You may be considering installing a tankless water heater in your home in order to save money on your utility bills. Tankless water heaters are convenient and take up little space, but the installation of gas-fueled models is more complex than a traditional water heater installation. Tankless water heater venting must be done correctly to ensure safe and efficient operation of the unit.
Here are a few things your installer should consider for effective tankless water heater venting:

  • Vent to the outside.
  • No common venting. The tankless heater cannot share vent piping with any other appliance, and it cannot use a masonry chimney flue for venting.
  • Special stainless steel pipe. The vent pipe must be made of stainless steel designed for venting corrosive gases. The standard galvanized vent from your old storage tank heater would quickly rust away if your tankless heater vented through it.
  • Downhill slope or condensate drain. Your vent should slope slightly downhill from the water heater’s heat exchanger or be constructed with a condensate drain near the exhaust outlet. This is to keep condensate from draining back into the heater. Failing to keep the heat exchanger clear of corrosive condensate will shorten its life by years.
  • Short vent run. The vent should be as short as possible to ensure complete exhaust of combustion gases from the home. Since the stainless steel vent pipe is much more expensive than the gas supply and water supply piping, it makes sense to move the tankless heater closer to where the vent will leave the house. You will need less vent pipe that way, even though you will need more water and gas supply piping.

Call us at Modern Mechanical for help with your tankless water heater installation or other heating and air conditioning projects. We serve homeowners throughout Northern Virginia, as well as in parts of Maryland.