Installing The Boiler; Method Of Positioning The Boiler On Th Wall; Connecting The Boiler To The System; Safety Valve And Condensats Drains - Benchmark Calydra green 24 Nat Installation And Operating Instructions Manual

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Installing the Boiler

Please check that you are familiar with the installation requirements before commencing work (section 6).
The installation accessories described in the following list are included in the boiler packaging.
- Hanging bracket
- A paper template (showing the dimensions of the boiler with 5 mm side clearances, fitting instructions and commissioning
instructions)
- Connection tails
- Screws and wall plugs
- Connection washers and filters
- Installation manual
Method of positioning the boiler on the wall.
The paper template can be used to ensure the correct positioning of kitchen cabinets etc. It also details the commissioning
instructions.
The paper template has to be fixed to the wall and used to locate the position of the hanging bracket and the centre for the flue
hole.
Drill and plug the wall and secure the hanging bracket using the screws provided. Remove the boiler from its packaging as
shown (Fig. 8) and unscrew the 4 screws A and remove the casing (Fig. 9).
Place the boiler on the wall on the hanging bracket (Fig. 11).
If required, there is space for all piping to pass behind the boiler. Using (Fig. 11) for reference, connect the gas and water
pipes and the valves to the base of the appliance using the tails provided. There is a 190 mm space between the valves and
the wall to make these connections.

Connecting the boiler to the system

- Push in the tabs "P" (Fig. 13) on either side of the boiler and pivot the electrical box forward to gain access to the valve
connections
- Remove the yellow caps and connect the boiler to the taps using the washers provided in the plastic bag.
4 x fibre washers for the C.H. flow and return, hot water outlet and cold water inlet connections
1 x rubber washer "R" for gas connection.
Provision must be made to fill and recharge the system pressure. This can be achieved using a filling loop or other methods
approved by the local water authority.
Before fitting the tails onto the connecting bracket, please check the correct location of the flow restrictor L (Fig.10) on the
main inlet.
Safety valve and condensate drains
The pressure relief valve tube is clear silicone. It should terminate below the boiler over a tundish or 22 mm pipe (see I Fig. 4)
which should in turn discharge safely outside the premises. Care should be taken that it does not terminate over an entrance
or window or where a discharge of heated water could endanger occupants or passers by.
External termination via condensate siphon
The condensate drainage pipe should have a minimum diameter of 22 mm and the external pipe length should not be more
than 3m. The external length should be kept as short as possible to minimize the effect of freezing.
Please refer to BS 6798 : 2000
The system should be carefully checked for leaks, as frequent refilling could cause premature system corrosion or
unnecessary scaling of the heat exchanger. The pipe from the siphon 12 (fig. 1) should be connected to a drain in the
conditions described in the relevant Brittish regulations.
Pay special attention to not bend the condensates silicone drain pipe in such a way as to cause the flow to be interrupted.
Please use only drain pipe material compatible with condensate products. (refer to BS 6798 : 2000)
The condensate flow can reach 2 litres/hour; because of the acidity of the condensate products (Ph close to 2), take care
before operation.

Fitting the Horizontal Flue

Important!! Before starting the boiler, the siphon 12 (Fig. 1) must be filled with water. Before fitting the flue terminal
onto the boiler, please pour 1/4 litre of water in the exhaust pipe as shown (Fig. 12).
The instructions for the vertical and biflux (twin pipe) flue options are included with the relevant adapter kits.
The standard flue supplied with the appliance is suitable for lengths from 300 mm minimum to 720 mm maximum.
This means for rear flueing, the standard kit will accommodate a maximum wall thickness of 600 mm, and for side flueing a
maximum wall thickness of 587 mm. This takes into account the minimum appliance side clearances of 5 mm.
If the flue is a side exit installation, then calculate the position of the hole with a slope of 5 mm / metre towards
the boiler from the terminal. The flue should rise up slightly to the terminal in order to let the condensate come back into the
boiler.
Attention ! Use only specific condensation flue kit.
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