Solar upgrades to existing gas and electric hot water systems

Yes. You can tie up a solar upgrade to your existing gas (or electric) water heater system. Solar upgrades are increasingly common but not always easy to accomplish. Things may not be as simple as some manufacturers like to put it.

Solar Upgrade Kits

Be aware. Solar upgrades are not simple plug and play operations... They pose compatibility problems and design issues. New systems and designs may not work with older water heaters and boilers. They often require adaptations.

Solar Retrofit Drainback System Manufacturers are now offering solar retrofit kits for existing gas and electric heaters, with very tempting prices. But before upgrading pay attention to some preconditions.

Solar upgrades require a proper water pressure, and manufacturers are now offering boilers and gas water heaters especially designed to respond to it, but that wasn't the rule some years ago (and still isn't).

See, on this issue: Solar backup systems.

The principles of a solar Upgrade

In a solar upgrade the existing gas or electric system becomes a backup system that uses preheated water, supplied by the solar system... In other words: the backup system operates whenever the solar preheated water needs a boost in temperature (associated to peaks of demand and whenever the solar sub-system isn't working in its full capacity due to lack of sunlight).

To achieve it, the existing water heater (or boiler) should be able to respond to the temperatures of the hot water produced by the solar system... And that's when problems come or adaptations may be needed...

Modifications in the existing hot water system

Solutions and modifications vary a lot. All depends on the existing system, on climate considerations, or on the exact goals...

In some cases the solar upgrade demands the installer to replace the existing hot water cylinder with a dual coil solar cylinder or with a modern solar compatible water heater or boiler...

Some solar installers may also consider solutions involving a retrofit coil, or a "four way connectors" combined with a controller, able to switch a pump on and off according to the amounts and temperatures of the hot water produced by the solar upgrade...

Other modifications demanded by the solar upgrade

A certified solar installer should provide you with the right design and the most suitable modifications, responding to your needs, goals and climate.

Installing a solar upgrade may even require the reinforcing of the roof, and the compliance with solar law requirements (permits and other requirements involving the plumbing work, the roof or other areas).

Other considerations

As said before, solar upgrades should respond to your needs and to your climate, but also to requirements for efficiency (good location of the solar panels, proper orientation and tilt...) or to the impact that elements like the shade of trees or walls and buildings can have.

If, for instance, you live in a cold climate you can't have the solar design that people in moderate or hot climates have. A drai nback or a glycol solar design is a good solution for colder climates, but not for moderate or hot climates...

See, on these issues: Solar designs

The solar upgrade cost

Solar upgrade kits are increasingly cheap, but modifications in the existing system or installation costs end up making final prices much higher.

Solar Upgrade warranties

Solar upgrade warranties do not differ from those of new solar systems.

Solar panels have long warranties (10 years minimum) but pumps and other components have much shorter ones (1-2 years...). The most important is to choose certified and qualified products and components: Energy Star solar water heaters, UL and IEC components. And to verify and be aware to design and compatibility issues.