Education · Guidance · Support

AFFECTED MODELS

This tip applies to the AO Smith Cyclone, State Ultra Force, and American HCG series of commercial modulating gas water heaters.

REQUIREMENT

Each water heater needs its own dedicated electrical circuit. Sharing a circuit or breaker with other equipment, including a second water heater or a recirculation pump, is one of the more common causes of electrical malfunctions we see in the field.

It is also worth knowing that a shared circuit is outside of manufacturer requirements. In the event of an electrical failure, a non-dedicated circuit may affect warranty coverage, so getting this right at installation protects everyone.

ACCEPTABLE CONNECTIONS

The good news is that both hardwire and plug-in connections are acceptable. The circuit just needs to be dedicated and non-GFCI. This prevents electrical feedback and instability that can cause nuisance faults or control board failures.

SURGE PROTECTION

A surge protection device is recommended but not required. Given the cost of control boards on these units, it is a low-cost safeguard well worth including on any new installation.

EMERGENCY DISCONNECT

We also recommend including an accessible disconnect, whether a plug, switch, or breaker, at ground level and reachable without a ladder. Having a quick shutoff readily available is a simple step that can make a real difference in an emergency.

A FINAL NOTE ON CODE AND JURISDICTION

Always follow the requirements of the Authority Having Jurisdiction (AHJ) for your area. Where local code and manufacturer installation requirements differ, the most stringent requirement applies. When in doubt, go with whichever sets the higher standard. That approach keeps the installation safe, code-compliant, and covered.

As always, we are here to help. Reach out to the Factory Support Team with any questions!

Hugh M. Cunningham Companies | Factory Support Team
FST@hughcunningham.com