Get to know hot-water systems: a primer

Depending on what kind of system you're running, your hot water could be one of the biggest parts of your energy bill. But maintain your system well, and you can be confident that it'll be running at top efficiency and effectiveness. Here's a primer on some common hot water systems.

• Turn on the hot-water tap of an instantaneous hot-water system and cold water flows immediately into a small heating unit.
• Then, either an electric element or a gas burner, heats the water before it flows into the hot-water pipes and out of the tap.
• This process takes just a few seconds.
• Because they work in short bursts, instantaneous systems are considered more energy efficient than the storage systems that use up a lot of energy to keep a tank of heated water on stand-by.
• Insulating the pipes leading from your heating unit will help improve efficiency.
• For all other maintenance and repairs, you should call a licensed plumber.

• Hot-water storage systems, whether electric- or gas-powered, keep large volumes of heated water on stand-by in a central storage tank.
• Make sure your tank is the right size for your needs: an oversized tank will waste energy and money storing hot water you won't use.
• If you have an older tank, wrap it in an insulation blanket to reduce heat-loss (modern tanks have built-in insulation).
• With these storage systems, you should check regularly to ensure that impurities in the water don't cause the pressure relief valve to seize.
• To do so, lift the lever on the valve until water drains through the discharge pipe.
• Call a plumber to carry out all other maintenance or repairs.

• Solar hot-water systems use solar energy, rather than electricity or gas, to maintain the temperature of a tank of stored hot water.
• Most of these systems are attached to either an electric- or gas-powered booster that kicks into gear when the solar collectors can't collect enough energy to keep the water warm.
• To avoid wasting energy with these systems, remember to turn the booster off when you're away on vacation.
• A new kind of collector made from "evacuated glass tubes" is the most efficient on the market, but the old flat-plate roof panel remains the most popular.
• The collector panels perform best when they're clean and dust-free, so scrub them gently with some detergent on a soft-bristled brush every now and then.

• Heat pumps use the heat in the air to warm water that is then stored in a tank.
• To do this, a small amount of electricity is used to pump a refrigerant around the system.
• This refrigerant then transfers the warmth in the air into the water.
• The less heat there is in the air, the less efficient this kind of pump will be, so these systems are better suited to warmer climates.
• These systems' evaporator must have fresh air passing freely around it so, to keep the system in good working order, regularly check vents around the evaporator to keep dust and debris from blocking them.
• Have a licensed plumber take on all other maintenance and repairs.

Keep this primer on the common kinds of hot-water systems and you'll be equipped to keep yours running at top efficiency and effectiveness.