Water heater mystery drain tube?

[ViewRVs]

I hooked my Argosy 20 motorhome up to water for the first time since the winter. I also flushed and drained my tanks (gray and black).

While running water with the hose connected to the house, I noticed water coming out of a drain tube beneath the water heater. It is not the drain tube. That is the other tube.

The red arrows point to the tube that is leaking. I am not sure what the valve is connected to the pipe in question. This a maze of pipes. I am thinking someone built a water heater bypass in all that mess.

I wonder if that is a pressure relief valve of some kind. Any thoughts?

[ROBERT CROSS]

Low point drain to remove water for winterizing.

Ours is in the street side rear storage compartment.

Bob

[SteveSueMac]

Low point drain for what exactly?

[Tom Nugler]

The arrow is pointing to what the manual refers to as a pressure relief valve for the water heater. Maybe over pressure for city water as well. The new water heater in the coach has a valve built in.
One of the previous owners capped off the end and laid a huge blob of solder over the flat end. I assume it was leaking.
No matter I removed it this winter along with a failed water pressure regulator.

Tom

[ViewRVs]

Steve,
I think it is to drain the water heater. My low point drain is likely my shore water connection behind my rear bumper.

It is a newer water heater and has the pressure relief valve on the outside.

[SteveSueMac]

I think I have one too (flying cloud) but thought the drain for the WH was the plug? I'm confused by it 😀 - will have to check the manual...

[Drewmcqu]

I believe the "pressure relief valve" is a safety device for this potential: pretend your 'it's-hot-enough-shut-off-the-heating-device-SENSOR-fails.' Then the gas or electric heating element would continue to run until something unplanned stopped it. When you heated this water into steam, the increadble pressure would rupture a waterline or explode your tank. This calamity would release dangerous steam and do much damage. The pressure replied valve is cheep (~$15) and should be replaced if leaking. DO NOT CAP/BLOCK IT OFF FOR YOUR SAFETY. It is plumbed to the outside in case it blows because of extreme pressure-so not to damage your cabin. Btw-there may be a small lever on top of the valve which may be opened and closed a few times an may stop leak (if God is smiling on you!).

[ViewRVs]

Any thoughts on where to find a pressure relief valve replacement? I'll have to take it out and bring it to my local plumbing supply shop.

[Tn Traveler]

Originally Posted by ROBERT CROSS

Low point drain to remove water for winterizing.

Ours is in the street side rear storage compartment.

Bob

I think this is correct. The water heater drains from the plug. There is a valve on the inlet side of the WH that lets the water into it. When winterizing, this valve should be turned off. The plug removed to drain the WH, and the water line low point valve opened to drain the water out of the lines. After all antifreeze is removed from the lines when de-winterizing close the low point valve, open the WH fill valve. Then fill the system with fresh water.

[ViewRVs]

Turns out, it was a pressure relief valve. It reads Webster No. 111. It is also stamped at "60" which is likely set for 60 PSI. That is actually a pretty nice feature I never knew I had! I do use a pressure regulator for the inbound hose. This is just another safe guard.

Now I need to search for a replacement and clean up some of that plumbing work!

[ViewRVs]

OK. I get the STUPID award for the day!

After tearing out the "bad" pressure relief valve and installing a new one AND a pressure gauge to monitor the pressure, I have determined that my original pressure relief value was working 100% properly! Duh.

It turns out I hooked up the RV to the house WITHOUT the pressure regulator and the house water pressure is at 70 PSI per the new gauge! The "bad" regulator was set at 60 PSI so it was doing it's job by purging water and pressure! Once I put in the RV water hose pressure regulator, it dropped to the 40-50 PSI range that the Camco regulator is set for!

And now I have increased my knowledge!