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Do You Need To Descale A Tankless Water Heater?

how to descale massachusettsIf you have a conventional water heater (one with a storage tank), one of the most important tasks you have is to periodically flush it so that mineral deposits (“scale”) won’t accumulate on its heat exchanger (scale reduces efficiency and shortens the lifespan of your equipment).

The question is, do you need to flush a tankless water heater, even though it doesn’t have a storage tank?

The answer is yes.

Scale forms when heat separates calcium from water – and that process happens the same way in a tankless water heater as it does in a standard water heater model. Even a thin layer of scale could drop your efficiency by as much as 30 percent, essentially negating the advantage of using a tankless vs tank system.

The good news is that descaling your tankless water heater is pretty easy to do. Before you try it yourself, always read the instructions the manufacturer gave you first! While the procedure detailed below is fairly standard, there might be slight but important variations based on your particular model.

If you’re not comfortable tackling this procedure, don’t worry – we can take care of it for you. Just give us a call!

Materials Needed For Tankless Descaling

  • A tankless water heater flush pump
  • Rubber or washing machine hoses to attach to the valves
  • A water collecting bucket
  • Vinegar or a tankless water heater descaling solution
  • A channel lock wrench

Descaling A Tankless Water Heater

  1. Before you begin, set your temperature to 150°F and let hot water run through the heater for about a minute.
  2. Shut off all the power to the water heater.
  3. Close the incoming and outgoing water isolation valves. If your unit doesn’t have isolation valves, then you can buy some and install them yourself.
  4. Have a bucket ready to collect water as it drains. There will be about a liter of water or so in the pipes of the tankless heater.
  5. Drain the unit and connect hoses to the drain ports of the isolation valves “A” and “B”.
  6. Dump this bucket or have another bucket ready to go with a solution to be pumped through the heater.
  7. Fill an empty bucket with a mix descaling solution and water. About half a bucket of water will do the trick.
  8. Open the isolation valves A and B.
  9. Turn on the circulation pump. Let the solution circulate through the tankless water heater for at least 30 minutes, but an hour is better.
  10. Drain the descaling solution from the heater and flush fresh water through the heater by closing valve “B”.
  11. Open up valve “A” with a hose leading to an empty bucket.
  12. Open up the inlet water valve to let fresh water flow through the unit and empty it into the empty bucket to get all of the solution out of the heat exchanger.

A good flush is important, but it isn’t the only maintenance your water heater needs! Be sure to contact a water heater maintenance expert a minimum of once every two years for a conventional water heater, and once a year for a tankless water heater. Contact FSi today to schedule an appointment for water heater maintenance in Greater Springfield, MA!