Tankless Water Heater Plumbing Requirements

How to determine the required size of a tankless hot water heater.

Tankless water heater plumbing requirements.

If you use less than 41 gallons of hot water per day a tankless heater is 24 34 more efficient than a tank style heater. This valve should be connected to a tube that discharges no more than six inches above floor level so hot water won t scald anyone nearby. Measure your cold water temperature. Below we ve highlighted what size water heater you would need in our example of 6 5 gpm at a 63 f temperature rise.

Tempra series tankless water heaters are designed to use the same 208 240 volt current that your conventional electric tank type water heater uses however it will require a larger breaker and likely a heavier gauge of wiring. Beyond a water heater permit some areas may also require either an electric or plumbing permit depending on the type of water heater. Typically hot water flows from a tankless heater at the rate of 2 5 gallons per minute and that may not be enough for several simultaneous uses of hot water in your household. Determine your water flow rates.

A full bore shut off valve is required on cold water side unions must be installed within 12 inch of water heater to facilitate removal first five 5 feet of water line insulated maintains min. If you use a lot of hot water around 86 gallons per day tankless water heaters are only 8 to 14 more efficient since they are running more often. If the window does not open the tankless water heater clearance from a window requires a 12 inch setback. I e rinnai requires 120 vac and 60 hz from the adequately grounded circuit.

Tankless water heaters are much smaller than units with a storage tank allowing them to be wall mounted. If reticulating pump in system. Tankless water heaters should not be installed near dryer vents or intake air vents. Tankless water heater pressure temperature relief valve safety requirements the temperature pressure relief valve lets water escape if the temperature or pressure is too high.

Insulation is applied to the entire loop. Once you have your total flow rate and the required temperature rise you can find the right size tankless water heater for your home. Tankless water heater vent clearances if the unit is vented to the outside then it needs 12 inches of clearance from a door or window. Determine the mounting space.

For example taking a shower and running the dishwasher at the same time might stretch a tankless water heater to its limit. Many water heaters especially traditional electric ones require changes to your wiring and potentially the breaker box.