Water Heater Water Heater Submittal

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TRGSS00121
Residential / Commercial Gas
Tankless Water Heaters
SUGGESTED SPECIFICATION FOR TK-540X3-NIH OR TK-540X3-NEH
The fully modulating, on-demand, condensing gas fired tankless water heater(s) shall be Takagi Tankless Water Heater model
TK-540X3-NIH or TK-540X3-NEH, having a maximum input rating of 199,000 Btu/h and available in NG or LP. The heater
shall have ¾ in. male NPT water and gas connections. The inlet gas supply pressures shall be 4.0 in. WC (min.) up to 10.5 in.
WC (max.) for NG and 8.0 in. WC (min.) up to 14 in. WC (max.) for LP. The water heater shall have the integrated X3 Scale
Prevention Technology to prevent scaling of the heat exchangers. The indoor heater(s) shall incorporate an integrated temperature
controller that will provide diagnostic information, fault history, and heater set temperature. The outdoor heater shall be factory
supplied with a temperature remote, 100209924, that can be installed up to 400 ft. from the heater using 20 gauge (minimum)
control wire. The temperature remote shall provide diagnostic information, fault history, and heater set temperature. The heater shall
operate using 120 V / 60 Hz power source. The indoor heater will incorporate a factory installed power cord.
The indoor heater shall be vented with 3” or 4” diameter schedule 40 PVC (solid core), CPVC, ABS, polypropylene or category IV
vent pipe with a length not to exceed 70 ft. (equivalent) for 3” vent or 100 ft. (equivalent) for 4” vent, terminating horizontally or
vertically. The intake pipe may use material such as PVC, CPVC, ABS, aluminum, or Category IV pipe and cannot exceed 70 ft.
(equivalent) for 3” vent or 100 ft. (equivalent) for 4” vent.
The water heater shall use a commercial grade copper alloy, fin tube primary heat exchanger with quick release brass or bronze
waterways. The secondary heat exchanger shall be constructed from stainless steel 316L. The heater shall be controlled by an
onboard solid-state printed circuit board which uses the following factory installed components: thermistors to monitor inlet & outlet
water temperature and exhaust temperature; a flow sensor to measure flow rate; a flame sensor to monitor combustion; an air-fuel
ratio rod to measure and adjust operation in order to maintain optimal combustion efficiency. The heater also consists of inline
fusing and surge absorbers for electrical surge protection, an electronic spark igniter, aluminized stainless steel burners, hi-limit
temperature switches to monitor water and exhaust temperatures, modulating gas valve, an overheat cutoff fuse, ceramic heating
blocks to protect the heat exchanger and water piping. The indoor heater shall incorporate auto-fire system for additional freeze
protection. The indoor model shall include an exhaust temperature monitoring system using an exhaust thermistor and automatic
hi-limit switch to maintain safe exhaust temperatures for sch. 40 PVC. The heater shall have a built-in condensate trap for the
secondary heat exchanger The heater shall incorporate a condensate drain blockage detector to provide safe operations and
prevent overflow.
The heater shall be design certified by CSA according to CSA/ANSI Z21.10.3•CSA 4.3, approved for sale in the United
States, ENERGY STAR
®
qualified, has a minimum uniform energy factor of 0.93, meets the energy efficiency requirements of the
U. S. Department of Energy and ASHRAE 90.1, complies with SCAQMD Rule 1146.2 and other air quality districts with similar
requirements for low NOx emissions of 14 ng/J or 20 ppm.