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Grundfos Comfort Series Hot Water Recirculator

Dave_4
Dave_4 Member Posts: 1,405
between water savings and gas savings. I find it hard to believe that the comfort valve will cause gas bills to go through the roof. Supposedly one can save thousands of gallons of water per year in not running the hot water until hot water actually comes out.

Comments

  • Bob Schultz
    Bob Schultz Member Posts: 38
    Choosing a Hot Water Recirculator based on outlet availability

    Have you installed the Grundfos Comfort Series Instant Hot Water Recirculator or the WATTS Premiere Instant Hot Water Recirculator. Both of these systems use a comfort valve or sensor valve which gets installed at the farthest sink from the water heater. Comfort valves / sensor valves close once hot water reaches them. This prevents hot water from entering into the homes cold water line. We also agree that these valves are open anytime cold water is in the hot water line. In order to keep these valves closed we would have to have hot water in our hot water lines 24 hours a day. Having hot water in the hot water line “all the time” is just not energy smart and would seriously raise a homes gas bill.

    Here’s some valuable information unknown by most plumbing professionals. We installed a comfort valve underneath the sink farthest from the water heater. We made sure that the pump which was mounted on top of the water heater was scheduled-off and would not run during this test. We first measured the temperature of the water coming out of the hot water faucet. It was 70 F degrees. We then opened only the COLD WATER faucet and let it run for 2 minutes. After two minutes had passed, we closed the cold water faucet and immediately checked the temperature of the water coming out of the hot water faucet. The temperature had gone from 70 F to 88 F. How can that be…we only used the cold water faucet? That just doesn’t make sense, right?

    Now here is what so many people don’t realize until they think about it.

    When cold water is used or a cold water faucet is opened the water pressure in the cold water line drops. And, since the water pressure in the hot water line is higher, it easily passes through the comfort valve and into the cold water line and out the cold water faucet. All because the cold water in the hot water line kept the comfort valve open and allowed the crossover to occur. This crossover continues until hot water from the water heater reaches the comfort valve and closes it. What does this mean?

    This means that anytime you brush your teeth, use the toilet, water the grass or use cold water anywhere in the home…and the water in the hot water line is cold …water from with in the hot water line will crossover into the cold water line. More importantly, every time this happens, your drawing water from the homes water heater, causing very cold city water to enter into the water heater needlessly, raising the homes water heating bill. It’s this inefficiency that is causing homeowners to complain their gas bill has gone through the roof and that they no longer have cold water in their home.

  • Al Letellier_9
    Al Letellier_9 Member Posts: 929
    hot water recirc

    We have installed many of these units (Grundfos) will none of the problems you mentioned. If this was a problem with this unit, how did it get UL approved and accepted by all the various plumbing codes?
    Did you change out the tee or look for another problem? I have one in my home with no problems whatsoever, and being a plumber, I think I would notice it.

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  • Joe Mattiello_2
    Joe Mattiello_2 Member Posts: 94
    Taco D'mand pump

    Try the Taco D’mand pump as a comparable alternative without the bypass issue. For your reference I have attached the catalog data information.

    Joe Mattiello
    Technical Support Technician
    Tel. 401-942-8000 X 484
    Fax. 401-942-2360
    1160 Cranston St
    Cranston, RI 02920
    joemat@taco-hvac.com
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