IDEAL isar HE24 User Manual

59
FAULT FINDING
FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING FAULT FINDING
isar - Installation and Servicing
90 H.....2..... (CONTROL THERMISTOR [RETURN] ERROR)
YES
Is there continuity between the
PCB and the thermistor ?
Remove the boiler return thermistor from the
CH return pipe.
Are the thermistor values correct ?
Replace the thermistor
NO
NO
YES
Replace PCB
Check and replace wiring as necessary
91 H.....3..... (DHW THERMISTOR ERROR)
YES
Is there continuity between the
PCB and the thermistor ?
Remove the boiler DHW thermistor from the plate
heat exchanger and disconnect thermistor wires.
Are the thermistor values correct ?
Replace the thermistor
NO
NO
YES
Replace PCB
Check and replace wiring as necessary
Check resistance using a suitable multimeter
connected across the thermistor’s terminal pins
At 25
o
C expect 9,700 - 10,300 Ohms
At 60
o
C expect 2,400 - 2,600 Ohms
At 85
o
C expect 1,000 - 1,100 Ohms
Check resistance using a suitable multimeter
connected across the thermistor’s terminal pins
At 25
o
C expect 9,700 - 10,300 Ohms
At 60
o
C expect 2,400 - 2,600 Ohms
At 85
o
C expect 1,000 - 1,100 Ohms
203319-3.pmd 27/03/2008, 08:1559

IDEAL isar HE24 Specifications

General

Boiler Type	Combi
Central Heating Output	24kW
DHW Flow Rate	9.8 l/min
Mounting	Wall Mounted
Domestic Hot Water Output	24 kW
ERP Rating	A
Output	24 kW
Central Heating Flow Temperature Range	30-80°C
Dimensions	700 x 395 x 278 mm
Warranty	2 Years
Fuel Type	Natural Gas
Efficiency Rating	A Rated