Takagi T-H3J-DV Service Handbook page 50

Outdoor Model (Front View/Cabinet Interior):
NOTE: 540 outdoor models include a heat exchanger thermistor and a
bypass valve which are not shown in this graphic. However, their locations
are shown in the graphic for indoor models (page 49).
Figure 42 .
High Limit Switch
(Heat Exchanger)
Over-heat
Cutoff Fuse
(OHCF)
Connector for
Overheat Cutoff
Fuse (Blue Wires)
Fuse Box
Flame Rod
& AFR* Wire
Connections
This Screw
Secures the
Computer
Board
Assembly.
Computer
Board (PCB)
Outlet
Ground
Thermistor
Connection
(behind PCB)
* Air/Fuel Ratio Rod
See also "Component Diagrams/Item Numbers" which starts on page 71.
50 • On-Demand Water Heater Service Handbook for 240, 340 & 540 Condensing Models
Exhaust Vent
Screws (2)
Securing
Fuse Box
Flow Sensor/Control
Valve (Behind Wires)
Pipe Heater
Condensate
Drain Tube
Clear Plastic Tube
(Combustion Chamber Tube)
Inlet Thermistor (black wires)
Three Screws
Secure the Secondary Heat
Exchanger to the Case
Secondary Heat
Exchanger
Primary Heat
Exchanger
Igniter Rod Wire
Connection
Burner
Igniter Assembly
(not visible)
Manifold Plate
Brass Manifold
Test Port Screw
Main Gas Valve
Gas Proportional
Valve (GPV)
Brass Screw Securing
Gas Valve to Gas
Inlet Connection.