Suburban SW6DE Water Heater 120VAC Side

[j-d]

This quit heating on electric on a trip a couple months ago. I thought we might have run it with the tank not full and burned the element out. I removed the element cover and wiring, showed OPEN. So I ordered a new element and set about installing it today. A thin wall socket would be better than the 50-year-or-more-old 3/4" drive, 1-1/2" socket I had on hand, but the element came out easily. Calcified but not visibly damaged. Flushed tank, installed new element, installed anode, filled tank and turned on.

NO HEAT!!! Element tests with resistance. OEM is 10-ohm for 1440-watt. I bought a lower wattage element to help with power consumption, 1000-watt and it tests 15-ohm.

The circuit is:

15A Dedicated Breaker, then Residential Wall Switch with Indicator Light - From there it's the wiring shown in the Suburban Manual on Chris Bryant's site

Small Rocker Switch on Water Heater itself
Thermostat and ECO with Black Wiring, left side of the two assemblies
The Element (all wiring so far is Black/Hot
White Neutral from Element back into Coach Wiring

Every bit of this shows HOT with my non-contact pocket tester
Shows 120VAC with a meter wherever I can access
Shows continuity on Ohm Scale. Switch on Heater, all Thermostats, and Element shows 15 ohms
Power ON and both sides of the Element (black and white wires) show HOT

All this and Zero Amp Draw on my clamp-on AC Ammeter. Left system ON thinking meter might have failed, but NO Hot Water after an Hour

What am I missing here? Seems like I have Volts that can't deliver Amps to produce Watts and get me some hot water.

Now I wonder if I was freaked out from the get-go: The element I took OUT shows, today, 10 ohms, the factory spec!

[j-d]

FIXED!!!

Chris and BB, you nailed it. And shame on me, I usually read all the tech stuff.

Pulled breaker box cover, every Hot and Neutral was tight, but I tweaked them all

Pulled Water Heater Switch from Control Panel - It's a residential switch and again every SCREW terminal was tight

Looked in under-sink cabinet where he water heater is. No less than FOUR junction boxes under there! Fortunately for me, the inaccessible junction box on the water heater itself was wired to the most easily accessible box in the cabinet, screwed to the floor. Unfortunately for me, it was one of those sorry Mobile Home/RV punch down boxes. Soon's I had it open I could see the White Neutral was Loose and Scorched. There was enough cable for me to trim, strip, twist together with pliers, the Hot, Neutral and Ground. Then Wire Nuts. Gutted the punch down box, cut the inner plastic structure out, and reinstalled as a Splice Box. DONE!

I don't regret the time I spent on this. Never a good time to spend a day on a simple project, but still: I've been able to deep clean the water heater, reduce its wattage demand from 12A to 8A, prevent future problems with the junction box, and...

...improve troubleshooting skills...

Thanks, Guys!

[j-d]

BB_TX wrote:
..loose neutral wire in the junction box on the back of the water heater...

Squares with Chris' diagnosis, too. I made a test cable from an old heater cord:

OEM 1440W element, heating at 11.8 Amps

NEW 1000W element, heating at 7.8 Amps

Tomorrow is another day, will be getting into those connection areas. Oh, well, once I get it running again, I think I'll like having knocked 4 amps off my water heater draw. Will help on those 30 amp power poles!

Thanks, Friends! I'll report back.

[BB_TX]

There was someone recently posted about going thru the same thing with similar symptoms, HOT as far as he could trace. In his case, it was a loose neutral wire in the junction box on the back of the water heater.

[j-d]

That WHITE wire... About the only suspect I could come up with too.

Now for the worst part: Unpacking under the Kitchen Sink to see if the connection got broken there...

[Chris_Bryant]

If you read line voltage on both sides of the element, you have an open neutral- check it back to the box.