How To Determine What Gauge Wire Is Needed For My Atwood Water Heater

Published 09/01/2022

Products Featured in This Question

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

4" Carbon Fiber Digital Caliper

(26)

$12.46

Question:

I have a couple of melted wires/connections for an Atwood GC6AA-9E water heater. I can’t find replacement wires so I want to build my own. Wondering what gauge of wire I would need to make these wire connections. They come from the back of the water heater, electric side. Thanks

asked by: Jeff

Expert Reply:

When it come to wiring your Atwood GC6AA-9E hot water heater, you're going to want to go with a wire that's sized to accommodate the heater's current requirement.

For example, a 20-amp hot water heater needs 12-gauge wire, a 25-amp hot water heater requires 10-gauge wire, and a 30- to 40-amp hot water heater requires 8-gauge wire. Some large heaters draw up to 50 amps, requiring 6-gauge wire.

From the pictures it does appear that you have 10 AWG wire like # 10-1-1, however to be certain you can use a set of calipers # PTW80157 and measure the diameter of a single strand, then multiply by itself, and then multiply by the amount of strands of the wire.

For instance, if you measured 0.005" for the wire diameter, you'd multiply by itself (0.005" x 0.005" = 0.00025").

From here you'd multiply that value by the number of strands; i.e, 21 (0.00025" x 21 = 0.000525). This number is called the Circular Mils value of stranded wire, and is what you need to tell you what size wire you have. So, the example wire has 21 strands, with a Circular Mils value of 525, which corresponds to an AWG of 22.

You can easily find these charts anywhere online, and will have all the info you need to find the correct wire.