Question about RTO American Heat Tankless Electric Water Heater

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Water Temperature Fluctuates

American Heat Model AH18 works fine except in bath tubs. The water temperature fluctuates costantly. Is this a pressure problem?

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  • scm7001 Mar 10, 2009

    Even at the lowest temperature setting, the hot water comes out scalding...and on occasion, the water comes out barely lukewarm. After calling AH support, I was told that it is possible some sediment has clogged up the temp sensor...

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We have installed over 2 dozen of these in a condo project....we actually made our own flow restrictors for tubs for this problem....gotta slow the water down! That's the key to using tankless. The slower the water moves through the heater, the hotter it will be. We modified sink restrictor and put in our tub spouts.

Posted on Oct 03, 2009

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No the tub faucet is the only faucet that is wide open you might have to not run full blast on the faucet , your tankless water heater is under sized for the application, to many gallons per min going thru the unit, look at the rating chart for your unit, the r94 is only 9.4 gallons per min, and a tub faucet can be upto 5 gallons per min, depending on the faucet,,

Posted on Jun 06, 2009

  • gary miller
    gary miller Jun 06, 2009

    no the tub faucet is the only faucet that is wide open you might have to not run full blast on the faucet , your tankless water heater is under sized for the application, to many gallons per min going thru the unit, look at the rating chart for your unit, the r94 is only 9.4 gallons per min, and a tub faucet can be upto 5 gallons per min, depending on the faucet,,

  • gary miller
    gary miller Jun 06, 2009

    no the tub faucet is the only faucet that is wide open you might have to not run full blast on the faucet , your tankless water heater is under sized for the application, to many gallons per min going thru the unit, look at the rating chart for your unit, the r94 is only 9.4 gallons per min, and a tub faucet can be upto 5 gallons per min, depending on the faucet,,

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