Service
Manual
Page
Edition
Type 34. Inlet Valve, Water
Repair instruction
Valve operation gradually gets worse
Hot water with high lime content cause scale
deposits in the balancing nozzle of the valve. Clean
the nozzle as follows:
• Shut off the water.
• Unscrew the nozzle and clean it with a needle or
similar. A nozzle marked with one ring around
the head of the screw has a bore diameter of 0.5
mm and a nozzle with two rings has a bore
diameter of 0.8 mm. The diameter of the needle
used to clean the nozzle must not be greater
than the bore diameter.
• Re-fit the nozzle.
• Turn on the water, check operation and check
for leaks.
• If this does not help, check that the inlet filter of
the pilot channel is not blocked.
Where the water is very hard, i.e. contains a high
lime content, it is recommended that the 0.5 mm
nozzle should be replaced with a 0.8 mm nozzle.
Valve does not open
• Check for voltage at coil.
• Measure the resistance of the coil to check for
short circuit or open circuit.
• Dismantle the valve and check that the armature
is not binding. If necessary, clean to remove
scale, particularly in the ducts of the valve
between the top and bottom of the diaphragm.
• Remove the coil and clean the metal surfaces of
the magnet core.
Valve does not close
• Check that there is no voltage across the coil.
Normally the valve is closed when the coil is de-
energised.
• Dismantle the valve and check the armature
return spring and check that the armature is not
binding. If necessary, remove limescale deposit,
particularly in the ducts of the valve between the
top and bottom of the diaphragm.
• Check the balancing nozzle in accordance with
the instructions under the heading "Valve
function gradually gets worse".
1365
34 8911
32
0369
Needle
Balancing nozzle