Hubbell Electric Heater Company WATER HEATER DF - Manual (Page 13)

13
ELECTRICAL CONNECTIONS
Electrical connections to the water heater should conform to the National Electrical Code or the code
legally authorized in your locality. A fused disconnect switch should be used in the burner control
circuit. The contractor shall run the properly sized electrical service to the terminals indicated on
burner wiring diagram. Refer to burner manufacturer's manual for specific electrical requirements.
VENTING
This non-condensing water heater is designed to exhaust into its own independent vent or into an
existing vent system that serves other appliances. In all cases, a negative pressure must be
maintained within the venting system to prevent the leakage of combustion products.
Several basic venting rules must always be followed.
1. The vent must be independently supported so its weight does not bear on the water heater's
flue collector.
2. The vent must never be sized smaller than the flue collector outlet. It can be up to two sizes
larger but, in all cases, must be sized in accordance with National Fuel Gas Code
Requirements given the particular installations vent configuration and water heater input rate.
3. When a relatively high negative draft occurs in a vent, a draft regulator sized to the vent
diameter should be installed and adjusted to begin opening at a negative draft of -0.1 in.
W.C. A draft regulator should be installed no further than two feet away from the water
heater flue outlet.
4. A vent must never be welded to the flue collector outlet.
5. All vents must be constructed in accordance with the National Fuel Gas Code and terminated
on the outside of the building using a UL listed vent cap. Horizontal venting through an
outside wall is acceptable, but an induction blower may be needed to maintain a negative
draft in the vent.
If the water heater is vented into an existing overhead vent (or breaching), it is recommended the
vent be designed for positive pressure in case there is positive pressure in the overhead vent.