the excess of water deposited in the U-shaped trap with compressed CO2. today when I checked the condensate line, I found the line is bone dry. temperature in my area has dropped and I usually have heat turned on when i'm home.

I'm concerned since usually the U-trap has water in it. is this normal?

 

[Averagesupernova]

Depends on several things. If you have not run the air conditioning for cooling the the evaporator will not condense water. If you are heating, you may not make any water either. What's the fuel source for heating? As far as I know only high efficiency gas furnaces with PVC pipe for exhaust make condensation.

 

[arabianights]

It's all electric, no gas!

I've not run house AC since before I cleaned the condensate line, then the weather has been cold and i only use heating. My condensate drain line was clogged a year ago during summer when AC was on and caused water overflow flooding the carpeted floor adjacent to HVAC/heater units space, so now i make a habit to check and clean the condensate line regularly. if i understand correctly, running heat doesn't produce water condensation hence no water accumulated in the drain line.

 

[Lnewqban]

I recommend keeping the trap full of water because a dry condensate pipe is a path to cold air to be sucked into the house due to the low pressure that is induced in the drain pan by the blower.

 

[Averagesupernova]

Depending on where the condensate drains, it might not matter if the trap is full. Often they drain into a floor drain. Sometimes they drain to the same place as the washing machine or a laundry sink. In this case there would likely be a condensate pump. If it drains directly into the sewer system you will definitely want water in the trap. It also depends on which side of the blower the air conditioner coil is. Sometimes they're on the suction side in which case they would draw air in from wherever they are placed. On the pressure side they will blow air out. If plumbed directly into the sewer system you'll lose a small amount of warm air into the sewer system if the trap is not full.