Breaker Size

[walker]

Anyone know what size breaker this electric water heater would use?  It's a 120v

https://www.lowes.ca/products/view.aspx?sku=10932457

Couldn't find anything in the manual, unless I missed it.

[walker]

I'm guessing 30amp as it says to use 10AWG wire?

[Admin]

Maybe the rating plate will list the maximum overcurrent protection.

If you're installing it in a mobile home you can use a 15A breaker.

70-120 Branch circuits — Mobile homes
(3) Notwithstanding Rule 8-104, a circuit supplying an electric water heater having an input not more than 1500 W at 115 V or 3000 W at 230 V shall be permitted to have overcurrent protection rated or set at 15 A.

1500W / 120V = 12.5A

8-104 Maximum circuit loading
6) Where a fused switch or circuit breaker is marked for continuous operation at 80% of the ampere rating of its overcurrent devices, the continuous load as determined from the calculated load shall not exceed
(a) 80% of the rating of the circuit where the ampacity of the conductors is based on Column 2, 3, or 4 of Table 2 or 4; or

12.5A x 1.8 = 22.5A

Technically you can use a 25A breaker and #10 wire, but a 30A will also work.

14-104 Rating of overcurrent devices
(2) Except as provided for by Subrule (1)(c), the rating of overcurrent protection shall not exceed
(a) 15 A for No. 14 AWG copper conductors;
(b) 20 A for No. 12 AWG copper conductors;
(c) 30 A for No. 10 AWG copper conductors;
(d) 15 A for No. 12 AWG aluminum conductors; and
(e) 25 A for No. 10 AWG aluminum conductors.

[Porcupinepuffer]

If the manual wants you to use 10, I'd stick with that. I would also use a 15a breaker since the codes the admin posted says you can do so. If the breaker ends up tripping, there's something wrong with the tank.

I remember doing a lot of electric water heaters in the past. Never a 120v one. We would use #12 with the 3000w/240v tanks and a 20 a breaker... Every so often a customer would get the better quality tank that had the 4500w/240v heaters and we would go to #10 and a 30a breaker.

If the tank doesn't come with the plastic drain tube for the pressure relief, make sure you install one with the correct maximum distance from the floor.