Suburban Thermostat Replacement - Stud Came Off Water Heater

[sportpilot76]

I have searched for a few days now about this happening to anyone and I can't seem to find where it has, so apparently I got the 1 Suburban heater with a defective thermostat stud.

Long story short, I went to remove the nut holding on the 12V thermostat and hi-limit switch and the nut came off with the stud and thermostat plate still attached. This wasn't a situation of the threads being galled or twisting it off, the weld below the stud failed. Just a poor weld from the factory and having never replaced the thermostat, it was enough to hold until now.

This unit is 10 years old so I can't complain, but surely there have been others who have had this problem.

My question is what did you do to repair?

The key to the thermostat working properly is being in close contact with the tank body so I can't weld it back on or use anything that will create an obstruction between the thermostat plate and the wall of the tank. I have considered just using JB weld on the thermostat plate - essentially 'gluing' it in place - not putting it under the thermostats, but around the edges to hold it in place. Sure this would work, but not optimal.

Any other ideas out there?

 

[danemayer]

Hi sportpilot76,

I don't recall anyone ever posting about the high-limit switch/thermostat coming apart like that. The high-limit switch doesn't typically need attention, so maybe that's why. But perhaps someone will chime in with an idea.

 

[JohnDar]

I don’t have a rig anymore, so I can’t test it. But if the face of the water heater will hold a magnet , you might get it to stay in place with some small neodymium magnets. Years ago, I had to replace that switch, but didn’t have any trouble with the threaded stud breaking off.


Sent from my iPhone using Tapatalk

 

[wdk450]

Do you think you could just adhere a new threaded stud to the water heater with JB Weld? Maybe use a flathead machine screw upside down for more screw to heater contact area.

I have used an epoxy brand called PC-7 that I found at an Ace Hardware store. They had a demo gimmick of a Coke bottle with all sorts and types of materials adhered to the Coke bottle with PC-7. It was something like this image, but with more nuts, bolts, plastic stuff adhered all over:

 

[sportpilot76]

Thanks for the replies.

I hadn't thought about using a magnet. I guess my head was just somewhere else because of the aluminum plate, but I think the magnet might actually work. Going to pick up a few and give it a go.

I also took a few photos to share.

 

[wdk450]

Have thought of a heat conductive epoxy under the whole thermo switch metal plate? https://www.google.com/search?q=hea.....69i57j0.13264j0j15&sourceid=chrome&ie=UTF-8

 

[danemayer]

From your pictures, I'm wondering if you have some tank leaks. Maybe time for a new water heater.

 

[wdk450]

From your pictures, I'm wondering if you have some tank leaks. Maybe time for a new water heater.

I know the thermostats have a protective cover, but isn't this where the overpressure valve likes to leak?

 

[danemayer]

I know the thermostats have a protective cover, but isn't this where the overpressure valve likes to leak?

I don't see the temp/pressure relief valve or the drain, or the secondary switch. And I think the high-limit switch is on the interior surface. So I think the picture is showing the interior.