ICI Caldaie RIO 140, Installation And Servicing Manual

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9 REPLACEMENT OF COMPONENTS
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9.21 AUTOMATIC AIR VENT
The air vent is positioned at the back of the boiler on the upper left hand side and is accessible without
opening the case.
1 Ensure that the electricity supply has been isolated.
2 Drain the central heating circuit of the boiler as described in section 8.
3 Unscrew the automatic air vent from the fitting and replace with a new one using a new 'O' ring.
Check that the small cap in the top of the air vent is screwed in fully, then unscrew it one complete turn -
the cap remains in this position from now on.
4 Fill the boiler and re-pressurise the system to between 0.8 and 1.5 bar (to match the original system
pressure) as described in section 4.2, paragraphs 2 to 7.
5 Test the boiler as described in section 7.5, paragraphs 1,2 and 3.
9.22 CENTRAL HEATING EXPANSION VESSEL (red)
The expansion vessel is positioned on the back of the boiler and is accessible from the top.
1 Ensure that the electricity supply has been isolated.
2 If rear exit flue is used, disconnect the flue elbow from the flue and remove it from the top of the boiler.
3 Drain the central heating circuit of the boiler as described in section 8.
4 Remove the one screw (L/H side) securing the expansion vessel retaining channel and withdraw the
channel.
5 Undo the union at the bottom of the vessel and remove by lifting the vessel up and out of the boiler.
6 Re-assemble in reverse order, using a new sealing washer on the expansion vessel connection. The
bottom connection of the expansion vessel should be towards the front of the boiler when fitting it.
Note: Ensure the expansion vessel is correctly located in the bottom fitting and that it is secured by the
fixing channel.
7 Fill the boiler and re-pressurise the system to between 0.8 and 1.5 bar (to match the original system
pressure) as described in section 4.2, paragraphs 2 to 7.
8 Test the boiler as described in section 7.5, paragraphs 1,2 and 3.
9.23 HOT WATER EXPANSION VESSELS (4 litre - white, 2 litre - silver)
The boiler is fitted with two hot water expansion vessels, see Fig. 19. The 4 litre expansion vessel is
positioned on the back of the boiler at the right hand side and is accessible from the top. The 2 litre vessel is
positioned behind the upper front panel.
1 Ensure that the electricity supply has been isolated.
2 Drain the hot water circuit of the boiler as described in section 8.
3 4 litre vessel - Remove the one screw (L/H side) securing the central heating expansion vessel retaining
channel and withdraw the channel.
Undo the union at the bottom of the vessel, remove the two screws at the top securing the vessel to the
mounting bracket and remove by lifting the vessel up and out of the boiler.
4 2 litre vessel - Undo the union at the bottom of the vessel, remove the screws securing the locating
bracket and remove the vessel.
5 Re-assemble in reverse order, using a new sealing washer on the expansion vessel connection.
6 Open the mains water supply valve to refill the storage tank and vent the circuit by opening the hot taps.
7 Test the boiler as described in section 7.5, paragraphs 1,2 and 3.
9.24 PRIMARY WATER FLOW SWITCH
The primary water flow switch assembly is positioned above the pumps.
The microswitch can be replaced without draining the boiler.
Microswitch
1 Ensure that the electricity supply has been isolated.
2 Open the upper front panel (hinges to the left) to gain access.
3 Remove the plastic cover from the primary water flow switch and slide the microswitch from its housing
pins.
Disconnect the electrical leads and connect to the new switch (polarity is not important, but use only the
two outer terminals).
4 Carefully move the operating lever away to allow the microswitch to locate on its housing pins.
5 Re-assemble in reverse order and test the boiler as described in section 7.5, paragraphs 1,2 and 3.