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Condensing water heater

kobuck
kobuck Member Posts: 3
I’m trying to understand when the water heater is in ideal condensing operation.
When I turn on the water slow, the blower fan is near silent. Increase the faucet draw and the fan speed will change to a higher speed. Is it more efficient with blower barely running or running fast?
Thanks!
MDL

Comments

  • pecmsg
    pecmsg Member Posts: 4,679
    Make and model?
  • kobuck
    kobuck Member Posts: 3
    Takagi T-H3M-DV-P
    Thanks!
  • hot_rod
    hot_rod Member Posts: 21,818
    It is most efficient when it is not running😗
    Next would be when it is condensing, supplying low flow at lowest useable temperature.

    Think of a vehicle, faster speeds, more stop and go uses more fuel.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Intplm.
    Intplm. Member Posts: 1,790
    kobuck said:

    I’m trying to understand when the water heater is in ideal condensing operation.
    When I turn on the water slow, the blower fan is near silent. Increase the faucet draw and the fan speed will change to a higher speed. Is it more efficient with blower barely running or running fast?
    Thanks!
    MDL

    "Is it more efficient"?
    That depends on the design. And the environment they are installed in.
    These water heaters have four or even five choices or modes of operation.
    The modes are almost always posted with an explanation of what they do for efficiency or the best mode of use for your needs. You can select the modes right from/on the water heater.
    For example: Full hybrid selected would be great when installed in a garage in Florida taking advantage of the surrounding heat to heat the water.
    A cold location mode may best be used in the state of Main, using a combined mode of surrounding heat and electric elements.
    The mode that the water heater is in and the water heater's surroundings will dictate the condensing.
    Larry Weingarten
  • kobuck
    kobuck Member Posts: 3
    Intplm, my water heater only allows for temperature adjustments. It’s a basic tankless water heater.
    I guess I’m trying to understand why the blower speed increases with water demand and does it condense better at low or high blower speed.
    Thanks for explanations. Just interested in learning how it works!
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,229
    Hi, Just guessing, but if the burner is not just on or off, and can modulate, than the fan could be adjusting speed to match burner output. Bigger flame needs more venting.

    Yours, Larry
  • Intplm.
    Intplm. Member Posts: 1,790
    @kobuck. Maybe send some pictures and post them here. We can get a better idea of what you have.