Connection Of Pipework - OSO Super S Installation Manual

4. Pipe Connection & Commissioning
Before connecting the cold supply, flush the cold supply pipework of all flux and debris.
Lift off the cylinder lid allowing access to the combination valve and other connections.
4.1 120-250 l.: Check the expansion vessels and hose connections are tight. 300 l.: Fit the expansion vessel and
bracket on a suitable wall close to the cylinder. Connect the flexible hose to the expansion vessel.
4.2 Remove the template and position the cylinder to meet the heating and domestic water pipes.
4.3 Combination valve.
The Combination valve at the top of the cylinder is factory fitted and is water-tight. If necessary it can be rotated in either
direction to suit the connecting pipework, up to half a turn without losing its seal.
4.4 Cold mains supply.
Connect the cold mains supply to the combination valve cold feed (Fig. 3).
4.5 Hot water outlet.
Connect the hot water distribution pipe to the combination valve hot
water outlet (Fig. 3).
4.6 Balanced cold water supply (optional).
If no balanced cold supply is required, tighten the supplied blanking cap. If a balanced mains pressure cold water supply
is required to a shower or bidet (over rim type only, ascending spray type requires type AA,AB or AD air gap), remove
blanking cap and connect to the shower or bidet cold supply on the combination valve (2).
(Major shower manufacturers advise fitting a mini expansion vessel in the balanced cold supply pipework to accomodate
thermal expansion and prevent tightening of shower controls) Using the balanced cold connection to feed bath taps can
reduce the flow available to the unvented cylinder.
4.7 Flexible Y-hose
The flexible Y-hose is preformed to the correct shape. Connect the inlet ends to the expansion relief valve and the
temperature and pressure relief valve.
4.8 Tundish
Recommended position of the tundish is to the left of the cylinder as seen from the front. Connect the tundish inlet to the
outlet end of the flexible Y-hose. Tundish should be visible and positioned away from electrical devices. Tundish can be
secured with supplied screws.
4.9 Discharge pipe
Connect the tundish outlet to the discharge pipe. Install the Tundish in a vertical position within a maximum of 500 mm
from the Temperature and Pressure Relief Valve drain connection. Ensure the expansion relief pipework discharges
through the tundish. Tundish pipework must be 22 mm with a minimum vertical length of 300 mm below tundish.
Maximum permitted length of 22 mm pipework is 9 m. Each bend or elbow is equivalent to 0.8 m of pipework. All
pipework must have continous fall and discharge in a safe, visible position. If any doubt, refer to Building Regulation G3.
Discharge pipe must be dedicated to the cylinder and must not be used for any other purpose.
4.10 Primary flow & return and motorised valve (Indirect only)
Fit the elbows supplied to the primary flow & return connections. Make the boiler primary flow and return pipes to the unit.
The motorised valve can be connected to either the primary flow or return pipe. Ensure that the direction of flow is correct.
It is possible to fit the motorised valve on the flow pipe on its side to fit under the cylinder lid. For electrical connection of the
motorised valve and immersion heater, please read Electrical Installation Instructions. (Pages 5-9)
4.11 Secondary return (optional)
If a secondary return is connected, the cylinder thermostats should be set to a
maximum of 60°C. Reduce thermostat settings to 60°C on direct units.
A secondary return can be connected by a T-piece to the combination valve.
Remove the flexible hose from the combination valve and connect T-piece.
Connect the flexible hose to the T-piece and connect 15mm copper secondary
return to the remaining T-piece outlet. An additional expansion vessel will be
required if the secondary return "loop" exceeds 10% of the cylinder capacity.
1 metre of 22mm pipe holds approximately 1/3 litre of water. 15 mm pipes carry
approximately half that volume. Secondary return must be pumped by a bronze
pump and fitted with non return valves to ensure correct direction of flow.
4
F . 3
ig
F . 4
ig
Cold mains
supply
Hot water
outlet
Balanced
cold water
T-piece conn.
(120-250 l. only)
Flexible hose
Fit additional
T-piece here
for optional
secondary
return.