Specifications

TM023 Integrity 26L Service Instructions REV: B
D.O.I: 17/10/2007
This document is stored and maintained electronically by Service. All printed copies not bearing this statement in RED are deemed “uncontrolled”
7
Sequence of Operation Component Diagram
1 Hot Water Tap
2 Bypass Control Valve
3 Water Flow Sensor
4 Inlet Water Temperature Thermistor
5 Combustion Chamber Thermistor
6 Outlet Water Temperature Thermistor
7 Water Flow Servo Motor
8 Water Filter (Strainer)
9 Gas Inlet Solenoid Valve
10 Gas Solenoid Valve 1
11 Gas Solenoid Valve 2
12 Gas Solenoid Valve 3
13 PGFR Valve
14 Nozzle
15 Burner
16 Igniter
17 Igniter Electrode
18 Flame Sensor
19 Heat Exchanger
20 Over Temperature Limiter
21 Exhaust (Flue) Outlet
22 Combustion Chamber
23 Anti Frost Heater
24 Fan
25 Fan Motor
26 Drain Plug With Relief Valve.
27 PCB
Bypass Operation
The bypass is a section of copper pipe work connected between the water body assembly
(effectively the cold water inlet) and the outlet of the heat exchanger and allows a quantity
of cold water to bypass the heat exchanger. The purpose of the bypass is to ensure the
heat exchanger operates at temperatures above the dew point of the combustion gases,
ensuring condensate is not produced, but low enough to maximise the heat exchangers
life. A solenoid valve fitted to the water body assembly controls the bypass. The PCB
activates the solenoid at the following predetermined temperatures:
Without Touch Pads: When the unit is preset at 40 or 43 degrees.
With Touch Pads: When temperatures from 37 to 46 degrees are selected.
At all other times the bypass does not operate.
Anti-Frost Heater Circuit
The anti-frost heaters are wired in series and operate independently from the water heater.
The 26 litre models have an 82-watt anti-frost system.
A thermostat sensing ambient air temperature, positioned in the wiring loom near the
bottom of the water heater, activates the anti-frost heaters when the ambient air
temperature falls to 4ºC +4ºC/-2ºC and deactivates the anti-frost heaters when the
temperature rises above 12ºC.
In the event a heater block becomes open circuit the total heater circuit is rendered
inoperable. The total heater circuit measures 702.6 ohms.
The circuit is split into two sections with 4 heaters in total. To determine which section has
failed, isolate the power to the water heater and unplug the wiring connectors at the
thermostat, cord set and the water body assembly heater block. The heat exchanger and
hot water outlet heater’s resistance (3 heater blocks) is 565.5 ohms. The resistance of the
water body assembly heater is 137.1 ohms. Refer to Procedure 10 on page 56 for
replacement procedure.