Service manual

6
3:1 THE ELECTRICAL HEATING CARTRIDGE
DOES NOT WORK
Cause:
- Check that the changeover switches on the control panel
are in the correct positions (see operating instruction for
boiler).
- The 12 V fuse has blown.
- No or low voltage to the boiler. (< 12 V).
- 230 volt not connected.
- The overheating protection device has been triggered.
- The thermostat is broken/damaged
- Damaged printed circuit board.
- Damaged electrical heating cartridge.
- Faulty wiring or wire connections.
Action:
During faultnding, the hot water switch must be in the
ON position and the power plug switched to 2 or 3 kW
on the control panel.
- Check that the 12 V fuse (see g. 1 A) is intact.
- Measure the input voltage. It must be no lower than
10.8 V.
- Check that the 230-volt cable is connected and that the
vehicle is connected to a 230-volt outlet.
- Check that the overheating protection device has not
tripped. If necessary, reset by rst unscrewing the black
protective cap, then pressing down the reset button (see
g. 1 B). When the overheating protection device has
been reset, there must be a 12-volt input on one at-pin
terminal and 12-volt output on the other (see g. 2 A),
otherwise it is defective and must be replaced.
N.B! If the overheating protection device has tripped
it cannot be reset until the boiler has cooled 10-20°C.
Before the boiler is restarted, check that it has been bled
thoroughly.
- Check that the operating thermostat is turned to the
maximum clockwise position (see g. 1 C).
- Check that there is voltage (12 V) on at-pin terminal
12 (grey cable, low temperature) and terminal 22 (blue
cable, high temperature), see g. 2. If there is no voltage
on terminals 12 and 22, but there is voltage on terminal
11 (red cable), the operating thermostat must be repla-
ced.
- Check that there is voltage on pos. 9 on the P1 printed
circuit board (see g. 3). If not, the printed circuit board
must be replaced.
- Check that there is voltage on pos. 12 and 15 on the P1
printed circuit board (see g. 3). If not, there is a fault in
the wiring or on the control panel.
- Check the resistance of the electrical heating cartridge
(approx. 50 ohm for 1 kW, and 25 ohm for 2 kW) and the
insulation to earth (> 1 Mohm). In the event of a fault,
replace the cartridge.
- Check that the wiring connections are intact and correctly
tted.
- If none of the above measures solves the problem,
replace the printed circuit board. The fault will lie in the
control relays for 12/230 volts.
3:0 FAULTFINDING
A
B
C
A
Grey 12
Blue 22
9
15
12
Red 11Red
BE AWARE OF THE RISKS OF 230 V DURING ALL SERVICE WORK
Fig 1.
Fig 2.
Fig 3.