Thread: condensate pump tubing

I remember when we used to put a condensate pump in we ran a 3/8 tubing up until it turn horizontal, then put a loop in it so that the entire line wouldn't dump right back into the pump and cause it to short cycle.
This one I saw today came out of the pump with 18" or so of 3/8 tubing, then was connected to 3/4 pvc that goes up a good 8' and turns.
I thought that was odd, but to make matters worse, about 15' down a nice level line it swings upward.
This means that about 20' or so of 3/4 pvc would be draining right back down because there's no way that little pump is pushing it out.

Do you guys agree?

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Yes, it might drain back if it gets air in the line or if it leaks by the pump. The pump should be rated in feet of head which should tell you if it can pump that high. The drain back during off cycle is another matter. Maybe a foot valve / check valve if the pump won't hold during off cycle. The loop won't help though, it will siphon everything in the line back anyway.
Any evidence of overflow?

Put those types of pumps back on the aquarium's where they belong.

Where is the receptacle outlet for that cord and plug? I see the cord disappear by the back corner of the AHU.

Originally Posted by Jerry Peck

Where is the receptacle outlet for that cord and plug? I see the cord disappear by the back corner of the AHU.

I'm thinkin' that the homeowner prolly hung that gypsum board, and then punched a hole in it so's he pull the power cord through and plug the condensate pump into the original receptacle.

Found these instructions, it appears a trap is recommended.

Kevin, did you notice the prhibition of any tubing larger than 3/8"? Also, there is an integral check valve.

Just a suggestion: when a link is posted to a portion of documentation, IMO it's helpful if there is also a link to the full documentation so readers don't have to go hunting for it if they want it.

http://www.zoeller.com/zcopump/zcopdfdocs/FM1605.pdf

FWIW, my take on those instructions:

Inspection Protocol

Condensate Pumps

Rev 1.00 June 29, 2007[1]

Observe Power Supply:
FYI: A separate, dedicated circuit is recommended, but not required
Power source should be constant, not via a device that runs intermittently.
Requires GFCI protection
Extension cord prohibited
Modification (“cut, splice or damage”) of power cord is prohibited
FYI: Pump can be wired to shut down the pump and the appliance if pump fails
FYI: Alarm can be wired into the Safety Switch and triggered if pump fails

Observe Location / Mounting /Age /Condition:
FYI: Capacity drops rapidly with head, by 2/3 between 3’ and 15’
FYI: For Zoeller, model number and date code are on the cord warning label.
Max tilt 1/8" for the length of the condensate pump
Pump should be below all evaporator drain and/or furnace drains serviced by p[ump
FYI: If mounted on bracket, recommended height is bottom of unit 6-1/2” above floor

Observe Plumbing:
Flexible tubing is max 3/8” ID
S/B is supported so as to prevent “Kink or Pinch Off” and block flow.
Pipe to pump should have 45 degree cut at end, tip in contacts with reservoir bottom
Drain lines s/b supported above the reservoir, no weight from line at reservoir
A hose clamp is recommended at junction with the barbed check valve
Maximum of 15 feet of vertical lift
Discharge pipe (from the check valve) should go to highest point possible (max 15')
High point of the discharge line higher than 5’ above floor recommended, but not required
Continuous downward slope of drain and discharge lines is recommended
If a continuous downward slope is not possible, form an inverted “U” at highest point
From high point, maintain a continuous downward slope.


[1] Based on instructions for Zoeller Model 520/521 http://www.zoeller.com/zcopump/zcopdfdocs/FM1605.pdf



Not clear to me: Can all or part of the line be rigid pipe?

"Just a suggestion:"

Obviously it would have been easier to copy and past the link. I copied the specific pages into PDF with the intention of adding to my report.
It wasn't until the next day I decided to post it here and didn't feel like searching for the site again.
But I'm glad you were able to find it.

"Can all or part of the line be rigid pipe?"

The problem in my pic is there is huge vertical rise with 3/4 pvc. I don't think it would make a big difference if the pipe is rigid or not, but it can't be larger than 3/8" at least until it turns.
You wouldn't think the pump is designed to push a 3/4" column of water 8'.

Now the reason I put loops in the 3/8 line years ago may very well have been due to a failed check valve. I actually hadn't given that much thought.
With the tube being clear, you could see water drain back when the pump cycled off causing it to start back. So, I put a loop in it and no it didn't siphon back ( that's field vs. theory).