The following is a suggested list of requirements for installing a tankless water heater. Incorrectly installing a water heater could cause damage and even death, We recommend water heaters be installed by licensed plumbing professionals.
Water Heater Permits are usually required when replacing or installing a water heater. Be sure to check with your local Building Department to see if you require a building permit. A water heater permit and inspection is cheap insurance that your water heater was installed properly.
Gas Pipe Input Size of most tankless water heaters is 3/4 inch. If a tankless water heater does not have enough gas it will not operate properly, this is the number one mistake made in tankless water heater installations. It is critical that gas piping is large enough to supply gas to the tankless water heater and the other gas appliances in the house. Most residential gas meters are maxed out when adding a tankless heater and may have to be upgraded
Water Heater Drain Pan is required if the water heater could cause damage if it leaked, and Yes tankless water heater can leak. This means if the water heater is in the kitchen, attic or even in a closet or next to carpeted area, a drain pan should be installed and drained to a safe place. This will save you a lot of trouble and money when the water heater leaks which it will do
Tankless Water Heater Service Valves is must for proper tankless water heater maintenance so don't try and save a few dollars by using ball valves. You will make your money back the first time you flush your water heater.
Earthquake Strapping is not required for wall mounted units but floor mounted units must be bolted to the floor or earthquake strapped similar to a tank type heater. When the water heater is strapped you should not be able to move the water heater.
Flexible Gas Supply Connectors are recommended to help prevent damage during a earthquake. Check to make sure the gas flex is rated for the BTU of the water heater. Be sure to check for gas leaks after installing the gas flex connector and or operating tha gas shutoff valve. Gas shut off valve sometimes develop leaks after being operated. Never use a match or flame to check for gas leaks use a solution of mild dish soap and water.
Temperature Pressure Relief Valve cannot be reused. After installing a new TPR valve be sure to properly pipe the discharge from the TPR valve to a safe location, Uniform Plumbing code requires the discharge to be no closer that 6 inches from the ground and no more than 24 inches. Many localities require the discharge to be piped to the outside of a building.
Flue Piping Must have proper clearance to combustibles. Tankless water heaters use several different types of flue material depending on the manufacture and efficiency rating of the unit. Be sure to use the proper material as required by the manufacture. single wall conductor pipe or class "B" flue piping is generally not acceptable for modern tankless water heaters. Flues for tankless water heaters do not necessarily grade upwards be sure to check manufactures instructions to location, installation and termination of flue piping.
Combustion Air this is the air the water heater uses to burn the gas, with out enough air the water heater will not operate properly. New water heater are under strict environmental requirements, If the don't have enough combustion air they will overheat and shut down. Water heaters require 1 square inch of high and 1 square inch of low combustion air for each 1000 btu input rating of the water heater. Most tankless water heaters require 20 square inches each of upper and lower combustion air. |
