Gas Tankless Water Heaters
RESIDENTIAL MODELS
Tankless Non-Condensing Models
Fully modulating, gas fired, tankless water heater specifically
designed for residential applications. Supplies hot water to
domestic hot water systems (directly or indirectly) which
can be used with storage tanks, recirculation systems,
hydronic heating systems, radiant floor heating systems,
and/or combined domestic and heating applications.
Features
Designed for Performance
• Maximum flow rates up to 10.0 GPM
• Available in natural gas (NG) or propane (LP)
• Models include both a remote control and power cord as standard features
• Low NOx emissions
• Complies with lead free standards
• Heat exchanger (510 model) is constructed of commercial-grade copper
• Built-in freeze protection
• Easy-Link up to 4 units with no additional parts or accessories needed (510 models only)
• Air-fuel ratio (AFR) sensor
• Electronic ignition
Safety features
• Manual reset hi limit (set at 194°F)
• Overheat cutoff fuse
• Inlet and outlet thermistors for constant temperature
monitoring
• Flame sensor
JWT-110, JWT-310, JWT-510
ANSI Z21.10.3
WARRANTY
15-year limited warranty on heat exchanger in
residential applications
5-year limited warranty on heat exchanger in
commercial applications
5-year limited warranty on all parts
Consult installation manual for terms and conditions or visit
www.johnwoodwaterheaters.com for more information.
Gas Tankless Water Heaters
RESIDENTIAL MODELS
FLOWRATE
RATEvsvsTEMPERATURE
TEMPERATURERISE
RISE
FLOW
*Maximum flow rate with set temperature above 131°F (55°C) is 8.0 GPM.
PRESSURELOSS
LOSSvsvsFLOW
FLOWRATE
RATE
PRESSURE
Gas Tankless Water Heaters
RESIDENTIAL MODELS
Optional Accessories
Part Number
Description
100074536
Direct vent conversion kits
100112156
Isolation valve kits
100078178
Backflow preventer
100066818
Concentric direct vent kit
100112188
Pipe cover for 110 models
100112187
Pipe cover for 310/510 models
SUGGESTED SPECIFICATION
Water heater(s) shall be the fully modulating, non-condensing gas fired John Wood tankless water heater model ___________, having a
maximum input rating of ____________ BTU/h. The heater shall have ¾” male NPT water and gas connections. The inlet gas supply pressures shall be _____ in. WC (minimum) up to _____ in. WC (maximum) for _____ fuel. The heater shall incorporate an integrated temperature
controller that will provide diagnostic information, fault history, and heater set temperature. The heater shall operate using 120V/60Hz power and
will incorporate a factory-installed power cord.
The water heater(s) shall be direct vented with 3”/5” APNC35 concentric vent with a length not to exceed 43 equivalent feet, terminating
horizontally or vertically with no more than four (4) 90° elbows.
The water heater(s) shall use a commercial grade copper alloy, fin tube primary heat exchanger with quick release brass or bronze waterways. The
heater(s) shall be controlled by an onboard solid-state printed circuit board which uses thermistors to monitor inlet and outlet water temperature
and exhaust temperature, a flow sensor to measure flow rate, a flame sensor to monitor combustion, and an air-fuel ratio rod to measure and
adjust operation in order to maintain optimal combustion efficiency. The heater(s) shall also consist of inline fusing and surge absorbers for
electrical surge protection, an electronic spark igniter, aluminized stainless steel burners, hi-limit temperature switch to monitor water temperature,
modulating gas valve, an overheat cutoff fuse, and incorporate ceramic heating blocks and an auto-fire system for freeze protection of the heat
exchanger and water piping.
The water heater(s) shall be design certified by CSA according to ANSI Z21.10.3 *CSA 4.3 and meet the energy efficiency requirements of
NRCan and the current edition of ASHRAE 90.1.
Gas Tankless Water Heaters
RESIDENTIAL MODELS
SPECIFICATIONS
GAS CONSUMPTION
INLET GAS PRESSURE
MODEL
FUEL
INPUT
NUMBER
TYPE
MINIMUM MAXIMUM
BTU/h
MINIMUM
MAXIMUM
IN. W.C.
IN. W.C.
BTU/h
ENERGY
FACTOR
(EF)
DIMENSIONS
MAXIMUM
GPM*
HOT/COLD
UNIT
IN (CM)
GAS
CONNECTIONS CONNECTION
WEIGHT
HEIGHT
WIDTH
DEPTH
LB (KG)
JWT-110-N
Natural
19,500
140,000
5.0
10.5
0.82
6.6
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
7 ¾ (20)
33 (15)
JWT-110-P
Propane
19,500
140,000
8.0
14.0
0.83
6.6
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
7 ¾ (20)
33 (15)
JWT-310-N
Natural
11,000
190,000
5.0
10.5
0.82
8
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
9 ½ (24)
38 (17)
JWT-310-P
Propane
11,000
190,000
8.0
14.0
0.82
8
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
9 ½ (24)
38 (17)
JWT-510-N
Natural
11,000
199,000
5.0
10.5
0.83
10
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
9 ½ (24)
39 (18)
JWT-510-P
Propane
11,000
199,000
8.0
14.0
0.82
10
¾” NPT
¾” NPT
20 ¼ (52)
13 ¾ (35)
9 ½ (24)
39 (18)
15-150 PSI water pressure. 40 PSI or above recommended for maximum flow.
*Current numbers based on factory testing, 0.5 GPM required for activation, 0.4 GPM required for continuous fire after initial ignition.
Models are certified from sea level to 6,000 ft. (1,829 m) elevation.
JWT-110 DIMENSIONS
MINIMUM CLEARANCES: TOP 12”, BOTTOM 12”, FRONT* 4”, BACK 1”, SIDES 3”
4" (101 mm)
1-3/4" (45mm)
4" (102mm)
1-3/4" (45mm)
2-1/4" (57mm)
13-3/4" (350mm)
10" (254mm)
20-1/4" (520mm)
21-3/8" (544mm)
2-1/4" (56mm)
1-7/8" (47mm)
COLD 3-1/8" (79mm)
HOT 5-1/4" (133mm)
1" (26mm)
2-1/4" (56 mm) COLD
3-7/8" (98mm) GAS
4-7/8" (123mm) 120V
4-7/8" (124mm) HOT
7-3/4" (196mm)
120V 1-3/8" (36mm)
GAS 4-7/8" (124mm)
JWT-310 AND JWT-510 DIMENSIONS
MINIMUM CLEARANCES: TOP 12”, BOTTOM 12”, FRONT* 4”, BACK 1”, SIDES 3”
4" (101 mm)
4-3/8" (113mm)
1-3/4" (45mm)
19-3/8" (493mm)
20-1/4" (520mm)
21-3/8" (544mm)
1-3/8" (36mm)
1-7/8" (47mm)
COLD 3-1/4" (84mm)
120V 1-3/8" (36mm)
HOT 5-1/4" (133mm)
GAS 4-7/8" (124mm)
1-5/8" (43mm)
13-3/4" (350mm)
10" (254mm)
1-3/4" (45mm)
1" (26mm)
COLD 2-7/8" (71mm)
120VAC 3-7/8" (99mm)
GAS 5-1/4" (135mm)
HOT 6-1/2" (164mm)
9-1/2" (241mm)
*Recommended 24” clearance from front of unit for maintenance
© 2017 Printed in Canada
JWT45201 (10-17)
For Technical Information/Warranty:
Call 1-888-479-8324 or email techsupport@johnwoodwaterheaters.com
www.johnwoodwaterheaters.com