Brand new water heater draws non stop 20 amps

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Matt Mckenzie

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Water heater draws non stop 20 amps. Service meter spinning fast and water heater constant draw 20 amps will not stop. All of a sudden an old water heater started drawing a non stop 20 amps. Brand new water heater was installed by the plumber. We let it fill all the way up before we energized the circuit. Circuit still draws a non stop 20 amps. The circuit is a 2 wire #10 with know grounding conductor (old school) does anybody have any idea what could be causing this?
 
You are continuously putting heat into the tank, it will eventually overheat if heat is not leaving the tank. Since it is not overheating that means water is flowing somewhere taking heat with it, find the leak in the hot water system or the item using hot water that you weren't aware of and you probably solve your problems.
 
Matt Mckenzie said:
Water heater draws non stop 20 amps. Service meter spinning fast and water heater constant draw 20 amps will not stop. All of a sudden an old water heater started drawing a non stop 20 amps. Brand new water heater was installed by the plumber. We let it fill all the way up before we energized the circuit. Circuit still draws a non stop 20 amps. The circuit is a 2 wire #10 with know grounding conductor (old school) does anybody have any idea what could be causing this?
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I would say the you have a leak in the hot water lines.

You didn't say how big the water heater is but I would assume 40-50 gal. You didn't say what the temp. setting is so I'll assume it factory setting. If it's drawing a constant 20 amps then sooner or later it will reach the temp setting, if it keeps going then sooner or later it will produce steam than then you will know it.
 
kwired said:
You are continuously putting heat into the tank, it will eventually overheat if heat is not leaving the tank. Since it is not overheating that means water is flowing somewhere taking heat with it, find the leak in the hot water system or the item using hot water that you weren't aware of and you probably solve your problems.
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I'm surprised the plumber wouldn't know about this.
 
How long did you measure the 20A draw? Is the water heater the only thing on that circuit? If there is any appreciable hot water demand, the heater will run continuously.
 
Matt Mckenzie said:
The circuit is a 2 wire #10 with know grounding conductor (old school) does anybody have any idea what could be causing this?
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The American educational system. Some children should be left behind. :dunce:

Just jokeing there Matt, English wasn't my best subject either. Still can speak it.
 
Matt Mckenzie said:
Water heater draws non stop 20 amps. Service meter spinning fast and water heater constant draw 20 amps will not stop. All of a sudden an old water heater started drawing a non stop 20 amps. Brand new water heater was installed by the plumber. We let it fill all the way up before we energized the circuit. Circuit still draws a non stop 20 amps. The circuit is a 2 wire #10 with know grounding conductor (old school) does anybody have any idea what could be causing this?
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Is the water meter spinning too?
 
growler said:
The American educational system. Some children should be left behind. :dunce:

Just jokeing there Matt, English wasn't my best subject either. Still can speak it.
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Probably auto-correct. It has failed me more then once.


My bet is in excessive use or leak in the hotwater system.
 
mbrooke said:
I agree, but if the heater draws 20amps 24/7 the high limit will either pop open or the T&P valve will leak water.
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Unless some or all of that current is going to earth and the energy is being dissipated in the dirt around the ground electrode rather than in the heater itself.
 
Matt Mckenzie said:
Water heater draws non stop 20 amps. Service meter spinning fast and water heater constant draw 20 amps will not stop. All of a sudden an old water heater started drawing a non stop 20 amps. Brand new water heater was installed by the plumber.
Click to expand...

mbrooke said:
My bet is in excessive use or leak in the hotwater system.
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mgookin said:
Maybe, maybe not. Easiest thing to check the water consumption and hope that's what it is.
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If it were my problem I would hope that it's a bad water heater. Then it's the plumbers problem.

I don't think there is much of a chance that an old water heater and a new one would have a mysterious problem that can't be explained. A water leak does explain the symptoms.

It's simple enough to check, just turn off all water usage and check the water meter. It probably won't be spinning that fast but it should be at a complete stop.

I check my water meter a few times a year to make sure that no leaks have developed. One of my customers had a $4K water bill because the leak was before the house and right at the meter. The water was running down to a small branch at the bottom of the hill and was not noticed. Those underground leaks can be expensive.
 
You are sure you have solid 240V. Have you measured voltage? Should not have a neutral so volts to ground is meaningless...you'll just read 120 on each leg even if one leg is open...you'll be reading through the heating element. Does voltage decrease across the element when the WH is on?
 
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High Z L-L fault?

recovery rate
+70 F
4500 W
27 gph or 1/2 gpm
anything great should keep the element on

he'll know when he gets his water bill lol
 
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GoldDigger said:
Unless some or all of that current is going to earth and the energy is being dissipated in the dirt around the ground electrode rather than in the heater itself.
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It could, but just seems unlikely to me. Not to say it cant happen. Fortunately that can be tested by amp clamping both hots at the same time at the panel.
 
20 amps into the dirt, maybe if it is a massive electrode, such as a CEE if it is a ground rod something tells me the dirt around the rod dries up some and current begins to decrease.

OP said there was same problem with old water heater and it was replaced. If drawing 20 amps that is 2400W @ 120 or 4800W @ 240, unless it is a million gallon tank it probably eventually either reaches a setpoint, kicks out the high limit, or starts to bleed pressure from the relief valve if there isn't heated water leaving the tank.

If it is a fault in wiring you should have a pretty good hot spot somewhere that should burn itself out or start a fire or both.
 
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