Condensate pump

northernsoul

Hi there 

we have a 10 year old Lennox SLP98 furnace that was flashing a e 225 (high pressure switch) error on startup this morning on call for heat.  It seemed to clear itself and has been running fine since.  I’ve read that that error can be due to lots of reasons including condensation.

This furnace also has a condensate pump to a sink drain as there is no floor drain.

We’ve only been in house for 6 months so not sure of it’s functioning.

the tube from the pump up to joists over to sink has water in it.  Is that normal or shoud the vertical tube out always be totally clear?

ive never actually seen/heard it run yet.

northernsoul

Do these run a lot with a furnace? Or more with AC running?

Big Ed_4

Yes there is a check valve on the outlet side of the pump to prevent the discharge condensate from draining back .

High pressure error , make sure the condensate drain from the boiler is clear as well as the trap .. Check the end of the drain where it enters the pump . Make sure it does not go to the bottom of the pump . Give it a air gap ..

northernsoul

Big Ed_4 said:

Yes there is a check valve on the outlet side of the pump to prevent the discharge condensate from draining back . High pressure error , make sure the condensate drain from the boiler is clear as well as the trap .. Check the end of the drain where it enters the pump . Make sure it does not go to the bottom of the pump . Give it a air gap ..

thanks! When furnace is running how often should these pumps need to run? Daily?

JUGHNE

They run when the float inside starts the pump.
You can test it's performance by pouring water into it.
It usually has a equipment shut down float also which will shut down the equipment if the pump over fills for any reason. You may see 2 small wires coming out of the pump, maybe not hooked to anything, don't worry about that.

The main thing is that the furnace drain hoses are clear to pass their water.
All of the drains on a furnace have some method of trapping that sometimes plugs and needs cleaning.
This could be your flashing light issue.

These condensing furnaces could put out a few gallons of water per day.

EBEBRATT-Ed

A condensing furnace will produce 1 gallon of water per 100,000 btus of gas burned/hour.

So if you had a 75,000 btu furnace that ran for 20 min you would get about a quart of water. Time to check the drain tubing and condensate pump and make sure they are clean and working

JUGHNE

IF the 2 little wires are NOT hooked up to the furnace control, (again don't worry about that), then the furnace does not rely upon the pump operation. The water will still drain out onto the floor or into a bucket if pump fails.

Just do not let the furnace drain hose be under water in the pump or this constitutes double trapping and may not drain correctly. (As Big Ed said above).

The water is acidic and will eventually ruin paint, copper, brass, concrete and cast iron.

northernsoul

Seems to be wired right into furnace

northernsoul

Looks like the drain exits from plenum where AC is?

pecmsg

in my location that pump Must be plugged in not run into the cabinet. 

I would get a back up pump for when it fails. 

northernsoul

I put a pan in the sink where the condensate pump empties and sure enough there is water (about a cup so far) being pumped out so good news that hopefully no clogs.

JUGHNE

The flex hose is connected to the AC condensate drain pan, it will be producing water when cooling.
The furnace drain is that hard white PVC pipe.
There looks to be a trap on the outside and also be a drain line out thru the furnace where that black trap device is.
Possibly 2 or more hoses inside that could need cleaning.