Water Heaters - Water Heater Wiring Question

I installed a new water heater in our new house that I'm building. I successfully wired the entire house but the water heater is giving me trouble.

I had a 40 gallon electric water heater and wired it up with two hot 120vt leads from a double pole 30 amp breaker. Each wire showed 120volts. Copper wire is grounded to the water heater to the designated place. I used 8/3 wire so the white wire is just capped.

Water heater is full of water and I made sure to fill it before turning power on. I also double checked to make sure plumbing is correct.

I don't seem to get any hot water. I replaced the water heater with another thinking that *maybe* the water heater was bad from the factory (I know, it's a stretch). New one doesn't seem to be heating up either. How long should I expect it to take to heat water initially? After a couple hours there is no sign of even luke warm water.

I tested each element and each element has two poles on it. Each pole reads 120 volts. Power seems to be everywhere it needs to be. Should I get a 240 volt reading anywhere? (It's a 240volt water heater)

Any information would be very welcomed!! Thanks

You should get 240 volts between the two supply wires, and 120 from one to a ground. It takes a while to get hot water, but you should be able to feel lukewarm water after an hour or so. Make sure the breaker button is pushed in on the top element. And I am assuming you didn't mess with the wiring of the elements or their thermostats, right?

Right. I checked each line to ground and it was 120. I'll check line to line tomorrow to ensure 240 between the 2. But yes, it's been about three hours and no sign of even luke warm water.

I must be doing something wrong since this is the second WH and I have the same issue. I'm wondering if I could have possible gotten the wrong breaker. It says 30 amps and the two poles are tied together (so that you can't engage just one side of the breaker)

Voltage will travel through the heating element and back up the other lead making it look like you have 120v on both sides of the electric pathway. But, it is the same leg of the circuit so it will not make the elements energize.

Use a volt meter and start at the top. You should have 220 between the two 'hot' wires you came in with, then at the top of the high temp limit switch. Continuing down you should have 220 on the bottom of the limit switch. If not, there is a red button in the middle of that limit switch. It is a reset button that you can depress. Careful, I use a screwdriver! If you have 220 on the bottom continue down to the thermostat.

This is where the wiring can go astray. Normally, the top element will fire first, and when the top half of the tank is hot, the thermostat will turn off, but all it really does it direct the electricity down to the bottom element. If the bottom thermostat is on, then the bottom element will energize and heat the lower half of the tank. The bottom element is a simple off/on thermostat. So, if you have cold water in your tank then only expect 200v to the top element.

If you have 220 across any two connections on the top element look and see where the wires go. They should go to the top element. Check voltage across the element. There should be 220v. If so, you will now have to change to an amprobe. Clamp around either wire while on a 0-40 amp scale. You should see about 20 amps, depending on the size of the element. If you have 220v across the element but no amps then your element is bad.

Voltage will travel through the heating element and back up the other lead making it look like you have 120v on both sides of the electric pathway. But, it is the same leg of the circuit so it will not make the elements energize.

Use a volt meter and start at the top. You should have 220 between the two 'hot' wires you came in with, then at the top of the high temp limit switch. Continuing down you should have 220 on the bottom of the limit switch. If not, there is a red button in the middle of that limit switch. It is a reset button that you can depress. Careful, I use a screwdriver! If you have 220 on the bottom continue down to the thermostat.

This is where the wiring can go astray. Normally, the top element will fire first, and when the top half of the tank is hot, the thermostat will turn off, but all it really does it direct the electricity down to the bottom element. If the bottom thermostat is on, then the bottom element will energize and heat the lower half of the tank. The bottom element is a simple off/on thermostat. So, if you have cold water in your tank then only expect 200v to the top element.

If you have 220 across any two connections on the top element look and see where the wires go. They should go to the top element. Check voltage across the element. There should be 220v. If so, you will now have to change to an amprobe. Clamp around either wire while on a 0-40 amp scale. You should see about 20 amps, depending on the size of the element. If you have 220v across the element but no amps then your element is bad.

I must have the wrong type of breaker. I took the OHM meter and used the same setting that I used when I tested each line separately (and had 120 on each feed from the electrical panel. If I understood your directions correctly, I then disconnected the two wires from the water heater and put one lead from the multimeter on line 1 from the panel and the other multimeter lead on line 2. Did you say I should see a reading of 220? I don't get anything, just a "minus" sign.

Yeah, you should be using a two pole circuit breaker. It looks like two circuit breakers that are glued together, and the trips are locked together so that when one trips it pulls the other off as well.

When in the circuit panel, and on, you should have 220v between the two. One wire to each, plus a green wire goes to the water heater. The green wire from the ground or neutral strip goes to a green wire on the heater and the two wires from the breakers go on the two wires that are on the top two screws on the high limit switch.

Yeah, you should be using a two pole circuit breaker. It looks like two circuit breakers that are glued together, and the trips are locked together so that when one trips it pulls the other off as well.

When in the circuit panel, and on, you should have 220v between the two. One wire to each, plus a green wire goes to the water heater. The green wire from the ground or neutral strip goes to a green wire on the heater and the two wires from the breakers go on the two wires that are on the top two screws on the high limit switch.

Thanks MDTaylor. The double pole breaker was bad. When I opened the panel and tested for 240, I didn't get anything. I replaced the breaker and now it's all working. I really appreciate the help!!!!!

This forum saved me! :)