How To Check Thermostat On Water Heater

How Practice I Troubleshoot My Electric Water Heater Thermostat?

An electrical thermostat will virtually likely have 2 thermostats, an upper and a lower thermostat. Both thermostats are concealed using a metal cover plate secured to the h2o heater using i or two screws.

The function of a water heater thermostat is to turn the power to the heating element on and off. It does that relative the water temperature within the water heater.

The upper thermostat is usually continued to the h2o heater reset button. In nearly water heaters, this is a red push button that is as well concealed past the cover plate.

A water heater reset push button which is also known equally an emergency cut off (ECO) switch cuts off power to the water heater (by tripping) in the event of an unsafe condition. This is most probable caused past a bad thermostat, short heating element or loose wiring.

Somethings yous may retrieve that the reason yous have no hot water is because of a bad thermostat, but the reset button may have tripped, especially if there was a power surge.

If at that place was a ability surge or the thermostat fails to plough off the heating element, the h2o temperature volition increase past the thermostat setting all the style to the reset button rating (180⁰ F) which will cause it to trip and turn off power to the heating element.

With a tripped reset push button, the h2o in the water heater will no longer exist heated and every bit a result you will take no hot water in the house.

If you have no hot water at all, you most likely have a bad upper thermostat while hot h2o that runs out fast is a sign of a bad lower thermostat. A h2o heater reset push that keeps tripping is also another sign of a bad thermostat.

To test a water heater thermostat, starting time past turning off power at the breaker then remove cover plates and insulation. Use a multimeter to exam for continuity betwixt 2 thermostat terminals. A adept thermostat should accept a reading of 0 ohms.

If the reading is more nix the thermostat will demand to exist replaced. While at it, accept your time to cheque if the reset push has tripped, and also test the heating element for continuity as well.

How to Test a Water Heater Thermostat with a Multimeter

A multimeter is used to test for continuity. Continuity basically tests whether an electrical current is open or closed. With a airtight circuit, current can flow through but it cannot flow through an open circuit.

Equally hard as it may sound, testing a water heater thermostat for continuity is actually pretty easy and fast. Y'all however need to do it safely every bit I will outline in this post.

To test if your water heater thermostat is bad, follow these steps:

1. Turn off Power to the Water Heater

Y'all cannot test a thermostat with power still flowing through it. There will most likely exist 240 volts flowing through the circuit which is plenty to electrocute you lot.

You tin plow off power to the water heater at the circuit breaker, unplugging it from the power outlet or both. I suggest that yous practice it at the breaker.

Your firm'south electrical panel will about likely be located in the garage, basement or in a storage closet. Look for the breaker labeled "Water Heater" and flip it to the off position.

2. Gain Admission to the Thermostat

Equally I mentioned earlier, your electric h2o heater volition have ii thermostats. Showtime with the upper thermostat.

Look for a cover plate (protruding outwards) secured to the water heater using ane or 2 screws.
Employ a screwdriver to remove the screws and place them a manner where you can't lose them.
Remove the insulation. You will see a piece of insulation that will be covering the thermostat and element. Remove information technology also. Y'all tin as well secure the insulation on the water heater using duct tape.
Virtually water heaters will have a plastic cover over the thermostat. Pull it out. The encompass snaps on the thermostat and heating chemical element.

water-heater-thermostat-and-heating-element

With the comprehend plate out of the fashion, you can now see the thermostat, reset button and heating element. The thermostat is the one at the top with a serial of screws and wires connected to it.

At the lesser you see will 2 wires connected to ii screws. That is the heating chemical element threaded on the tank. The reset button will be slightly above the heating element and will most likely exist a red push button.

You volition also run into the thermostat temperature aligning dial (looks similar a large plastic screw). This is used to adjust the temperature settings of the thermostat.

3. Inspect the Reset Push button

Equally I had mentioned earlier, the reason you lot could be having no hot water could be because the reset button has tripped. Although a tripped reset button could be caused by a bad thermostat, it could also be caused by a shorted heating element amid other electrical bug similar a power surge.

Bank check to see if the residual push button has tripped. A tripped reset push will have popped out all the manner.

To reset a tripped reset button, printing it inside until you hear it click. If it doesn't click, press and hold information technology for well-nigh 5 seconds.

Only doing that could be the solution to your h2o heater problem. I will however communication that you continue to test the thermostat and heating element even later on resetting the reset push.

four. Test the Thermostat for Continuity

Before doing annihilation, offset by taking a picture of the thermostat connections with your phone or digital camera. That way you will be in a position to remember which wire was connected where afterward.
Loosen the screws only a little and disconnect the wires.
Using a flathead screwdriver, turn the thermostat temperature adjustment dial to the highest (hottest) setting.
Prepare your multimeter. If you have an analogue multimeter, move the dial to the lowest ohms of resistance settings. To calibrate it, pinch the 2 probes together and suit the needle to read naught. ohms.
With a digital multimeter, motility the dial to the to the lowest degree ohms of resistance settings or better even so if you have a tone (indicated by a microphone symbol) move the dial at that place.
On the thermostat, you will see 4 sets of screws, 2 on the left and 2 on the correct. Place the ii multimeter probes on the left set of screws, one on top of the other. Check the reading on the multimeter.
Measure the resistance on the other sets of screws (the ones on the right).
Use your flathead screwdriver over again to movement the thermostat temperature dial to the everyman settings.
Repeat the examination above, with the left and correct thermostat terminals.

In both of the tests above, your multimeter should read zero ohms. Whatsoever other figure autonomously from that you accept a bad thermostat and it will demand to be replaced.

Get out the upper thermostat temperature aligning dial at the lowest setting and proceed to the exam the lower thermostat.
Remove the lower cover plate, insulation and plastic encompass as in a higher place and go fix to test it.

Note:As you will notice out, the upper thermostat and the lower thermostat are not identical. Carry this in listen if you will be replacing one of the 2 thermostats.

Arrange your lower thermostat to the everyman temperature setting.
Mensurate the resistance (continuity test) across the thermostat terminals. Note down your reading. You lot will notice that the lower thermostat has merely 2 terminals.

Testing the Water Heater Elements

As I said, the trouble with your h2o heater could also be acquired a shorted heating element. If the thermostats announced to be ok, I would advise that you examination the heating elements for continuity equally well.

Here is how you lot do information technology:

Start with the upper heating chemical element.
Disconnect the 2 wires on the screws.
Place the 2 multimeter probes on the screws and bank check the reading on the multimeter.
Move to the lower heating element and repeat the same.

A good heating element should have a resistance of between 10 and xvi ohms. If yous become a zero reading or one that is also depression then the heating element is faulty and will need to be replaced.

How to Supersede a Water Heater Thermostat

Replacing a thermostat is incredibly easy. The challenge might be in buying the correct 1. All thermostats are not universal.

You volition first need to determine if you lot have a single or dual-thermostat heater, and every bit I have already said, place if you need to supercede the upper or lower one.

I personally like to replace both thermostats at the same fourth dimension fifty-fifty if only one is faulty. There is high adventure of the 2nd i failing after the first ane. Replacing both of them will as well requite you piece of mind for the side by side few years.

You former thermostat will have the model number on it so you merely need to buy the aforementioned model, and preferably by the original water heater manufacturer.

Hither is how you lot replace a water heater thermostat:

Turn off power to the water heater.
Remove the cover plate, insulation and plastic cover.
Loosen the screws and disconnect the wires.
Pull out the thermostat. The thermostat is held in place by a metal bracket at the bottom. Gently pull the bracket outwards and lift off the thermostat.

Note: Be very careful with the bracket. Breaking it will mean that y'all will demand to buy a new water heater.

Insert the new thermostat where the old one was.
Carefully connect the wires as they were and tighten the screws
Put back the plastic comprehend, insulation and cover plate.
Turn on ability to the h2o heater.
Wait for about 20 minutes and bank check if your h2o is sufficiently heated.

If the problem was with your heating chemical element, replacing it likewise is easy but time consuming. Again I recommend that y'all replace both the heating elements as well.

To replace a h2o heater element, you will start demand to turn off power to information technology, shut off cold water supply, and drain the tank.
With the tank fully tuckered, disconnect the wires connected to the 2 heating element screws.
Employ a 1 ½ inch socket wrench to loosen the heating element and pull it out.
Supplant it with a new one and don't forget the washer.
Connect the wires backs to the screws and tighten the screws.
Fill the tank with water. Never plow on the ability with an empty tank. You will burn the new elements.
Once that tank is full make sure there are no leaks effectually the heating elements.
Put the cover and insulation back.
Power the water heater and wait for about 20 minutes for the h2o to get hot.

And basically that is how to test, troubleshoot and replace a h2o heater thermostat. I hope you are now sufficiently educated on the same.