CONNECTIONS
–
PLUMBING
39
RELIEF VALVE DRAIN
DN15 copper drain lines must be fitted to the temperature pressure relief valve, expansion control valve (if
one is installed) and solar circuit relief valve to carry the discharge clear of the water heater. Connect the
drain lines to the valves using disconnection unions. The drain line from the valve to the point of discharge
should be as short as possible, have a continuous fall all the way from the water heater to the discharge
outlet and have no tap, valves or other restrictions in the pipe work.
A drain line from a relief valve must comply with the requirements of AS/NZS 3500.4.
A drain line must be no longer than 9 metres with no more than three bends greater than 45° before
discharging at an outlet or air break. The maximum length of 9 metres for a drain line is reduced by 1 metre
for each additional bend required of greater than 45°, up to a maximum of three additional bends. Where the
distance to the point of final discharge exceeds this length, the drain line can discharge into a tundish.
Subject to local regulatory authority approval, the drain lines from the temperature pressure relief valve and
expansion control valve from an individual water heater may be interconnected.
The outlet of a drain line must be in such a position that flow out of the pipe can be easily seen, but arranged
so discharge will not cause injury, damage or nuisance. The termination point of a drain line must comply
with the requirements of AS/NZS 3500.4. Drain lines must not discharge into a safe tray.
In locations where water pipes are prone to freezing, drain lines must be insulated, must not exceed 300 mm
in length and are to discharge into a tundish through an air gap of between 75 mm and 150 mm.
If a drain line discharges into a tundish, the drain line from the tundish must be not less than DN20. The drain
line from a tundish must meet the same requirements as for a drain line from a relief valve.
Warning:
As the function of the temperature pressure relief valve on this water heater is to discharge
high temperature water under certain conditions, it is strongly recommended the pipe work downstream of
the relief valve be capable of carrying water exceeding 93°C. Failure to observe this precaution may result in
damage to pipe work and property.
GAS INLET
The gas connection is made at the underside of the gas
booster. The pipe work must be cleared of foreign matter
before connection and purged before attempting to
operate the water heater. An isolation valve and
disconnection union must be installed to allow servicing
and removal of the water heater (refer to the
39).
Note:
Refer to the Gas Installations Standard AS 5601 or
AS/NZS 5601.1 for the correct method of sizing the gas
supply pipe to the water heater. The pipe size selection
must take into account the high gas input of the gas
booster
other gas appliances in the premises.
Warning:
Always isolate the gas booster before
pressure testing the gas supply system. Disconnect the
gas booster after the isolating cock to prevent the risk of
serious damage to the gas control. The Solahart warranty
does not cover damage of any nature resulting from failure
to observe this precaution. Refer to rating label for gas
types and pressures.
gas inlet
