water heater plumbing

[johnnyboy]

I have a NTM '03 18DT hybrid. The line to the water heater has a small leak at the shut off valve. I can't find a piece that matches.

There is a line that T's off the hot water back into the cold line (see picture). I assume that is for anti-freeze. I full time and won't be doing that. Can I simply get a turn off switch and re-do the hot and cold lines so that they run straight in and out? Or does someone know where to get that turn-off piece?

[javelin]

Hi, no responses to you yet, so to get the ball rolling:

Looks like a 3 way hot water tank winterizing bypass valve to me. When in bypass mode the flow is from the cold pex line (bottom right of your picture) up through the valve to the red pex hot line (the blue pex line into the water heater is blocked). The hot water tank typically would have a one way check valve built into its hot outlet (prevents any back flow into the hot tank)......so the pink antifreeze would flow from blue pex (bottom right) to red pex (top right) and nothing into the hot water tank. Flip the valve and you would have normal flow through the hot water tank with the bypass leg now blocked by the valve.


You could forget the bypass altogether and reconstruct your pex lines into a simple cold in, hot out system, but there are advantages to having the bypass even if you don’t think you will ever need to Winterize. For example: resale value; also if you ever have a problem with leaks in your hot water tank the bypass can allow you to still use your coach water system without putting more water into the tank leak area (no hot water though); same if you ever need to change out the hot water tank (but a temporary cap would likely need to be used where the hot outlet check valve is now; some people use the bypass valve to fine tune the hot water temperature to their coach.....open bypass a little and it adds some cold to the hot.


Is the valve leaking internally or externally? Are you certain its the valve that is leaking or a pex fitting? Do you have three male threaded ends on the valve or two male and one female? You might be able to find a brass 3 way valve to replace what you have, or it might be easier just to use a new 3 way valve with push on pex fittings and modify the existing pex piping for best re-assembly and fit. Good luck.

[johnnyboy]

Originally Posted by javelin

Is the valve leaking internally or externally? Are you certain its the valve that is leaking or a pex fitting? Do you have three male threaded ends on the valve or two male and one female? You might be able to find a brass 3 way valve to replace what you have, or it might be easier just to use a new 3 way valve with push on pex fittings and modify the existing pex piping for best re-assembly and fit. Good luck.

Oh, it's def the valve. Water drips out when closed and shoots out when open. I put some WaterWeld on it to stop the drip, so am not using the hot water heater for now.

There are 3 male threaded ends. Couldn't find anything to match it anywhere, retail or online. At Home Depot, the employee suggested a T with 3 water hose adapters. But when I got home, I realized the Pex lines had some sort of compression adapter on them, so they wouldn't screw on to the adapters.

I'll b needing hot water soon, so will look into your suggestion re: a 3 way fitting. Otherwise, I'll just reroute the lines with a turn-off valve.