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NCC1991 Condensing Commercial Tankless Water Heater

by Noritz


Noritz Tankless water heaters provide a continuous flow of hot water, so there's no need to suffer through a cold shower if you're the last one out of bed, and there will always be plenty of hot water instantly ready for other uses when you're done. The hot water is always there when you need it with a tankless water heater, unlike with a conventional tank-type water heater, and with a tankless water heater, water is heated as it passes through the unit so you will always be using a fresh supply of perfectly heated water.

Noritz NCC1991 Series Condensing Tankless Water Heaters

Noritz tankless water heater
These tankless water heaters feature:
  • Recaptures the heat from the exhaust and uses it to preheat incoming water before passing it through the main copper heat exchanger, allowing this model to heat more water without using more fuel
  • Efficient use of waste heat to preheat incoming water also cools the exhaust gasses, allowing this unit to be used with PVC venting material
  • Designed to provide endless hot water for residential or commercial applications
  • Direct vent (DV) models draw air from the outdoors so they do not use any air from the indoor installation location, making them ideal for tight spaces or where indoor air is unsuitable for combustion
  • Adding a quick-connect cable allows the installer to quickly and easily connect 2 identical units to double the hot water flow rate
  • Also designed to work with a multi-unit system controller to connect up to 24 units to meet even greater hot water demands
  • Built-in neutralizing system for condensation means less wear and tear on heat exchanger
  • Direct ignition means no standby pilot light to waste energy
  • Commercial grade heat exchangers and fully modulated burner work together to provide increased efficiency, stabilize temperature fluctuations, and boost performance of the flow rate for long life under heavy use
  • Corrosion-free stainless steel casing protects the unit and allows for more efficient cleaning which reduces labor and maintenance costs
  • Self-diagnostic onboard computer system, combined with the included digital remote, provides ease of maintenance and temperature adjustment
  • 4" stainless steel vent pipe recommended
  • Dimensions: 24.4"h x 18.4"w x 9.4"d
  • View Specifications
  • View Flow Rate Chart

Model Description Natural Gas Propane
NCC1991-DV Direct Vent Tankless Water Heater $2,245.51 $2,244.41 Enter a quantity and
NCC1991-SV Indoor/Outdoor Tankless Water Heater $2,246.41 $2,261.47 Enter a quantity and
Due to size/weight and to ensure safe delivery, certain items ship by truck and have a $175 additional shipping fee per freight item.
Please select your type of address:
Commercial -or- Residential

Please note: For potential safety reasons, we do not recommend using PVC to vent gas tankless water heaters.
For the best results, we recommend using Category 3 stainless steel gas vent pipe for all gas tankless water heaters.


Accessories for Noritz Tankless Water Heaters

Use multi-unit controllers to connect commercial Noritz water heaters in series to satisfy greater hot water needs.
Use the Quick-Connect cord to connect two units, or a system controller for larger series of identical units.

Multi-Unit Connections for Model NCC1991

Description Price & Quantity
QC-2 Quick-Connect Cord - connects two identical units $29.75 Enter a quantity and
Multi-Unit System Controller for up to 6 units $311.74 Enter a quantity and
Multi-Unit System Controller for up to 12 units $929.75 Enter a quantity and
Multi-Unit System Controller for up to 24 units $1,699.49 Enter a quantity and

Brass Pressure Relief Valves

Image Description Size Price & Quantity
Pressure relief valve Brass Pressure Relief Valve
  • A pressure relief valve is required for all tankless water heaters. In some areas, a temperature and pressure relief valve is required. Check your local plumbing code for more information
3/4" FIPS x 3/4" MIPS $14.67 Enter a quantity and

Brass Temperature & Pressure Relief Valves

Image Description Size Material Price & Quantity
Pressure and temperature relief valve Brass Temperature and Pressure Relief Valve 3/4" FIPS x 3/4" MIPS FOR Potable Water $59.65 Enter a quantity and
3/4" FIPS x 3/4" MIPS NOT FOR Potable Water $13.95 Enter a quantity and

"The Isolator" Isolation Valves

Image Description Size Price & Quantity
Isolation valve set Isolation Valve - Set   (Hot & Cold) 
  • Includes pressure relief valve. Complete inlet/outlet valve system that provides everything you need for a secure installation including full port testing and flushing of the system with easy to install union connections. Includes pressure relief valve.
    2014 Federal Safe Drinking Water Act compliant
3/4" FIP Union x 3/4" FIP $99.62 Enter a quantity and
Isolation valve set Isolation Valve - Set   (Hot & Cold)  
  • Includes pressure relief valve. Complete inlet/outlet valve system that provides everything you need for a secure installation including full port testing and flushing of the system with easy to install union connections. Includes pressure relief valve.
    2014 Federal Safe Drinking Water Act compliant
3/4" FIP Union x 3/4" Sweat $99.42 Enter a quantity and

Gas Connectors

Image Description Size Price & Quantity
Stainless gasflex Stainless Gasflex 1" OD (3/4" ID) x 24"
with adapter to 3/4" FIP x 3/4" MIP
$36.33 Enter a quantity and
Gas ball valve Gas Ball Valve 3/4" $8.28 Enter a quantity and

Ball Valves

Image Description Size Price & Quantity
3/4inch ball valve FIP Ball Valve   3/4" FIP $13.64 Enter a quantity and
3/4inch ball valve sweat Ball Valve   3/4" Sweat $13.65 Enter a quantity and
Stainless steel nipple adapter Stainless Steel Nipple Adapter 3/4" MIP x 1-1/2" Long $3.97 Enter a quantity and
 Order 10, 50, 100 or more of the same item for additional savings!
Pricing discounts will show up in your shopping cart.

Flexible Corrugated Water Flexes

Image Description Material Size Length Price & Quantity
Stainless steel water heater flexes Flexible Corrugated Water Flex Stainless Steel 3/4" FIP x 3/4" FIP 18" $7.44
3/4" FIP x 3/4" FIP 24" $8.27 Enter a quantity and
Copper / Stainless Steel 3/4" FIP x 3/4" Nominal Sweat 18" $7.61
3/4" FIP x 3/4" Nominal Sweat 24" $8.34 Enter a quantity and

FloodStop Systems for Water Heaters

Features:
  • Easily prevent water damage from a leaking water heater with this unique device
  • The unit automatically shuts off water supply to the water heater and sounds an alarm leaving all other household fixtures and appliances operational
  • Provides additional protection by requiring AA batteries to be inserted to protect in case of a power outage (batteries not included)
  • Controller will operate normally without batetries installed but will continue to beep until they are inserted
  • Can easily be installed in fifteen muinutes
  • Full-port motorized ball valve (brass)
  • 2014 Federal Safe Drinking Water Act compliant
FloodStop Components:
  • Motorized Full-Port Ball Valve (3/4 inch NPT pipe threaded)
  • New Style Control Unit (with Battery Backup 4 X AA Size)
  • Water/Leak Sensor (1-1/4" X 7-1/2")
  • AC Power Adaptor (or use 4 X AA Batteries as Primary Power Source)
  • Output Contact Wires (2)

Model # Description Price & Quantity
FS 3/4-NPT-V4 Water Heater FloodStop System - 3/4" Pipe Threaded
Works with any 3/4" MIPT supply line - rated 0-180 psi
$149.95 Enter a quantity and
FS 3/4-C-V4 Water Heater FloodStop System - 3/4" Compression
Works with any 3/4" copper applications - rated 0-180 psi
$166.49 Enter a quantity and

Make sure to follow all of the manufacturer's instructions and directions by performing the proper maintenance and inspections
to ensure that you are fully protected from flooding - this is ever-so-important with (man-made) safety devices as they will eventually fail.


Related Items and Accessories



Common Plumbing Terms
FIP Female Iron Pipe (NPT threads)
MIP Male Iron Pipe (NPT threads)
NPT National Pipe Thread
FNPT Female National Pipe Thread
MNPT Male National Pipe Thread
Sweat Copper pipe solder fitting


Frequently Asked Questions

Q. "What does the term "temperature rise" mean?"
A. Temperature rise is the amount the heater raises the temperature of the incoming water, based on the flow rate shown of that water.

Q. "How does a tankless heater provide hot water without a storage tank?"
A. Tankless water heaters heat on demand. The water is heated as it flows through the unit. Automated valves control water and gas flow so that your water comes out at the temperature you set it to.

Q. "What's the difference between a conventional flue and a direct vent?"
A. A conventional flue is what most people are familiar with. It typically consists of a double-wall flue pipe going from the top of the heater through the roof, venting outside. The fixture draws its combustion air from the space around it (utility room, garage, hallway, etc.). A direct-vent unit vents and draws its combustion air through a specially designed pipe from the outside via an adjacent wall.

Q. "What make a condensing tankless water heater different?"
A. Noritz condensing water heaters use a dual heat exchanger system to increase efficiency by using the residual heat from the exhaust temperature, which is captured by the first, corrosion-resistant stainless steel heat exchanger, to preheat incoming water before it runs through the main commercial grade copper heat exchanger. This reduces carbon dioxide emissions and increases efficiency. This also means vented exhaust is lower in temperature than other tankless water heater designs.

Q. "Can I use PVC to vent these tankless water heaters?"
A. The idea of using PVC venting instead of Category III stainless steel venting for condensing tankless water heaters (never recommended by the water heater manufacturer for non-condensing units) is that it will save money on venting since the exhaust temperatures are specified by the manufacturer as within the capabilities of PVC to handle safely. However, we never recommend PVC for venting. In the real world, gas water heaters are rarely maintained to their ideal, which eventually results in raised exhaust temperatures. These raised exhaust temperatures will pass beyond what PVC can safely handle and overheated PVC can release dangerous fumes and even collapse as it fails. For this reason, there is a higher incident of dangerous issues associated with PVC venting on gas tankless water heaters and we cannot, in good conscience, recommend PVC venting for gas water heaters.

Q. "How does the Water Heater Scale Inhibitor System prevent corrosion?"
A. It forms a thin protective layer on the inside of pipes and metal parts. This film or layer is microscopic in thickness and will not build up over time.

Q. "What are the best reasons to install a Scale Inhibitor System?"
A. A Scale Inhibitor System helps protect the system by reducing scale buildup and adding to the longevity and efficiency of the heater.

Q. "What are low NOx emission requirements?"
A. NOx (nitrous oxide) refers to Nitrogen dioxide (NO2) and nitric oxide (NO) combinations (NO + NO2 = NOx) that are emitted in an exhaust system due to the result of the fuel burned to heat water. Many states are adopting low NOx laws that require instantaneous water heaters to meet an emission limit of 14 nanograms of NOx per Joule of heat output.


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