CONNECTIONS – PLUMBING
43
Exposed pipe work between the solar storage tank and the penetrations through the roofing material should
be kept to a minimum to maintain the aesthetics of the installation.
Pipes must not be installed in direct contact with metal roofs. Where it is necessary to run piping across a
metal roof, it must be fixed above the roof and surrounded with a weatherproof insulation. The insulation must
be UV resistant if exposed. The insulation is to assist in freeze protection and to protect the metal roof against
corrosion by water runoff over the copper pipe. Consideration should be made for thermal expansion and
contraction of the roof material.
Pipe work, including that within the roof space, is to be securely fixed to prevent vibration.
PIPE SIZES
To achieve true mains pressure operation, the cold water line to the water heater should be the same size or
bigger than the hot water line from the water heater.
The pipe sizing for hot water supply systems should be carried out by persons competent to do so, choosing
the most suitable pipe size for each individual application. Reference to the technical specifications of the water
heater and local regulatory authority requirements must be made.
IN-SERIES BOOSTER (IF INSTALLED)
The pipe work between the solar storage tank and an in-series booster has a minimum recommended pipe
size of DN20,
MUST BE
of copper and be fully insulated with a closed cell type insulation or equivalent and in
accordance with the requirements of AS/NZS 3500.4. The insulation must be weatherproof and UV resistant
if exposed. The insulation must be fitted up to the connections on both the solar storage tank and the in-series
booster. An isolation valve must be installed on the water line to the in-series booster. The isolation valve must
be of a full flow type if the in-series booster is a continuous flow water heater.
TEMPERATURE PRESSURE RELIEF VALVE
The temperature pressure relief valve is supplied in the pipe kit. The temperature pressure relief valve must
be fitted to the end of the hot water Tee before the water heater is operated. Before fitting the relief valve,
make sure the probe has not been bent. Seal the thread with an approved thread sealant such as Teflon tape
- never hemp. Make sure the tape does not hang over the end of the thread.
Screw the valve into the hot water Tee (refer to the
installation diagrams on pages
to
26) leaving the valve
drain pointing downwards and away from the electrical cover. Do not use a wrench on the valve body - use
the spanner flats provided. A copper drain line must be fitted to the temperature pressure relief valve (refer to
on page 44). The drain line
must not
be installed in front of or prevent access to the
electrical cover of the water heater.
The valve must be insulated with closed cell polymer insulation or similar (minimum thickness 9 mm) and the
insulation installed so as not to impede the operation of the valve. The insulation must be weatherproof and
UV resistant if exposed.
EXPANSION CONTROL VALVE
An expansion control valve is supplied in the pipe kit and must be installed. Install the expansion control valve
using a brass Tee, brass union and brass nipple on the cold water line to the water heater.
The expansion control valve must always be installed after the non-return valve and be the last valve installed
prior to the water heater (refer to the
cold water connection diagrams
on page 42). A copper drain line must
be fitted to the expansion control valve (refer to
on page 44).
The expansion control valve and its easing gear must be accessible from ground or floor level. It must not be
installed either on the roof or in the ceiling space, unless it is an accessible trafficable area. Extend the cold
water line from the expansion control valve to the cold water inlet fitting on the solar cold pipe.
The valve, if installed within 500 mm of the water heater, must be insulated with closed cell polymer insulation
or similar (minimum thickness 9 mm) and the insulation installed so as not to impede the operation of the valve.
The insulation must be weatherproof and UV resistant if exposed.