marissa2
Senior Member
- Location
- Connecticut
The 25 amp breaker is OK but as stated the wire should be #10.
Lou
Lou
Hot water heater
- Thread starter jm1470
- Start date
- Status
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
NOT SHOULD it must be #10 for this use
Cavie
Senior Member
- Location
- SW Florida
Before most of Florida did away with local amenments, many inspectors called for #10 wire on 25 amp breakers.
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
Actually Collier county wanted 30 amp breaker and #10 and demanded dryer cord and receptacle many years ago. Glad they finally figured out why that was wrong.
jwelectric
Senior Member
- Location
- North Carolina
For what it is worth to anyone wanting to read this post my 40 gallon water heater is wired with #10 and has been on a 20 amp breaker for over 3 years without problems.
The day it trips is the day I will address the problem and not until then. As some of you already know I am lazy and just can?t mustard the energy to climb down the stairs and remove the panel cover just to change something that is working.
The day it trips is the day I will address the problem and not until then. As some of you already know I am lazy and just can?t mustard the energy to climb down the stairs and remove the panel cover just to change something that is working.
Jim W in Tampa
Senior Member
- Location
- Tampa Florida
Gallons is not important. What size are elements ? If 3500 then its fine as is
kbsparky
Senior Member
- Location
- Delmarva, USA
Change the circuit to 120 Volts. At 1125 watts, a #12 wire on a 20 Amp breaker is more than adequate. 
Unless they use a lot of hot water in a short time span, they will never notice the difference.
Unless they use a lot of hot water in a short time span, they will never notice the difference.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I think Mikes point is that at 4500 watts the water heater will only draw 19 amps and it will work fine on a 20 amp circuit. Rarely are water heaters running for 3 hours or longer.
jwelectric
Senior Member
- Location
- North Carolina
Not a plumber but I don't believe that you can purchase a 40 gallon heater with 3.5kw elements.
Mine are 4kw elements and it hasn't tripped in over three years. The wife fills the whirlpool tub all the time and when she does she only uses the hot water side and this makes the temp of the water just what she wants. This tub holds 65 gallons of water in one filling.
This also means that the water heater tank is emptied each and every time and has to heat 40 gallons of water from about 40 degrees from the well to a piping 120 degrees
The use of a 30 amp breaker on most water heaters is by permission and not a requirement.
422.11(E) Single Non–motor-Operated Appliance. If the branch circuit supplies a single non–motor-operated appliance, the rating of overcurrent protection shall comply with the following:
(3) Not exceed 150 percent of the appliance rated current if the overcurrent protection rating is not marked and the appliance is rated over 13.3 amperes. Where 150 percent of the appliance rating does not correspond to a standard overcurrent device ampere rating, the next higher standard rating shall be permitted.
To follow 422.13-
422.13 Storage-Type Water Heaters.
A fixed storage-type water heater that has a capacity of 450 L (120 gal) or less shall be considered a continuous load for the purposes of sizing branch circuits.
A 25 amp breaker is all that is required.
Having stood in front of electricians and electrical inspectors for nine years I ask many times why we use a 30 amp breaker on water heaters. 99.9% of the answers I hear are, “because it is a #10 wire.”
Most don’t have a clue of Section 422.11 of the NEC.
EDITED TO ADD:
And see what Dennis said above
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