We have straightened out our share of do it yourself water heater installations. A few of those are fellow plumbers who do not specialize in water heater installation. When we do our installs, we make sure everything is to code. Making sure the water heater is hardwired (eliminating the plug in style, like a dryer cord). A disconnect is necessary if you’re not able to see the electrical panel from where the water heater is located. If you have a double 20amp breaker, you should use a water heater that has 3500 watt elements, if you have a double 30amp, you should use a 4500 watt element water heater.. If there is a backflow preventer, you should have a relief valve that releases at 120lbs or an expansion tank, to absorb the additional pressure created when the water heater is heating. The following pictures show an expansion tank and a relief valve. pressure relief valve
If you plan on installing an expansion tank the pressure in the tank should be equal to the line pressure into the house, if this is not calibrated properly, then the expansion tank will not work properly. If installing the relief valve, it should be installed outside where It can drain in case of excessive pressure build up. Both of these items should be installed on the cold water side of the water heater. Water heater pans are required in condos or if you have elevated areas in the garage. So, as you can see there can be more involved in the installation of a water heater then you may have thought. Trust in the professionals! We here at All Pro Water Heaters will make sure your water heater is installed properly. This will in some cases extend the life of the water heater and it will function the way it was designed.