plastic pipe is prohibited. Di-electric nipples
may be required by the (Authority Having
Jurisdiction) AHJ on the potable side.
Hard copper connections to the city cold water
supply line and the home hot water feed lines
are recommended. The gaskets in standard
water heater flex hose connectors can become
brittle and compressed over time and begin
leaking on the water heater. If not detected in
a timely manner even a small drip or leak may
cause serious damage to the tank’s electrical
components or, in extreme cases, may cause the
tank to leak from the outside in.
Tank plumbing is required to provide for the
isolation of the solar storage tank from the city
cold water supply line by means of an isolat-
ing ball valve (COMPONENT #23, FIGURES
15A; 15B; 16A; 16B; 17A; 17B ).
The differential temperature controller shall
have a screen readout to show temperatures of
the collector and storage tank. Otherwise, line
thermometers shall be installed in the collector
supply and return lines to allow for a simple
diagnostic check of proper system operation.
On a sunny day the hot water return line should
be approximately 5°F – 12°F warmer than the
water in the collector supply line. Compare the
temperature readings in the two line thermom-
eters (COMPONENT #3, FIGURES 15A; 15B;
16A; 16B; 17A; 17B).
A high quality thermostatic mixing valve is a
required component in all OG-300 certified sys-
P.14
Hot Water
Return Line
Sensor Wire
Must NOT
Be
Placed In Direct Contact
With Pipe
Crimp Or Solder Connection
- Use Heat Shrink If In
Exposed Location
Silicon Sensor Lead May Be
In Contact With Pipe
Sensor Clamped to Collector
Header Pipe & Covered With
Insulation
Protective
Insulation Jacket or
Approved Coating
COLLECTOR SENSOR
fig. 12
