TOPIC: Wire size for Hot water heater

Not sure if I should call this out, but it doesn't sound right-I reported on an electric hot water tank that has 12 awg wire to power it. I believe 12awg is only good for 20 amps, the breaker is 30amps (240V). I'm sure it would be easier for the homeowner to change the breaker to 20amp instead of running new wire, but I don't think 20amps is good for a water tank? I don't want to nit pick either, and this has apparently worked okay since 1995 when the house was built. Should this be called out?

I would call it out as the wire should match the breaker. I would believe the 20 amp wire is to small and 30 amp makes more sense to me.

Was there a disconnect in sight?

Did the data plate of the water heater have any information on the electrical? This should state the size of the wire/breaker.

David, I failed to record the nameplate info from the water tank, but I would assume it would need to be 30 amps. This is the same house with the ductwork in the garage. There is no disconnect, only the breaker, which is in the garage adjacent to the laundry area. Most of the wiring seemed okay, I can't understand why someone would consider using 12 gauge for a 240volt 30 amp device, but as I say in the business "I'm never surprised yet always amazed at what people do"! I just didn't want to sound like I was nit-picking, but I believe this undersized wire/oversized breaker is a fire hazard.

How many volts is the service 220 or 240 VAC? Makes a difference.

The rating is 240 volt, but that is never accurate, especially in some rural areas where I used to perform Standby Generator and Switchgear work. We used to see 220 Volt that measured from 217 to 232, and 240 volt measuring 231-248. I know that's crazy, but 3 phase was always cleaner and more accurate-230 measures 230, 277 would measure 277 and 480 would measure 480. Maybe the reason the wire was sized to 12 gauge was figuring higher voltage= less amperage?

There are plenty of water heaters that only require a minimum 20 amp circuit.  It could be this is a replacement water heater that needs 30 amps and they didn't pay attention to the wiring.  Too bad no data plate info.