Solar Skies Mfg, LLC
106 Donovan Drive • Alexandria, MN 56308 • Ph 320-762-1151 Fax 320-762-1460
CD1065.doc Last Revision: 12/23/2010
INTRODUCTION
Drain back tanks are designed to allow solar collectors and related piping to drain heat transfer fluid into the drain back
reservoir when not in use.
Drain back systems are versatile: ideally suited for both cold and warm regions. The drain back process protects solar
system components from both freezing and overheating, and saves power by shutting down the solar system when there
is no longer a demand for hot water. Drain back systems have fewer components than pressurized systems, making drain
back systems easier to use, service, and maintain.
Your drain back tank may come with an internal heat exchanger (for use with a storage tank), or without a heat exchanger
(for use with either a solar water heater with an internal heat exchanger or a storage tank with an external plate and frame
heat exchanger).
Job site conditions will require your installation contractor to supply some or all of the following:
Plumbing Connections
Piping and Insulation
Valves Between the Existing Domestic Water System and the Drain Back Solar System
PART 1: GENERAL SAFETY INFORMATION
A. PRECAUTIONS
NOTE:
OBTAIN ALL APPLICABLE PERMITS AND OBEY ALL LOCAL CODES.
NOTE:
Install all system components and piping in such a manner that does not reduce the performance of any fire rated
assembly.
If any system component(s) is/are exposed to the following, do not operate until the affected component(s)
has/have been inspected by a qualified serviceman.
1. FIRE
2. DAMAGE
3. SUBMERSION IN WATER
Any claims for damage or shortage in shipment must be filed immediately against the transportation
company by the consignee.
Ensure there are no low points or dips in sloped non-vertical supply and return pipe runs from the solar
collectors to the drain back tank. Low points and improperly designed solar piping can trap water and
possibly rupture in freezing weather. Pitch non-vertical piping ¼” per foot towards the drain back tank to
facilitate proper drainage, and take care to properly layout piping to ensure there are no low points.
In addition, the drain back tank and solar storage tank must be protected from freezing temperatures. Care
must be taken when filling the system to avoid overfilling and exposing pipes to a freezing condition.
NOTE: SOLAR SKIES MFG. DOES NOT WARRANT THE DRAIN BACK TANK AGAINST FREEZE
RELATED DAMAGE.