evaporator leaking water into duct

[frustrated_tech]

I have had many calls for water leaking from the ducts of a fir down evaporator, 1 1/2 ton r-22 units, apartments. I clean the coils, clean the squirrel cages, make sure the drip pan is draining and it still blows or leaks into the duct....without removing the entire evaporator is there a way to repair this problem or something else to check...I'm thinking by the time its gets this bad the coils probably need replacing? what do you guys think

[Jim Katen]

I have had many calls for water leaking from the ducts of a fir down evaporator, 1 1/2 ton r-22 units, apartments. I clean the coils, clean the squirrel cages, make sure the drip pan is draining and it still blows or leaks into the duct....without removing the entire evaporator is there a way to repair this problem or something else to check...I'm thinking by the time its gets this bad the coils probably need replacing? what do you guys think

At the risk of mentioning the obvious, did you check the blower speed?

Are these all Carriers by any chance?

- Jim Katen, Oregon

[Marc]

What is meant by 'fir down'? Downflow unit?

Marc

[Terence McCann]

Are you sure the evap coil is pitched correctly so that the condensate is actually heading for the drain? It needs to be pitched toward the drain outlet.

How much water have you poured into the drain to make sure there are no restrictions?

Is the evaporator drain trapped?

I've seen where moving to much air can lift condensate off the coil but that was on commercial equipment where you could change pulleys on the blower and the blower motor. Not sure you could replicate this problem on a residential unit though.

[frustrated_tech]

It's the original motor that came with the unit...I always use the same RPM motors that i take off...as far as pitch, these units, the coils are straight up and down...yes the drain is unclogged, i poured several glassed of water after i blew out the line...thanks for all the replies, give me more if you can think of anything...oh and these units are First Company, condensors are rheem, ruud, goodman, all different....

[Greg Booth]

Is the evaporator drain trapped?

You indicated that the drain was working when you poured water into it-but is it properly trapped? Without the trap, water can pond in the pan and lead to carry-off of moisture.

[Jim Katen]

It's the original motor that came with the unit...I always use the same RPM motors that i take off...

That's nice, but have you checked the speed settings? You can alter them at the motor's tap block or, sometimes, at a set of dip switches.

as far as pitch, these units, the coils are straight up and down...

He's not talking about the pitch of the coil front-to-back, he's talking about a slight pitch to one side. So that the drain side of the pan is lower than the non-drain side.

yes the drain is unclogged, i poured several glassed of water after i blew out the line...

If there's a running trap, it might work fine with a glass of water, but not work at all when the blower is running. The trap should be deep, like in the picture that they give you with the installation instructions. If these units are plumbed with running traps, that might be your whole problem right there.

- Jim Katen, Oregon

[Erby]

Traps like these are needed.

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