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Author:
etbrown4 (NC)
Been doing plumbing and electrical work for nearly 40 years and here is a new one for me.
50 gal elec water heater, maybe 3 years old. Rated 4500w
It is pulling 18a on both hot wires supplying the heater so that's at 230v, measured by an Amprobe.
There is no leak and the T&P is not leaking either.
One wonders how a heater can draw it's rated current and not heat water.
Elements test ok. Resets are not tripped.
I know there can be issues with broken dip tubes and cross connections, but can't really see how either could apply here.
I also know that the situation I describe should be a physical impossibility, as current drawn is current used, and will yield an equivalent amount of heat into that water!
Tips appreciated
Water Heater Pulling 18 Amps Continuously - Not Heating
Edited 1 times.
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Author:
etbrown4 (NC)
It becomes more complex...
230v measured across top element when powered on. Checked with 2 different meters.
Top element powers on first.
Resistance across both elements is 12.8 ohms.
18 amps still being consumed by top element....checked with 2 Amprobes.
Neither element is grounded to the frame.
The heater displays no sign of heat, top or bottom, and after an hour of consuming 18a, the hot side is cold. and yes, I know that the problem described is in theory, impossible. If it was an easy one, I would not have posted it.
Hum.............. where is that current going? It has to result in heat. ..or a bad reading somewhere.
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Author:
george 7941 (Canada)
The Amprobes you are measuring current with - are they clampmeters?
You are not measuring some parameter correctly, whether current or voltage.
Is the 18.5 amp current steady or does it vary at all?
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Author:
bernabeu (SC)
have you ruled out the possibility of a water leak which is 'drawing off' the actual hot water ?
==============================================
"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638
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Author:
etbrown4 (NC)
the previous poster was right on the money! thanks
Old man winter caused this one.
This property has a pool equipment room and outside shower which is remote from the house.
The Pool man came yesterday and turned on water to that equipment room and left.
Our sub zero winter froze a 1/2" cpvc hot water line in that remote location, though the water supply had been off for the winter. Unbeknownst to everyone, the hot water ran all night long, making the water heater seem as if it was not heating...when it was.
Sure enough the 18amp draw was right, watts were consumed! The leak was small enough and the flow moderate enough that at the heater there was no perceptible sound of water flowing. The sound at the heater was just the normal sound of the element being on.
We chased a similar ghost 25 years ago with a sneaky T&P valve leaking. In that case it was a similar slow leak, but still enough to cool the hot water. In that case the outlet for the t&p exited two floors below outside of another condo unit, so similarly we never saw the outflow until many hours later.
Thanks for all the tips! All contributions appreciated.
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Author:
hj (AZ)
The current is heating the water. Your problem, even if you do not think you have a leak, is that the water IS leaking out faster than the heater can accumulate it. You would not be the first person to replace a good heater and find out the new one is doing the same thing. I have even had plumbers do it.
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