Technical data

The sequence of valve operation for a single manifold is slightly different from larger manifolds. Each

slinky is connected to a three port diverting valve as above. The slots machined on the front of each valve

indicate which connection is open. The previous drawing (Fig 25) is set for normal operation, i.e. both

purge connections are closed and the flow and return from the slinky to the heat pump are open.

i. Remove the plastic blanking plugs, and connect the purge pump to the fill and purge ports on the

Slinky manifold, see Fig 25 above. The purge ports can be connected either way round.

ii.

Connect the purge pump to draw from an 80 litre dustbin half filled with clean water. This pump

must be capable of circulating 60 litres per minute against a pressure of 1 bar. If the pump’s

electrical rating is less than 1 kW, then it is unlikely to be suitable. Vent-Axia only recommend the

use of the Clarke CPE130SS pump for this. The water level in the dustbin will need to be topped up

constantly during the following process. The pump may need priming by pouring water into its

priming port until it overflows.

iii. Place a filter such as a kitchen sieve over the pipe returning water to the dustbin so any debris will

be captured. To move the position of the valve an adjustable spanner can be used. Open the valves

on the manifold to the following position:-

Start the purge pump, being careful that the return pipe to the dustbin is secure.

iv. If the water level in the dustbin does not start to drop, then you need to repeat the pump priming.

The flow rate should be in excess of 30 litres per minute. This can be checked simply by holding a 10

litre bucket to collect water returning from the slinky, and ensuring that it fills in less than 20 sec-

onds. If the flow is less than this, sufficient velocity is not being achieved to displace the air at the

tops of the slinky coils.

v. After water has circulated for about ten minutes, and no more debris has collected in the sieve,

place the return pipe below the water level in the dustbin to ensure all the air has also been

expelled.

Turn the pump off and move the valves on the manifold to the positions below, again ensure that

the return pipe into the dustbin is secure.

Start the pump and purge the heat pump of air.

vii. After the air has been removed it is advisable that before the antifreeze is added the system is leak

tested at 5 bar for 15 mins.(See 5.1.2.1).

Both purge connections are now open to ground array

Fig 26 Purging the

Slinky of Air

Fig 27 Slinky Purged of Air

Both slinky connections are now closed. Purge ports open to heat pumps.