Page 5 The Mattress Variator Manual
for signs of heat damage to the solenoid, pump casing and air switches. If there is any signs of damage to
the parts or wiring the parts or wiring must be replaced. As an additional check a normal solenoid has 0.9
to 1K resistance across it's terminals and the motor about 10 to 30 Ohm resistance. The air switches are
detailed on their sides for their switching pattern, this can be checked with a multimeter. The fuse should
only be replaced by one of the same type. The fuse fitted to this unit is a 5 Amp, 250 V, ceramic antisurge
(T) type.
F. Is the fuse in the plug OK?
G. The fuse in the plug is intended to blow if the Mains Lead is damaged. If this fuse has blown check the
mains lead for damage before replacing the fuse. If there is any damage to the mains lead it should be
replaced. To replace the Mains lead it will be necessary to remove the lid of the machine, this is done by
removing the six screws in the upper case. Remove the mains lead connections from the fuse holder and
mains switch. Undo the two screws holding the mains lead at the back panel, cut the terminals from the
end of the mains lead and pull the mains lead from the unit. Refitting is the reverse of removal ensuring
the new terminals are fitted after the lead is pushed through the hole, and the blue wire is fitted to the
switch and the brown to the fuse holder.
H. If the Unit is switched on and the light in the switch does not come on the fuses should be checked first.
Then the Mains Lead should be tested with a continuity meter, (including the brown wire from the fuse
holder to the mains switch), if a fault is found it should be replaced as above (2). If no fault is found the
mains switch should be replaced. This is done by squeezing the switch top and bottom inside the unit, then
pushing it out of the control unit. Ensure the wires are replaced in the same places they are removed.
I. With the control unit switched off, press each button on the handset and listen for the quiet click
produced inside the control unit by the handset.
J. Check which type of handset you have first. There are 4 types. 1) Green and white push buttons with
integral twin tubing, 2) Yellow or grey large circular buttons without integral twin tubing, 3) Blue or
Yellow topped lever style without integral twin tubing. 4) Black with grey push buttons that are able to
rotate. Type 1 & 4 handsets disconnect from the control unit at the front panel and replacements are
supplied with twin tubing. Type 2 & 3 handsets disconnect at the handset end and replacements are not
supplied with twin tubing. The different types of handset are interchangeable. To change a type 1 handset,
carefully pull the tubes from the barbs in the front panel, and reconnect the new handset. To change a type
2 or 3 handset, pull the tubing from the handset and reconnect the new handset. Both types of handset will
require testing to check that the connections are the correct way round.
K. If the Control unit does not work after the handset has been changed, replace the air switch.
L. To change an Air Switch it is necessary to remove the lid of the equipment. CAUTION this equipment
is mains powered and should be isolated from the mains before it is opened. To remove the lid undo the 6
(six) screws in the upper case, (2 in each side and back), squeeze the sides of the lid inward to release the
lid from the handle moulding. The air switches are mounted on the inside of the front panel. The "up" air
switch has only 2 (two) wires while the down air switch has 3 (three) wires. Pull each wire from the switch
to be changed and attach it to the new switch in the corresponding position, then unscrew the old switch
from the front panel and attach the new one. Refit the lid before testing the unit.
M. Test the unit operates correctly now the new switch has been fitted. If it does not the wiring should be
checked.
N. To check that the wiring is in place it will be necessary to remove the lid of the equipment. CAUTION
this equipment is mains powered and should be isolated from the mains before it is opened. To remove the
