Ever had to take a cold shower because your hot water heater went out? Well then you know that your water heater is one of the most crucial parts of your plumbing system. You may also know that a water heater can be expensive to replace.

A water heaters job is to heat water, either with electricity or natural gas. But, when water is heated, it expands. It’s called “Thermal Expansion”.

A typical water heater size for a home is 40 gallons. When your hot water heater heats water from 70 degrees to 120 degrees the water may expand by an extra half gallon of water. If the excess water doesn’t have anywhere to go, like a thermal expansion tank, it increases the pressure in the pipes. Sometimes the pressure gets so high that it could cause problems.

If you have a “Closed Water Heating System” with a check valve or a “Backflow Preventer” on the incoming water line, thermal expansion will create additional water volume which will have no were to go. This will increase the water pressure in your pipes and may cause your plumbing problems. Your relief valve on your water heater may drip or run. When the water pressure gets up to 150 psi, the valve will automatically release the extra pressure. But this valve may fail if it’s consistently used. The relief valve is a safety valve and not designed to be used repeatedly.

One of the signs that you’re having thermal expansion issues is that your toilets keep running or kicking on. The float on the fill valve in the tank of your toilet will be overcome by the water pressure and water will run into your toilet tank. If this happens for a period of time the toilet fill valve will stop working, and your toilet will run continuously.

New California building codes require that when replacing a water heater or installing a hot water heater for the first time that a “Thermal Expansion Tank” must be installed in line with the hot water heater. A thermal expansion tank is just a small tank that holds your hot water “overflow”, when your hot water expands.

As of Jan 1 a thermal expansion tank is required on all new and replacement hot water heaters. This has raised the cost for a new replacement water heater has gone up. To help out with the increased costs John Stevenson Plumbing is offering $100 off a replacement water heater installation until February 28, 2011. Use discount code: BLOG   Looking for a Carlsbad Plumber? Please call us today at 760-452-0702 to schedule a visit.