Water Heater Troubleshooting

[sclifrickson]

Looking for some help in troubleshooting our 2-way water heater. The electric heat has stopped working. Things I've tried so far: turn switch on water heater itself off then back on; pushed on dual reset buttons on water heater (no perceptible movement, so I don't think they were tripped); turned breaker all the way off then back on; and I even went so far as to turn it all off then drain and flush the tank. No change after any of this when operating under shore power. Propane heat works fine. Ideas?

[escape artist]

Originally Posted by sclifrickson

Looking for some help in troubleshooting our 2-way water heater. The electric heat has stopped working. Things I've tried so far: turn switch on water heater itself off then back on; pushed on dual reset buttons on water heater (no perceptible movement, so I don't think they were tripped); turned breaker all the way off then back on; and I even went so far as to turn it all off then drain and flush the tank. No change after any of this when operating under shore power. Propane heat works fine. Ideas?

Hi: sclifrickson... Bin there done that. A new electric element fixed it!!! Cost under 20 bucks and when all's said n done the RVTech said they're supposed to be all in one piece... not two like ours was. Alf
escape artist N.S. of Lake Erie

[PGDriver]

Scott have you checked for current at the element connection.


Cheers
Doug

[Loren & Cathy]

When I read this, the first thought that came to my mind is that the element failed. Loren

[cpaharley2008]

Another reason why I have no desire to the dual power set up, too easy to mess up. I can see the benefits for those hooked up all the time and not moved, but each time there is a disconnection there exists the possibility of error.

[padlin]

From the water heater manual.

a) Check the circuit breaker in the coach to make sure it has not tripped.
b) Check for 120-volt AC to the ONIOFF switch (lower left hand corner of the control pan) on
gadelectric water heater. If voltage is present on one side of the switch and the heater still doesn't
work, replace switch.
c) Press the reset button on the heater. Located in the control pan.
d) If, after pressing the reset button and turning the power back on, the heater still fails to operate,
turn off the power and check all wire connections.
e) After the first four steps have been followed, the heating element should be checked for
continuity with a voltmeter or other testing device. If defective, replace the element.

http://www.waterheatertimer.org/pdf/...ice_Manual.pdf

[alanmalk]

Originally Posted by padlin

From the water heater manual.
...
e) After the first four steps have been followed, the heating element should be checked for
continuity with a voltmeter or other testing device. If defective, replace the element.
...

From the manual - essentially the "e"step. (I added my own personal comments in red).

My "do it quickly comment" is only necessary if the heater has no water in it.

My "disconnect one wire" comment is intended to prevent any other appliance on the water heater circuit from giving a false reading.

And make 110% certain that you have disconnected the trailer from all 115 Volt power before you try taking off a wire from the element, prior to measuring the resistance of the element. This is easy to forget because the first step requires that the power be on. Take your tool kit with the screwdrivers and put it near the trailer power plug so you have to walk over before you can unscrew wires.

--
Alan

[steve dunham]

Originally Posted by PGDriver

Scott have you checked for current at the element connection.

If you remove the propane burner tube you can access the black plastic piece that covers the terminals of the electric heating element . The terminal cover is held on by 3 screws .

With a volt meter and the circuit energized check the voltage across the terminal screws of the element
If you read 120 VAC then the element is probably bad
If you read 0 VAC then the thermostat is bad or satisfied, or the high limit is bad or tripped or the unit switch is off or bad or the circuit breaker is off or bad or the interior switch is off or bad or there is a bad splice in the circuit.
If the element is good you should read 10 to 12 ohms resistance
If the element is bad you should read a high resistance or infinity.
( Do the ohms test with the power off or you may burn up your meter)

If the element is bad you will have voltage present but NO current flow . Current will not flow across an open circuit.

It is often easier to troubleshoot a circuit when energized than when it is deenergized. If a switch is good ,turned on and energized then you should read 0 volts across the switch . If the switch is bad or off , you should read 120 VAC across the switch.

ALWAYS ASSUME A CIRCUIT IS ENERGIZED AND ACT ACCORDINGLY !!

[alanmalk]

Originally Posted by steve dunham

If you read 120 VAC then the element is probably bad

Steve, I would take (a modest) exception to that statement.
Rather, I would say the voltage across a good working element should be near to 120 VAC. Or to be precise, as close to the voltage coming into the trailer, minus any voltage drop in the circuit. And in a proper circuit that you find in an Escape trailer, this voltage drop should be minimal. My point is that the voltage reading at the element terminals really only tells you that power is present. It may be going through the element, or it may not. The Resistance test, with the element out of the circuit (minimum of one wire disconnected) is a much more positive test regarding the state of the element - short of having hot water.

I am also tempted to say that "all" electrical appliances should have the intended voltage at the plug or terminals when operating - or they will suffer from low voltage operations. An air conditioner should have near to full voltage at the terminals or it will shut down if so protected.

All that said, your statement is still reasonable if you say "probably bad, if you aren't getting hot water after a few minutes".

And this is worth repeating!

Originally Posted by steve dunham

ALWAYS ASSUME A CIRCUIT IS ENERGIZED AND ACT ACCORDINGLY !!

--
Alan

[steve dunham]

Originally Posted by alanmalk

Steve, I would take (a modest) exception to that statement.
Rather, I would say the voltage across a good working element should be near to 120 VAC. Or to be precise, as close to the voltage coming into the trailer, minus any voltage drop in the circuit. And in a proper circuit that you find in an Escape trailer, this voltage drop should be minimal. My point is that the voltage reading at the element terminals really only tells you that power is present. It may be going through the element, or it may not. The Resistance test, with the element out of the circuit (minimum of one wire disconnected) is a much more positive test regarding the state of the element - short of having hot water.

I am also tempted to say that "all" electrical appliances should have the intended voltage at the plug or terminals when operating - or they will suffer from low voltage operations. An air conditioner should have near to full voltage at the terminals or it will shut down if so protected.

All that said, your statement is still reasonable if you say "probably bad, if you aren't getting hot water after a few minutes".

And this is worth repeating!


--
Alan

When I started my electrical apprenticeship the NEC used
110 /220 VAC as the nominal voltage , then it was changed to
115/230 VAC now it's 120/240 VAC
First it was 440 VAC then it changed to 460 VAC and now it's
480 VAC.
They are all nominal voltages .
It is not uncommon to see circuit voltages vary from 114 to 125 VAC or 455 to 490 VAC .They are all referred to as 120 VAC or 480 VAC.
So when I said 120 VAC that does not mean the voltage is exactly 120 VAC . We use the voltage levels stated in the code.
IE: 116 or 117 or 118 or 119 or 120 or 121 or 122 or 123 VAC are all referred to as 120 VAC.
Just like the battery in your trailer is referred to as a 12 VDC battery even though the battery may read 13.0 VDC.

[sclifrickson]

Originally Posted by PGDriver

Scott have you checked for current at the element connection.


Cheers
Doug

I have not done so. I have a multimeter but I am only knowledgeable enough to be dangerous with it. There are four leads I see via the exterior access hatch. Any idea which would be the right ones to check for current? Do I need to worry about damaging anything if I put probes on the wrong ones?

[sclifrickson]

Aha! Thanks, all! Sorry I didn't read all the responses before my last post. Ok, I will pull tools out and dig in. I'll post back after. Cheers, Scott

[alanmalk]

Originally Posted by sclifrickson

I have not done so. I have a multimeter but I am only knowledgeable enough to be dangerous with it. There are four leads I see via the exterior access hatch. Any idea which would be the right ones to check for current? Do I need to worry about damaging anything if I put probes on the wrong ones?

Scott,
Checking for current is more complicated than checking the resistance of the heating element. So - there is more potential for damage, including the meter itself if it not designed for the rather high current of a heating element and it puts you in closer contact with live household current.

If I could recommend, follow this rule of thumb, do the easiest thing first.

1) Power up the trailer and turn on the heater: the heater circuit breaker and switch. If there is no water in the tank then do the next step with some haste. Measure the voltage across the heating element terminals. Confirm you are seeing around 110-120V. on the AC setting on the meter. If not, you will have to troubleshoot the switches, thermostat and various connections. Come back to us at this point. If you do have voltage where there should be voltage then you are down to one last step.

2) If proper voltage is at the heating element then next test the resistance of the element:
STOP HERE! Pull the trailer power cord out of the socket and bring one end to where you are working. So no one accidentally - helpfully - plugs the power back in without your knowledge. Next, disconnect one of the two wires at the element. This is optional but I highly recommend it. Switch the meter to resistance, lowest scale and confirm 10 to 20 Ohms between the two element connectors. If way higher (infinite or close) then go to Amazon and order a new element. You found your problem and there is no ambiguity at this point.

Originally Posted by steve dunham
ALWAYS ASSUME A CIRCUIT IS ENERGIZED AND ACT ACCORDINGLY !!

--
Alan

[steve dunham]

You could put an amprobe ( clamp on amp meter ) around the circuit conductor feeding the water heater at the circuit breaker panel .
It won't tell you anything because there is no current flow
If there was current flow through the element the water would be hot !!
You are looking for voltage , not current , ( they are not synonymous) all you need is a simple volt meter
You can do all the tests required including checking element continuity with a volt meter.
I did troubleshouting for years with a simple Wiggy.
A $10 solenoid style tester.

[sclifrickson]

Ok, so I finally put my multimeter onto the heating element, and this is what I've found:

1. (With power disconnected) I get 10.6 ohms resistance. So the element is ok, right? I was actually hoping for a bad element as I think this would be easiest to fix.

2. With AC on, I get 0V AC at the element. Bummer.

So a switch or wiring is bad, yes? How do I isolate and test these components?

[Brian B-P]

Originally Posted by sclifrickson

1. (With power disconnected) I get 10.6 ohms resistance. So the element is ok, right?

P=V²/R, so with V=120 volts and R=10.6 ohms, that's 1360 watts. Resistance will change a bit with temperature, but this is certainly appropriate... so the element seems okay to me.

[steve dunham]

Make one more test. With the circuit breaker to the water heater turned to the OFF position , and the wires hooked up to the element, take an ohm meter and read from the white wire at the element to the equipment ground. You should get a reading of less than one ohm. If the meter gives you a high reading or infinity there is a problem with the neutral. ( Assuming the element is good)
The element will not work without a hot or without a neutral.
It needs both conductors.

** The unit work switch is a known source of problems with these water heaters **

[Ron in BC]

OK, you've done some checks and nothing seems amiss.

I have one trouble shooting saying that's served me well over the years. Never assume anything. You've flipped the breaker and one would assume that the circuit is now powered up. It probably is sending current to the switch but confirm that first. Remove the panel cover. Put one probe of the meter on the breaker terminal and the other on the white neutral terminal block. Confirm that you have 110 volts coming out of the breaker, don't rely on it being "on".

If you have 110 at the breaker it's very unlikely that you have a break in the 110 wiring. I'd check the switch next.

Ron

[sclifrickson]

I finally got around to pulling and testing the on/off switch on the heater itself. That was the culprit. A new switch from the Home Depot and all is well again!

Thank you to all for your assistance!