20
Super Plus -
Installation and Servicing
Resecure the pressure switch lead and fan motor lead, to the clips
in the control chassis. Ensure all connections are tight.
Refit the overheat thermostat coil into its pocket on the flow header
and secure with the retaining strip and split pin. Refit the control
thermostat sensor into the pocket in the return elbow and push it
fully home, securing it with the retaining clip. Replace the module
multipin electrical plug.
MODULE CLEANING INSTRUCTIONS
If the inspection of the dry side of the heat exchanger has shown
that a thorough cleaning is required, it is necessary to remove the
module from the boiler.
Preparing the Boiler
1.
Undo the retaining screw from the front of the module upper
cover and remove it by pulling forwards and lifting slightly at
the back to clear the shoulder nuts,
2
. Pull out the multipin electrical plug from the side of the module.
3.
Undo the screw at the base of the controls box and remove the
lower cover by lifting it to clear the shoulder nuts and pulling it
forwards.
4.
Isolate the boiler from the flow and return water pipes and drain
the boiler.
5.
Remove the fan and controls box assembly, venturi casting and
burner, as described under Servicing. Uncouple the flanges
connecting the modules to the flow and return water headers.
6.
It may be necessary to remove the flow and return elbows from
the module front plate to release the flange gaskets. The elbows
should then be replaced for lifting purposes, after ensuring that
the gaskets between the elbows and the front plate are sound.
7.
Isolate the electrical supply to the boiler and remove from the
wiring centre the appropriate fuse controlling the module, to
ensure that the module multipin plug is electrically isolated.
8.
Remove the 4 screws securing the module gas inlet flange.
Slacken the union nut on the module gas cock. Undo the 4
nuts securing the module to the boiler. Withdraw the module
to be cleaned from the boiler.
9.
Take care as the module will not be completely empty of water.
10.
In order to provide continual support for the water flow and
return headers and the gas header, it is advisable to remove
only one module at a time from the boiler.
11
. Undo the 3 screws holding the gas distribution screen round
the finned tubes and remove it.
12.
The finned tubes can now be thoroughly brushed clean from
both inside and out, using a suitable brush.
13.
Re-assemble the gas distribution screen, ensuring that the
slots in the screen are in line with the outermost point of the
finned tubes.
14
. Re-assemble the module to the casing and refit the water and
gas flanges.
15.
Refit the burner venturi casting, fan and controls box assembly,
as described under 'Servicing'. All damaged gaskets must be
replaced.
16.
Retighten the module gas cock union.
17.
Repeat the cleaning procedure for other modules as necessary.
MODULE WATERWAYS
The procedure below details the method of draining down the boiler,
removing a module and dismantling for inspection of the waterways.
1.
Remove the module from the boiler, as previously described
and remove all fittings from the module cast iron top plate.
2.
Remove the 16 x M10 screws and the 9 central M8 screws
which secure the cast iron top plate to the aluminium top tube
plate and lift the top plate off.
3.
The waterways can now be examined.
If the tubes are scaled or partially blocked then the module must be
cleaned, either by replacing the module into the boiler and cleaning
all the modules at the same time, or individually.
Note:
the heat exchanger is of aluminium and so any chemical
descaling must be suitable for aluminium. Advice on the procedure
for descaling the waterways can be obtained from specialists such
as Fernox, Fry Technology UK, Tandem House, Marlowe Way,
Beddington Farm Road, Croydon. CRO 4XS, tel. 0870 5601 5000
- or - Betz Dearborn Ltd., Sentinel Division, Foundry Lane, Widnes,
Cheshire WA8 8UD, tel. (0151) 424 5351
Re-assembly
1. New gaskets should be used between mating flanges. The
gaskets should be lightly greased before use.
2.
Tighten the central 9 x M8 screws evenly to a torque of 24.4
to 27 N/m (18 to 20 ft Ib). This maximum torque must not be
exceeded.
3.
Tighten the 16 outer M10 screws evenly to a torque of 48.8
to 54 N/m (36 - 40 ft Ib). This maximum torque must not be
exceeded.
4.
Reassemble the boiler as previously described.
UPON COMPLETION OF A SERVICE
OPERATION:
RE-COMMISSlON AND TEST THE BOILER IN ACCORDANCE
WITH THE COMMISSIONING AND TESTING INSTRUCTIONS
WITH PARTICULAR REFERENCE TO THE FAN PERFORMANCE
CHECKS.
REPLACEMENT OF COMPONENTS
WARNING:
Before working on the appliance:
1.
Isolate the boiler electrical supply.
2.
Turn off the gas supply at the inlet gas cock.
Note:
To replace the following components first undo the retaining
screw from the front of the module upper cover. Remove the
cover by pulling forwards and lifting slightly at the back to clear
the shoulder nuts.
Pull out the multi-pin electrical plug from the side of the module.
Undo the screw at the base of the controls chassis and remove
the lower cover by lifting it to clear the shoulder nuts and pulling
it forwards.
Sight Glass
1
. Undo the 2 screws securing the sight glass assembly to the
front header casing.
2.
Fit the replacement sightglass, ensuring the parts are in the
correct order, i.e. gasket, glass, gasket and frame.
3.
Retighten the 2 screws to ensure an airtight seal.
DO NOT OVERTIGHTEN.
Control Thermostat Sensing Probe
1.
Pull out the overheat thermostat coil, retaining clip and split pin
from its pocket in the flow elbow. Undo the 2 screws securing
the 2 halves of the control box and carefully lower the front half.
2.
Pull out the control thermostat sensing probe and retaining clip
from its pocket in the return elbow and undo the strain relief
bush from the controls box back panel.
3.
Unplug the lead from the printed circuit board 9B, inside the
controls box, and remove the sensing probe.
4.
Carefully fit the new probe; note that the plug will only fit its
correct socket.
5.
Refit the strain relief bush, ensuring that the probe is pushed
fully home in its thermostat pocket. Retain it with its retaining
clip.
6.
Refit the overheat thermostat coil to its pocket in the flow elbow
and secure with its retaining strip and split pin.
SER
VICING
SERVICING
