Water Heater Elements

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ote

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I did a service call today at a hair salon and found the breaker disconnect at the water heater was burnt up. The line side terminals and about three inches of the line side wiring to the breaker were toast. The owner needed hot water and it was too late in the day to get a new disconnect, so I bypassed the disconnect with 10-2 romex to get her hot water. The feed was romex and was being fed from a 200amp panel and 30a breaker about 50ft away. I will return tomorrow with new disconnect. My question is: After re-energizing the circuit, I Put an amp meter across each leg and it was pulling 33.9 amps. I checked the voltage and it was 239v. I then looked for a sticker on the water heater and found it had been torn away or fell off. I opened the access panels to the elements and found both elements were energized at the same time. The upper element was 3500w and the lower was too difficult to see. After about 20min. the amperage dropped to 19.2amps and then 10min. later dropped to zero. This water heater apeared to be about 40gal, just your typical house style water heater and about 5-7 yrs old. The owner said the water heater was a quick recovery type. I've never seen a water heater that both elements are energized at the same time and I'm concerned about the amp draw. Is this normal for a quick recovery water heater?? or is there something else with the t-stats going on??
 
Around here the POCO will not allow both elements on a residential to be energize. If the unit is designed that way then you obviously have the wrong wiring for it. I suggest you look closer and see if someone didn't replace the upper thermostat with the wrong one. The upper T-stat should be a spdt. I bet it is just a sp like the bottom one.
 
ote said:
I did a service call today at a hair salon and found the breaker disconnect at the water heater was burnt up. The line side terminals and about three inches of the line side wiring to the breaker were toast. The owner needed hot water and it was too late in the day to get a new disconnect, so I bypassed the disconnect with 10-2 romex to get her hot water. The feed was romex and was being fed from a 200amp panel and 30a breaker about 50ft away. I will return tomorrow with new disconnect. My question is: After re-energizing the circuit, I Put an amp meter across each leg and it was pulling 33.9 amps. I checked the voltage and it was 239v. I then looked for a sticker on the water heater and found it had been torn away or fell off. I opened the access panels to the elements and found both elements were energized at the same time. The upper element was 3500w and the lower was too difficult to see. After about 20min. the amperage dropped to 19.2amps and then 10min. later dropped to zero. This water heater apeared to be about 40gal, just your typical house style water heater and about 5-7 yrs old. The owner said the water heater was a quick recovery type. I've never seen a water heater that both elements are energized at the same time and I'm concerned about the amp draw. Is this normal for a quick recovery water heater?? or is there something else with the t-stats going on??
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That's quite normal. As far as your line side being toast, there's something alot larger at hand there:confused:
 
76nemo said:
That's quite normal. As far as your line side being toast, there's something alot larger at hand there:confused:
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It is not normal for both elements to come on together-- not that I know about anyway. and 33.9 amps isn't normal on a 30 amp circuit.
 
water heater elements

water heater elements

Does anybody have a wiring diagram for the way the elements should be connected - haven't dealt with many water heaters.........
 
Try this....

EWiringDiagram.jpg
 
I would say the factory wiring has been tampered with, the water heater was not keeping up, so some smarty has changed the internal wiring to allow both elements to be energized.
 
water heater elements

water heater elements

Thanks Dennis for the diagram- I'm betting someone rewired the bottom element to stay energized together with the top one- I'll find out tomorrow. Think I'll pick up a new top t-stat just in case.
 
water heater elements

water heater elements

I think Hillbilly is right on that one. Now what am I going to tell the owner when her water doesn't heat up as fast as it used too especially when she uses this for her hair salon????
 
I usually just replace everything on a water heater call. Parts are cheap, labor to return and fix it again is not.
 
hillbilly1 said:
I would say the factory wiring has been tampered with, the water heater was not keeping up, so some smarty has changed the internal wiring to allow both elements to be energized.
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There are simultaneous water heaters available. They operate just as the OP stated the one he was working on did. I would guess whoever installed it didn't bother to check the electrical requirements.
 
ote said:
Now what am I going to tell the owner when her water doesn't heat up as fast as it used too especially when she uses this for her hair salon????
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Tell her the new breaker/disco won't heat up as fast, either. ;)
 
Disconnect the wires from the elements and ohm them out. A 4500 watt element is usually around 13 ohms. If one is shorted, it can cause crazy amp readings.
 
Water Heater Elements

Doing some calculations, if the top element was 3500w and the bottom (guessing here) was 4500w the the two added are 8000w. 8000w devided by 239v (actual reading) is 33.47amps. Pretty close to what I was reading with amprobe. When the upper turned off, I was reading 19.2amps, which is pretty close to the 18.82calculated amps. My next question is: How can I tell if this water heater was designed to run both elements at the same time or not without any nameplate?. I can change the circuit if I have to, just don't know how to tell if someone improperly re-wired t-stats or if WH was designed to run both at the same time?????
 
ote said:
How can I tell if this water heater was designed to run both elements at the same time or not without any nameplate?. I can change the circuit if I have to, just don't know how to tell if someone improperly re-wired t-stats or if WH was designed to run both at the same time?????
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I take it there are no part numbers visible?
Do you know the Manuf

I personally never have seen a water heater such as yours with both elements running at the same time.
What Size are the conductors in the WH if they are #12 I can bet you it's not rated for such.
 
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