Specifications

TM031 Integrity 24L Service Instructions REV: A
D.O.I: 30/10/2007
This document is stored and maintained electronically by Service. All printed copies not bearing this statement in RED are deemed “uncontrolled”
9
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 (Models with F in model
number only e.g. 871024NF)
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 valve fitted to the water body assembly controls the bypass. Two types of bypass
valve are utilised in the 24 litre Integrity.
Mechanical Bypass
Models without a -B or -C suffix in the model number utilise a mechanical bypass e.g.
871024NF. The mechanical bypass is a small spring loaded valve located in the water
body assembly. The spring is temperature sensitive, as the cold water temperature
decreases the spring tension increases reducing the amount of cold water flowing through
the bypass. The bypass operates at all times when water is flowing.
Solenoid Operated Bypass
Models with a -B or -C suffix in the model number utilise a solenoid operated bypass e.g.
871024NF-B. The solenoid operated bypass comprises a valve (located in the water body
assembly) that is controlled by a solenoid (mounted on the water body assembly). 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.