Navien Condensate Drain Leak

[Rich F.]

Have a Navien NCB-210 that's been running well and Dana helped me tune last year.

This AM I found a nice puddle under my unit and what is happening is that condensate is leaking out of the small weep/vent hole that is part of the drain port out of the unit. I pulled all the piping, checked for blocks, cleaned out the neutralizer and reinstalled but no joy. Its still leaking. What appears to be happening is that a ring of water is forming right at the drain due to the surface tension properties of water and this is backing the water up and out of the weep hole. Its the craziest thing. Anyone ever encounter anything like this? I suppose it could be how I have the condensate drain and neutralizer plumbed but its been set up this way for a year now and today is the first day Ive had an issue.

Heres a video...any ideas?

 

[Rich F.]

Follow up.....

I removed the entire PVC drain system and replaced with the Navien supplied hose to connect the drain outlet to the neutralizer. Same issue. Water is literally getting "stuck" in a 1/2 inch pipe. I'm baffled.

 

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[Reach4]

Heres a video...any ideas?

How about sticking a soda straw up there part way, at least as a test. Maybe admit air. Maybe give something for the water to follow downward.

 

[Rich F.]

I think an air gap of some sort is in order.

 

[djdavenport]

Strange. Spent a few minutes looking at mine. Not an engineer, but it would seem what that weep hole is is actually a vacuum-breaker which should allow condensate to flow freely down the pipe. If it were clogged, it might explain what was happening and what your video showed. That section of the drain coming off the condensate trap retaining just enough suction to prevent it from flowing. But, it if were clogged, why would condensate be leaking out of it? Doesn't seem like you can have it both ways. Have you--just as a routine maintenance issue--cleaned and refilled the condensate trap itself? You might also want to CAREFULLY take some very fine wire or a toothpick and try and clean out the weep hole. I don't know if it's just an open port or if there some sort of valve or venturi involved. But, really, from your video, it looks like a vacuum-related issue. Be sure to report back after you've figured it out.

 

[Rich F.]

Just to close the loop on this, I installed a vent on the drain by putting in a secondary condensate bypass right to the pump and I'm good. No more leak. There was defintley some backpressure of some sort and the vent eliminated it. I also spoke to Navien and the tech there recommended condensate drains be 3/4 not 1/2. Mine is 1/2.

 

[djdavenport]

Thanks for the update.

 

[Bluemetal]

Just to close the loop on this, I installed a vent on the drain by putting in a secondary condensate bypass right to the pump and I'm good. No more leak. There was defintley some backpressure of some sort and the vent eliminated it. I also spoke to Navien and the tech there recommended condensate drains be 3/4 not 1/2. Mine is 1/2.

I have a 5 year old Navien CH240 and it started leaking condensate but from the gasket at the bottom of the heating chamber. It seems that the condensate gets stuck in the syphon and overflows. Would you be able to post a picture of the modification you've made to your Navien? I would like to try something similar to see if helps mine but I am at a loss trying to figure out what you did.

 

[chandra smith CCP]

Call a professional

 

[vic9909]

I have a 5 year old Navien CH240 and it started leaking condensate but from the gasket at the bottom of the heating chamber. It seems that the condensate gets stuck in the syphon and overflows. Would you be able to post a picture of the modification you've made to your Navien? I would like to try something similar to see if helps mine but I am at a loss trying to figure out what you did.

I have the same Navien Ch240 model. All you need is a new o-ring. $8 Home depot... 27.8mm or 28mm o ring. Put it on, it will be nice and tight. When you put it in, you won't be able to turn it. Fixes it quick.