Home Size Southern climate: 2 bathrooms
Northern climate: 1.5 bathrooms
Indoor Unit Dimensions 20.5” (H) x 13.8” (W) x 6.7” (D)
Outdoor Unit Dimensions 20.5” (H) x 13.8” (W) x 6.7” (D)
Weight 36 lbs.
Gas Consumption
(NG & LP)
Max. 140,000 Btuh - Min. 20,000 Btuh
Capacity Range 0.5-6.6 Gal./min.
Energy Factor SV: 0.82 (NG), 0.84 (LP)
OD: 0.83 (NG), 0.86 (LP)
Thermal Efficiency 83%
Temperature Settings 100-150° F (in 5° F Intervals) 160° F
Accessories SV: Anchoring Screws, Power Cord
OD: Anchoring Screws



Owner's Manual




Our NR66 series is perfect for apartments, condominiums and townhouses with 1-2 showers. When properly sized, they provide an endless supply of hot water and are designed to be more efficient than traditional tank-type water heaters. These compact heaters will save space without compromising power. Built-in features include safety lock-out, freeze protection, and high elevation adjustment. PVC CANNOT be used for venting.

These units also offer several innovations:
Safety lock out - Default max. 120 degrees (refer to owner's manual for higher temp)
Standard burner - High performance single flame burner.
Fully modulating burner - Automatically adjusts burner level accordingly.
Turbo Flow - Up to 6.6 GPM @ 35° temperature rise (5.3 GPM @ 45° rise).
Direct ignition - No standby pilot light.
Thermal fuse - Automatic overheat protection system.
Resin coated PC board - Increases durability and protection from elements.
Automatic air regulator - Monitors internal temperature/maximizes burner efficiency.
Resin coated PC board - Increases durability and protection from elements.

Natural Gas (NG) Propane (LP)
NR66-SV Indoor/Outdoor 12yr/5yr parts/1yr labor 0.82 0.84
NR66-OD Outdoor 12yr/5yr parts/1yr labor 0.83 0.84

*Energy Factor (EF) is a measurement of relative energy efficiency for a water heater; the higher the EF, the more energy efficient the water heater.

>> Available in Natural Gas (NG) and Propane (LP) models only.
>> Temperature Settings: 100-160oF (12 options)
>> Thermal efficiency for all models: 83%
>> Self-diagnostic onboard computer system
>> Battery back-up compatible
>> Recirculation compatible
>> WARNING!!! PVC cannot be used for venting. Only Category III (3" stainless steel venting).

>> Accessories
Isolation valves (#IK-WV-200-1-TH or #IK-WV-200-1-SW)
Outdoor vent cap (#VC-3) for NR66-SV model only.
Pipe cover (#PC-1S)
Remote controller (#RC-7649M; for Canada #RC-7650M)
Remote controller cord (10 ft.: #RC-CORD10; 26 ft.: #RC-CORD26)
Remote controller outdoor junction box (#0700757)
Recess Box (#RB-500) for NR66-OD model only.
H2FLOW Anti-Scale System (#H2F)