Source Select panels
These panels are designed to control two independent heat sources. The Source Select is used when combining
a solar system, geothermal system, wood boiler or other alternative heat source with a gas or oil-fired boiler as a
back up. The primary source, typically, solar or geothermal, must utilize a water storage or buffer tank.
The alternative heat source is utilized first as long as the tank temperature is sufficient. In the event the
alternative heat source is unable to satisfy the system load, the Source Select panel will use the secondary heat
source until the primary source has been replenished. This panel is designed for use with a buffer tank, a Primary
panel, and a Distribution Panel. Source Select panels are typically connected to the inlet side of any HydroNex
Primary panel. A 2-conductor 18 gauge thermostat wire must be connected between terminals in the Source
Select panel relay box and the P-Series panel.
Standard equipment includes:
- 1-1/4” copper primary and 1” secondary piping
- Tekmar 361 mixing control with outdoor reset (only on SS-2 and SS-3)
- Watts Radiant 1558 circulators are energy-saving 3 speed models, pre-wired and tested
- Isolation valves for easy servicing of circulators and easy air purging
- Spring flow check valves on each zone
- Quick connect unions
- 9 ft 120V power cord
- Powder coated steel enclosure
Maximum flow for entire panel is approximately 22 gpm. Maximum flow for each 1" secondary is approximately
8 gpm. Each Watts Radiant 1558 circulator is capable of providing approximately 10 gpm at 10 ft hd.
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