Rheem RS47-21BP

47 Gallon Passive Solar Water Heater with 21.35 Square Feet Total Collector Area Residential

Item # BCI2143133   |   Model # RS47-21BP   |  Solaraide Collection

Offer Ends

Retail Price: $3,884.25, Your Savings: 20%
Free Shipping!
0 In Stock
Ships in 2 to 3 weeks


Please choose a finish

Score 3,107 reward points with the purchase of this product! Learn More Here

and earn 350pts

Questions about Rheem RS47-21BP?

Contact us for advice or more details. Our product specialists are here to help.

Solaraide Collection Residential Passive Solar Water Heater with 21.35 square feet total collector area and 47 Gallon Tank

Rheem's closed loop passive solar water heating system.

Closed Loop vs. Open Loop

In a closed loop system another fluid (usually a glycol-water antifreeze mixture) is heated up by the solar collector. The storage tank has a heat exchanger that transfers the heat from the other fluid to the water for household use. In an open loop system the water would travel through the solar collector to be heated. The disadvantage of an open loop system is that if the weather drops below freezing then the pipes can burst from the water freezing.

Active Solar vs. Passive Solar

Active solar systems rely on external electrical or mechanical equipment (such as a pump) to assist in converting the solar energy for use. A passive solar system does not use external energy sources, it relies on the solar properties of the system to operate.

The System

With the passive solar design no pumps or controllers are required. The complete system includes tank, collector, installation kit, and heat transfer fluid.

The Tank

The single wall external heat exchanger completely surrounds the storage tank. The tank is rugged steel with a vitreous enamel tank lining. Included is an immersion, copper sheath backup element.

The Collector

The collector is a flat plate design and features 35 multi-flow risers for faster heat transfer. The collector absorber coating is black polyester powder coat.


  • System: 97-1/2" L x 58-1/2" W
  • Tank: 58.5" x 20.1" x 20.1"
  • Collector: 76.3" x40.3" x 3.04"


  • Tank Capacity: 47 Gallons
  • Solar Energy Factor: 1.3
  • Number of Collector Panels: 1
  • Working Pressure (Tank): 145 PSI
  • Delivered Capacity (Solar): 42.3 Gallon
  • Backup Element: 2.4kW, 240V
  • Warranty: 5 Year Limited

Rheem has been manufacturing water heaters since the 1930's, with coast to coast distribution by 1936. Their product offerings cover commercial and residential heating, cooling, solar water heating systems, conventional storage-style water heaters, tankless water heaters, replacement parts and accessories. Rheem's manufacturing facilities are ISO 9001 certified, with four facilities in the United States. Choose an industry leader that is respected for reliability. Choose Rheem.

Additional Rheem Links

This Rheem item can also be referenced by the following color/finish specific model #:

  • Rheem RS47-21BP

*Discontinued model or finish

More Than Just a Store - Your Reasons to Shop

Discover the best online deals for the RS47-21BP and everything else for your home from the leading online home improvement store.

We're committed to providing you with the best assortment of Rheem products with over 400 warehouses across the country.

Our knowledgeable product specialists work to bring you the best prices on every product and provide unmatched customer service. Your satisfaction is our highest priority!

Installation Resource Center

Whether you are installing the product yourself or hiring a professional, our installation Resource Center has everything you need to get your project done. Visit the Installation Resource Center to get started.

Recently viewed items
× Shipping Rates & Methods

The cost to ship items varies by item, shipment and shipping option.

Free Ground Shipping on Orders Over $49 *

Standard ground shipping transit time is 5-7 business days.

Free Freight Shipping on Orders Over $1500 *

Curb side delivery (also called freight or "LTL" shipping) is reserved for large, heavy, or oversized items like chandeliers, bathtubs, shower doors, etc. Items are palletized and loaded onto a large truck for shipment, and delivered to your curb by scheduled appointment. Transit time is 7-10 business days.

* For exact shipping costs, add the product(s) to your cart and enter your zip code. All offers pertain to the lower 48 states and do not include deliveries to Alaska, Hawaii or Canada.

Learn more about shipping rates and policies