Hi, I purchased a new high effiency Lennox G61V furnace a year ago,
And have had problems ever since. After numerous visits from the
Installer, we've finally determined that water from the cold header
Box (which sit directly behind the combustion inducer fan), does not
Drain out until the furnace shuts down. It almost seems like a suction or vacuum is stopping this water from draining out. So, basically if it is cold
Outside and the furnace runs for several hours straight, that water
Continues to build up and gets into the inducer fan, which causes all
Kinds of problems, and the furnace shuts down. Please note the condensate from the actual exhaust pipe appears to be draining fine.

The service people I've used have called lennox, but can not figure
Out why the water would not drain out until the furnace winds down or
Is shut off.
Has anyone run into a problem like this before?

Thanks,
Joe

Also, both the inlet and exhaust run to the outside on the side of the house and this gas furnace is in an upflow position.

This may seem too obvious, but is there a properly installed condensate trap on the drain in question? Pic is a little obscure... and, is the choke disc (if needed) present in the inducer inlet?

KC 13, I actually had the installer replace the condensate trap, and the problem still occurs (large amount of water drains out when furnace shuts down). Can you explain what the choke disc is, I didn't see anything about that in the lennox manual.

Thanks,
Joe

Some manufacturers will use different sizes of inducers for different sizes of furnaces. Those who don't will typically install a choke ring at the inducer inlet to limit the amount of draft to what the furnace requires. This allows them to use one inducer and apply it to any size unit they manufacture. If the choke is required but not present, the resulting "over-draft" can create excessive vacuum in the secondary collector. If the unit is a sealed combustion design, a partial restriction of the intake vent is possible. Check installation manual to assure combustion venting conforms to requirements.

Make sure your not trapping the condensation line twice. The furnace condensate colector trap is one if it ties in with another trap from the evaporator coil with out a vent tee that makes two and it will not drain.

Quote (So, basically if it is cold
Outside and the furnace runs for several hours straight,


This just doesn`t sound right,, a furnace that's doing its job shouldn`t run several hours straight without satisfying the thermostat,, unless its to small or the heat is going somewhere besides the living space, or bad installation

wmproop, the long run furnace time was when the weather here in Kansas dropped below zero for a few days. That temp along with my crappy old window generated longer run times.