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”
10
Anti-Frost Heater Circuit
Models with an ‘F’ in the model number have an anti frost heater circuit e.g. 871024NF-B.
The anti-frost heaters are wired in series and operate independently from the water heater.
The 24 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 59 for
replacement procedure.
Product Changes
Software Changes
Models manufactured after May 2006 have a change to the software which controls the
operation of the heater. When an inlet water temperature of more than 58ºC and more
than the set point temperature minus 2ºC is detected by the inlet water temperature
thermistor, the fan and burner will not operate.
This function has been introduced to enhance the operation of the water heater and
remove the need for a Solar Bypass Valve when the Integrity 24 is connected as an in-
series gas booster to a solar water heating system (for more information refer to ‘In-series
Gas Boosting’ on page 15).
Models with the revised software have a -C suffix added to the model number i.e.
871024NF-C.
Parts Replacement & Wiring Changes for 871024, 871024-B & 875024-B Model
Heaters Only
Some parts for 871024, 871024-B & 875024-B model heaters have been superseded and
are no longer available (refer to following tables). If any of these superseded parts are
found to be faulty they must be replaced with current parts available for 871024-C and
875024-C model heaters.
Some current parts utilise different wiring connectors/connections necessitating the
replacement of other interconnecting components when installed in 871024, 871024-B and
875024-B model heaters (refer to ‘Parts Replacement Scenarios’ on page 11). Part
numbers shown in the following tables which are not marked with an asterisk (*) can be
considered a direct replacement and require no additional components or modifications
when installed in 871024, 871024-B and 875024-B model heaters.
Note: The parts lists shown on pages 64 - 75 are for current 871024-C and 875024-C
model heaters; superseded part numbers for 871024, 871024-B and 875024-B model
heaters are not shown therein however they are listed in the following tables.