Navien CH-240 siphon hose leak, gas smell

[Joe B]

Hi everyone,

Could a leaking siphon tube also result in gas escaping from a Navien CH-240 boiler?

I know - Naviens are fussy. But my CH-240 from back in 2010 has been humming along until just the other day. I found that it has begun leaking from the top of the "siphon hose" where it connects to the bottom of the burner.

I drained the condensate trap and refilled the siphon per the manual. But, it still leaks. I have a replacement part on order.

However, when running DHW with the case open to check the leak, I noticed a gas smell for the first time ever. Checked with my cheap gas detection tool and there is indeed gas in the garage where the unit resides. After airing out the garage, I ran it again with the case closed, and I did not smell gas, but my tool did detect a little by the unit.

Could the leaking siphon hose be the source of the gas? Or dare I begin to suspect a worse problem?

(Have any of you experienced this siphon hose tube leaking?)

 

[Joe B]

The aluminum output nozzle that the black siphon hose connects to has completely disintegrated. Perhaps this is why the model years that came after mine are now plastic on the bottom!

It's too bad, this Navien has been operating pretty well for 13 years.

Looks like I am getting a new combi-boiler (we have both radiant and DHW).

 

[Sponsor]

 

[Joe B]

Just fyi, my tech put in a temporary fix while we figure out a plan. He put in a little copper pipe stub, sealed it, and reattached a new replacement siphon hose that I had on hand. Just a short term fix to keep things operating.

 

[Fitter30]

Mix up some liquid dish detergent for bubbles and spray piping and gas valve to look for a leak.

 

[Jeff H Young]

dosent sound too bad I might tinker with the condensate and attempt to find /repair gas leak. but ignoring gas leak not so good idea , sevice life 13 years not bad but might be able to strech that out

 

[GReynolds929]

Yes it can cause gas to escape the burner when the unit is operating.