Richmond Water Heater Woes

[ChrissyG]

I've been fighting with this hot water heater for a few days now and it has boggled my mind, and everybody who I've talked to. It's a Richmond 240v that's about 3 years old. So here's the story.

I came home the other night and the breaker was tripped (it is a twin

20 amp breaker). When I tried to reset the breaker it wouldn't lock in the 'on' position. So I figured it was a bad breaker. Not too uncommon considering the mobile home is 17 years old and it was original. So I replace the questionable breaker and reset it. I waited for about 45 minutes and nothing happened.

So I go to the hot water heater and notice one of the hot wire connections was melted where the wire nut connection was. I cut, clean, and reconnect the wires with a new nut. Waited for an hour, and there was still no hot water. So I decide it's time to install a kit.

I killed the power, drained the tank, and removed the elements. They are 240v 4500w elements. I go to the hardware store and match up the size and wattage. I got the whole kit which included elements, upper and lower thermostats. It was like $7 more than buying the elements only. So I come home, cleaned out the lime, and install the elements and thermostats. I turned the water back on and filled the tank up and waited... Guess what! No hot water. I later found out that I made a mistake and didn't let the air out of the tank. So I figured well this is going to be one of those $20 lessons.

I go back to the hardware store and get another set of elements and installed them. I even checked the dip tube to make sure it was good. This time I made sure that there was water at the pop-off valve on top. Turned on the power, and waited an hour. No hot water.

Now I'm starting to get frustrated. I break out my handy multimeter and start checking the voltages. I'm reading 120v at all the connections and at both elements. I turned the power off and I'm getting continuity through all of the wires and the tank as the common ground.

I even ran another wire from my service panel to the water heater to make sure I had a good power source. Still no heating.

So I'm completely stumped now and I was wondering if you all could suggest something that I've over looked. I know it's POSSIBLE that I got two bad sets of elements, but it's not probable.

I look forward to your responses so I can take a hot shower tonight.

- Jim

[trader4]

You say the element is 4500W @ 240V. That means it should have a resistance of 12.8 ohms which you can check with your meter. Then, if it's connected to the circuit and you measure 240V across it, it's heating. If it doesn't have 240V across it, trace back to the problem.

With a 20amp breaker, the thermostats must be wired so that only one element is on at a time, as it will be pulling 18.8 amps. Also, I think that as it currently is wiered is an NEC code violation, as I think for a continuous load, the actual load is supposed to be a max of 80% of the breaker.

[Speedy Jim]

QUOTE: "I'm reading 120v at all the connections and at both elements. "

There is one measurement you did not make: Connect the meter across the 2 Lines coming in to the heater (from the breaker).

If you read ZERO Volts, one side of the incoming

240V is dead/open. You would have to backtrack further to find out where it becomes dead/open.

t'other Jim

[RBM]

The first thing you should have done is broken out the multi meter. If the heater has 4500 watt elements, it requires a 30 amp #10 feed cable and a double pole 25 or 30 amp breaker. Because the existing 20 amp breaker was being loaded to the max, I'm guessing it went bad. I question if the replacement twin breaker you got was a double pole breaker or a twin single pole breaker. With the wires disconnected from the breaker and the breaker turned on, check with your meter across the two terminals to see that you have 240 volt. If not, your problem is at the breaker not the tank

[ChrissyG]

This is the breaker I replaced it with.

The old breaker was a combined 20 and 30 amp in this configuration. The two 20 amps were on the outside and connected with a metal band, and the 30s were on the inside.

Thanks for the help.

- Jim

[Speedy Jim]

And the voltage you measure between the 2 terminals on the new breaker is ... ?

[RBM]

You know what it is Jim, "0". Chrissy, you got the wrong breaker, you need another quad.

[RBM]

I don't know what the conductor size is, but you need thirty amps for the water heater. The quad breaker gives you 240 volts across the two inner terminals, and 240 volts across the two outer terminals. You can't replace it with two like you show in your link, although they could be made to work

[Jeff Wisnia]

I theenk I see where the OP went wrong.....

The "BD2020" is a "single pole" breaker, and thus both of the output leads come from the same phase of the line, so there's zero voltage between them.

His old breaker must have been a "two pole" one, so 220 volts was made available between the two outputs.

Chances are he didn't need much of the stuff he bought and bothered to install in the heater (twice), just the correct kind of breaker, huh?

See the page he referenced for the BD2020:

and click on the link for "Catalog Cut Sheets"

You'll see it's a single pole unit.

(A little knowledge is a dangerous thing.)

Jeff