suburban water heater switch wires

[EgorKC]

We have a 2012 5th wheel with the 8 gal suburban gas/electric water heater. The switch went out bout 18 months ago and I had it replaced. Recently our water worked fine for a day and the next am lukewarm water. I tried the switch and it clearly felt stiff so I pulled it from the face. One of the 2 leads that go to the overload was cooked. The wire was still attached albeit frayed. I read another forum that an engineer felt the gauge of the wire for that unit was too small and it could overheat. I removed the overload cover and replaced the bad lead with the yellow flag connectors rated for 20 amp vs the blue ones rated for 15 amp using 12 ga, wire. I did not replace the 2nd lead as I doubt the switch would fit back into the space with 2 yellow connectors on it. I will test the overload with my ohmmeter and make sure it is not fried although it appeared good. Does anyone know if I can test the heating element as well without removing it? Threading wire and putting connectors on in that tight space was a test of patience. I have replaced the Heat element once before an I really do not want to again unless I have to.
Greg
P.S. We don't use it on gas as it is very loud and the recovery time is not as fast on this one as electric.

[EgorKC]

thanks everyone. I think I'll buy a replacement element as a spare and trust this was a bad crimp that took a few months to fail. It seems to be the consensus. Will find out on last fall trip of the year. Campground has hot showers if the need arises.
Greg

[BB_TX]

Your Suburban water heater most likely has a 1440 watt element meaning it pulls 12 amps. Even if it had a 1500 watt element it would only be 12.5 amps. And if someone happen to install a 2000 watt element it would be 16.7 amps.

The melted wires could have been caused by the switch overheating. But more commonly it is because of a poor wire connection; weak crimp, connector crimped on insulation, some wire strands missing from crimp, etc. Burned/melted insulation almost always occurs at a wire connection point. Poor connection equals resistance equals heat. And it doesn't take much resistance to generate enough heat to melt the wire insulation.

[2112]

A 1440W element should measure close to 10 ohms.

The switch is 233358, which is 16A.

[enblethen]

There can be two issues with element, open or grounded out! Open would not burn switch up, grounded would!

[bob213]

To check element I believe you can remove one wire from the element and then check across screws for continuity. Should be 13.2 or more.

[enblethen]

Some smaller gauge wire can handle the amperage, for example machine tool wire and some appliance wire. Yes, you can check continuty. I would be more concerned about it being grounded out. Turn off powwr, set meter to resistance. Measure from switch wire to neutral.

[EgorKC]

Nope. 16 amp 120V. It is the replacement switch part number from the Suburban website. That is why I suspected an overheat situation as the engineer I read on another site said the wire should as you suggest be able to handle 20 amp. The 16 ga. is not rated that high.
I just hope this didn't fry the heating element if the overload failed to trip. I was wondering if I can test the continuity on the element without removing it.
Greg

[enblethen]

Sounds like internal switch failure.
Look closely on sides of switch for voltage and amp rating. It should have been heavy enough to hold water heater. Somewhere arou nd 20 amp.

[EgorKC]

120V. It had the blue connectors with 16 ga. wire. The reason I suspect an overheat is that the wire was still connected , at least partially. The blue connector was entirely black and the back portion where the wire enters was melted away.

[enblethen]

8 Gallon? Should be either 6 or 10 gallon.
Yellow connectors are for 10-12 gauge wire
Blue is for 14-16 gauge wire.
Is this for 120 volt AC or for the 12 volt propane function?