Hot water leak

[heritage2006]

It seems that every time I turn on the hot water it leaks from under the sink. First time I saw it the water had run across the floor (behind the cabinets) and then out onto the floor.

I located the source of the leak and tightened it. That lasted for awhile and now it continues to leak - BUT not always. Sometime it does - sometimes it doesn't ??

The first pic I attached circles the two areas where I see dripping coming from. And the stain on that black thing - which was there the first time I noticed it - telling me it has leaked in the past.

The second and third pic are just close-ups of the areas.

Other than tightening the areas some more, any other solutions ? I keep the door open when the hot water is on so I can keep an eye on it and I also keep a cloth there now. I'd sure like a permanent solution ??

While I'm on the subject of the Hot Water, another thing that happens is that there is dripping from the outside vent (4th Pic) and the water is staining the RV (5th Pic). This also happened in my previous coach but should this be happening ??

[Shadowcatche]

One way to absolutely find out exactly what is leaking is to first dry the area then spray it with talcum powder then apply water pressure. Any wetness will become apparent. A bit of red food coloring in the water in high concentration can help the process.
The other idea is to empty the tank and use air pressure and spray a soapy liquid to the area, it will bubble at the leak, this requires a compressor and the fitting you use to blow out the water in the system to winterize.

[heritage2006]

I'm pretty sure I know where it is leaking from but thanks for your input.

Hoping to get some suggestions on how to stop it ?

[clubmed98]

have you checked the zinc...you check it from front by removing cover and you will see the plug at bottom of water heater..however not all heaters have the zinc but my old 98 DSDP did so assuming newmar didn't change thats a good place to start...have to depressurize water line and shut off pump and disconnect outside water supply..this is because when you remove the plug the tank drains..when zinc is gone you get corrosion that could cause leaking issues...2nd idea re outside water is a leaking pressure relief valve...shuting off and on may re seat..note once again release pressure or stand back...I have no idea re back end connection leaking..

["007"]

I would disconnect all pipe attachments to the tank inside under sink area.
You may have a cross thread fitting.
If not than I would use some plumbers tape around thread fitting or liquid plumber goop and reattach the plumbing fittings.
The relief valve outside may have to be back flushed to remove dirt particles from inside fitting.
When you fill the tank do not operated the relief valve or you will lose the air that should be trapped at top of water tank to allow heated water expansion in tank.
Relooking at your side wall outside water marks you may have a slot in your awning rail that was not caulked in rail and the water is dropping down the side wall.

[heritage2006]

Thanks for all your input. Based on your comments, I think this is a job for the 'professionals'. So the next time I get the rig serviced I will have them have a look at it.

In the meantime, I do know where the water (a slow drip) is coming from and will keep an eye on it at all times. I also have a cloth there to catch the water.

Of course, ever since I posted this originally - it hasn't dripped since !! Murphy's Law !! LOL

I'm in a cold climate right now, and in a very small Town so any service related items would be horrifically expensive. I will have it looked at when I head South of the Border.