Capped terminal line by water heater

[Tjbland]

Hi folks!

Does anyone know what that black plastic nut is circled on the photo? It is located inside my water heater compartment, and is plumbed in right near the WH bypass. I've had some issues with water slowly leaking out of there, something that I can stop by re-tightening the nut by hand. Is there any way to prevent this from continuing to happen? It's just such a pain to reach in there and tighten. We've got a 2012 Stealth Evo.

Thanks!

[Flybob]

Possible a winterizing port. Was there a previous owner? I do not recall seeing that configuration before so possible owner installation.

[dbledan]

You could always screw on a shutoff valve.

Cheaper would be to add Teflon tape or swap the washer under the cap depending on how it looks when you remove it.

[Tjbland]

Thanks for the responses! I think I'll try getting a new cap or washer and using some thread dope. It proved pretty impossible to teflon tape it given the space limitations.

[nomad297]

Originally Posted by Tjbland

Thanks for the responses! I think I'll try getting a new cap or washer and using some thread dope. It proved pretty impossible to teflon tape it given the space limitations.

If you’re going to dope the threads, be careful selecting which dope you use. There’s not many pipe dopes that work well with plastics — especially any black plastics. The wrong dope will solve your problem at first, but it will definitely degrade the plastic pretty quickly and cause a bigger mess than what you started out with.

Bruce

[formerFR]

https://www.youtube.com/watch?v=pHK5k1P0DZM

probably a winterizing 'blow out' valve to connect your air hose to...

but, without seeing what's under that cap, it might be hard to ascertain...

[Larry-NC]

Originally Posted by Tjbland

Thanks for the responses! I think I'll try getting a new cap or washer and using some thread dope. It proved pretty impossible to teflon tape it given the space limitations.

It looks like you could simply remove the cap, insert a garden hose washer into the cap, and put the cap back in place. You would have to try it to see if it fits.