Solex Roofing Installation Manual 29
Solex Energy Ltd +44(0)1305 837223 www.solexenergy.co.uk
The silicone tube may be protected from vermin by sheathing it in an outer tube or
conduit, and it should run in a generally upwards direction to the bottom of the roof.
The silicone pipe should connect to the bottom of the inlet manifold, or the bottom of
the chain of inlet manifolds.
5.
Roof outlet
– this is connected to the top of the outlet manifold or manifold chain. As
long as it starts from the top of the manifold(s), it may run downwards either within the
solar roof, or within the roof space. Like the inlet pipe, it may be protected from vermin,
and there must be a minimum of 500mm outside the hot zone before connecting to
plastic pipe.
Note: manual and auto air vents do not function in this type of system and must not be
used
6.
Cylinder
– the hot flow from the solar roof should go via the expansion tank to the top
of the dedicated solar coil in the hot water cylinder or thermal store.
A sensor for the solar controller must be placed on or in the cylinder/store, at a height
level with the top of the solar coil. See more on cylinders and thermal stores below.
7.
Check valve
– this is used to prevent convective circulation at night. It must go
between the solar roof top outlet and the expansion tank. No other check valves
should be fitted in the solar circuit.
8.
Pressure testing
– it is assumed that the system has been pressure tested with air to
1.5 bar during installation. Note that it is not sufficient to assume that leaks will be
apparent when the system is filled with water, as leaks towards the top of the roof and
in the outlet tube will draw in air and so may go unrecognised while still affecting
system performance. Note, air will diffuse through the silicone absorber, so the
pressure will decrease over time – e.g. overnight the it may drop from 1.5 to 1.0 bar.
9.
Filling and commissioning
– the expansion tank water supply is switched on and the
float valve adjusted to fill the tank to the working level, which should be a depth of
150mm, and the label placed on the outside of the tank.
The pump is set to its maximum setting, and is switched on using the Manual Mode
setting on the controller (below), or by temporarily hard-wiring it if the controller isn’t
installed yet. Check that the pump valves are both on. Water should flow from the
expansion tank, down to the cylinder, up through the roof and back to the expansion
tank. Air will be expelled into the expansion tank.
In the event that the circulation fails and the system does not fill completely, switch the
pump off and on a couple of times to move trapped air. Some systems, especially with
longer cylinder pipe routes may develop an air lock. This may be rectified by bleeding
off near the cylinder, although it must be remembered that if the system will not self-
prime, then there may be occasions in the future when the circulation airlocks.
The water level will rise slightly when the pump is switched off. Any significant and
sustained rise above the working level indicates a leak admitting air into the roof or roof
supply pipes, and should be investigated. Otherwise, the only time the water level
should rise significantly is in an overheat situation, when steam in the absorber will
