Close Coupled Hot Water Systems

A close coupled, flat panel hot water system is a very economical water heating solution, especially in Australia. In a hot country like ours, it is relatively easy to convert the energy from into hot water. Mounting (or coupling) the storage tank right above the solar collectors will keep installation cost down, pipes to a minimum and reduce space requirements.


  • Lowest initial cost of all solar hot water systems
  • Less pipes
  • Storage tank out of the way
  • No circulation pump required
  • Low maintenance
  • Available with electric or continuous gas boost
  • Should system ever leak, water will drain into gutters, not into foundation of house

How do close coupled solar hot water systems work?

There are several so called "riser" copper pipes in each collector panel. The water in these riser pipes flows around the blackened panel where it is heated before it enters into the top of the storage tank. The colder water in the tank is thus sucked into the panel and the cycle repeats itself. The principle is known as thermo-syphoning. Once the water heats up too much and expands, a pressure release valve will disperse excess water onto the roof and into the gutters.

Add Frost Protection

If you live in an area where temperatures may drop below zero, you will need a Frost Valve Kit. With this addition, a Rinnai close coupled hot water system can operate in temperatures down to -5°C, making it suitable for nearly the entire continent.

How to proceed?

Rainbow Power Company only supplies solar hot water systems; we do not install. Have a look at our selection of solar hot water systems in our online shop or compile a Rinnai system yourself by answering a few questions to get an instant quote for materials only (excluding pipes). All our prices exclude STCs. To generate STCs, installations need to be carried out by a licensed plumber. If you live in the Northern Rivers, we can refer you to one of our affiliated tradies.

We install solar systems in Northern NSW and Southern QLD.

Gold Coast (from Coolangatta to Southport), Nerang and Hinterland (Beaudesert) and out West (Warwick, Stanthorpe, Killarney)

Northern NSW (Tweed Heads to Yamba, including Evans Head, Byron Bay and Ballina); the Far North Coast Hinterland (Grafton via Lismore to Murwillumbah) and out West (Casino to Tenterfield, including Drake and Tabulam, as well as Woodenbong and Bonalbo)

For larger system we also go up to Brisbane or down to Coffs Harbour and even Glen Innes. Other places by arrangement.