Need help replacing water heater outside switch

Boca_Shuffles

Well-known member
The outside switch on my water heater is not functional. The rocker switch does not rock. It is stuck in the on position, but may not be functional.

This is a Suburban SW12DE model.

What is the easiest (best) way to replace this switch?
1. Remove the whole heater.
2. Access from the back and depress the tabs that hold the switch in place.
3. Turn off all AC power, disconnect the battery, and then pry the switch out from the outside. Since I will be replacing the switch, it doesn't matter if the plastic switch is broken.
 

jbeletti

Well-known member
I'd go with 3, but use a tiny flat blade screwdriver and try to slip it in at the top of the switch and maybe depress the top tab, allowing you to rock the top of the switch forward, then brute-force it from there. Once out, tie the leads together with a wire nut and tape around that until you can add the replacement.
 

2psnapod2

Texas-South Chapter Leaders-Retired
Jim, you talk like you have done this before? Our water heater is not working on electric and I am thinking this might be the reason also. Have you had this happen before?
 

jbeletti

Well-known member
Michael - no, I have not changed this switch out before. I have blown the electric heating element in the past (twice in 8 years).
 

2psnapod2

Texas-South Chapter Leaders-Retired
Thanks Jim, I was hoping to get out to it this morning and do some troubleshooting since its been so hot, but its now raining. Electric and rain do not go well together. Oh well for now its working on LP and I will get to it soon. We only have 34 days left before our journey begins, so it will have to be sooner than later! And yes Go Wisconsin!!!
 

MC9

Well-known member
I've changed that switch a couple of times. The easiest way is just pry it out with a screwdriver. The replacement switch is fairly common. The RV repair guy was working across the street, he had a bunch of them.
 

2psnapod2

Texas-South Chapter Leaders-Retired
I did get out to check ours out. Had 120 Volts to the water heater. Checked the connection going to the junction box. Was that ever a daunting task. With all the spaghetti from the UDC! Is there a way to tell if the WH is getting 120 Volts from outside? I then checked Ohms across the electrode and it was something like 10. so I am assuming it is the electrode. Will have to see if Suburban will send me one since I am in Warranty. Do I need to drain the water to change it out? And what size socket is that?
 

JohnDar

Prolifically Gabby Member
My outside switch has been in the ON position since Day 1. Can't see any reason to change it, so "no touchee, no breakee." If I needed to service something electrical on the W/H, I'd be turning off more than just that little switch.
 

danemayer

Well-known member
I did get out to check ours out. Had 120 Volts to the water heater. Checked the connection going to the junction box. Was that ever a daunting task. With all the spaghetti from the UDC! Is there a way to tell if the WH is getting 120 Volts from outside? I then checked Ohms across the electrode and it was something like 10. so I am assuming it is the electrode. Will have to see if Suburban will send me one since I am in Warranty. Do I need to drain the water to change it out? And what size socket is that?

10 ohms across the electrode may not be a failure. See below.

General WH Diagnostic for No Hot Water
Note: Check System with Power on Unless Checking Individual Components
with an Ohmmeter
Check the circuit breaker to make sure it is not tripped. If tripped (possibly by low-voltage
condition or overloading), reset breaker and test.
Check for voltage at the on/off switch, and that the switch is functional. If voltage is
present at the input of the switch but not at the output when turned on, replace the switch.
An alternative test is to shut off power to the system, disconnect wires to the switch and
check with an ohmmeter. With the switch on, lack of continuity indicates a bad switch; continuity
indicates a properly working switch.

Check for voltage input to the thermostat/E.C.O. switch assembly. Verify voltage is at
all terminals. Check to make sure that the E.C.O. has not tripped, in which case the button
can be pushed to reset it. However, if this condition has occurred, the thermostat must be
tested to make sure it has not failed and the water heater is now cycling on the E.C.O.
switch. If voltage stops at any terminal and the water is not hot, replace the assembly.

An alternative test is to shut off power to water heater and disconnect wires to the thermostat/
E.C.O. assembly. Test for continuity from the input terminal to each of the other terminals.

An open indicates which component is bad. If there is continuity, and the thermostat is not
satisfied the component is in proper working order.

Check for voltage at the heating element. If voltage is present at the heating element,
but there is no amp draw on the heating element, replace the heating element.

The heating element can also be checked with an ohmmeter with the wires disconnected. A resistance
reading that can be computed using Ohms and Watts law will determine proper resistance.
The heating element should read approximately 14 - 17 Ohms
(remember that the voltage
and wattage are printed on the heating element case). No resistance indicates an open element,
while continuity with no resistance indicates a shorted element which would also be
indicated by constant tripping of the circuit breaker.
 

2psnapod2

Texas-South Chapter Leaders-Retired
Thanks Dan, I will also be checking the Thermostat soon. Not sure what is going on here. Went to the Suburban website to see about a dealer to repair and the closest one is like 100 miles away. Sounds strange since there are RV Repair shops close by.
 

2psnapod2

Texas-South Chapter Leaders-Retired
Ok everyone, I am still trying to see what is wrong with this water heater. I have verified that I have power going to the water heater. I have pushed the reset button, and have removed the covers to both the element and the thermostats. I do have some power at the stat but not at the element. How do I tell if it is going thru the stat? I have attached a Diagram as to the switch. Can you tell me where I should have 110 Volts?

Water Heater.jpg
 

danemayer

Well-known member
Michael, here's the more complete diagram: If you have the common lead of your volt meter on a good ground, and you've got 110V on both sides of the switch, and on one side of the ECO/Thermostat assembly, but not on the other side, the ECO Thermostat assembly is open. If you've already tried resetting it, and the water is not hot, it sounds like you'll need to replace the assembly.

ECO (energy cut off) Thermostat is also known as the High Limit/Thermostat assembly.

WaterHeaterElectricWiring.jpg

"Check for voltage input to the thermostat/E.C.O. switch assembly. Verify voltage is at
all terminals. Check to make sure that the E.C.O. has not tripped, in which case the button
can be pushed to reset it. However, if this condition has occurred, the thermostat must be
tested to make sure it has not failed and the water heater is now cycling on the E.C.O.
switch. If voltage stops at any terminal and the water is not hot, replace the assembly."
 

2psnapod2

Texas-South Chapter Leaders-Retired
Thanks again Dan, it does sound like I need another ECO/ Tsat Assembly. I will have to contact Suburban on Monday. Thank goodness it is only on electric and we have hot water with gas. I sure appreciate your help. I must have missed the electrical schematic class some where.
 

Boca_Shuffles

Well-known member
Jim B your suggestion was right on.

I used a small screw driver to pop the switch out. The wires in the back only came out about 1/2 ". I used two forceps to hold the wires while I changed switches. I applied dielectric grease to the contacts and popped the new switch in. Total time was about ten minutes.

This is a picture of the new replacement switch. As Jim mentioned, it is only held in by the two little tabs at the top and bottom.

Water Heater Switch.JPG
 
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