12 inch slurry pump engine

Condensate pump

Condensate Pump Issue

A 10-year-old Lennox SLP98 furnace was flashing an e225 (high pressure switch) error on startup. The furnace has a condensate pump to a sink drain. The tube from the pump up to joists over to sink has water in it. It was asked if that is normal or should the vertical tube out always be totally clear.

Troubleshooting and Advice

A check valve on the outlet side of the pump prevents the discharge condensate from draining back. High pressure error can be due to a blocked condensate drain from the boiler. Check the end of the drain where it enters the pump, ensuring an air gap. Make sure the condensate drain from the boiler is clear as well as the trap.

Pump Operation and Maintenance

Condensate pumps run when the float inside starts the pump. You can test its performance by pouring water into it. They usually have equipment shut down float also which will shut down the equipment if the pump over fills for any reason. 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. These condensing furnaces could put out a few gallons of water per day.

A condensing furnace will produce 1 gallon of water per 100,000 BTUs of gas burned per hour. Check the drain tubing and condensate pump and make sure they are clean and working. Do not let the furnace drain hose be under water in the pump. The water is acidic and will eventually ruin paint, copper, brass, concrete and cast iron.

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.