Hot Water Recirculating

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    • #272406

      I have a hot water return line going from the farthest fixture back to the water heater. It works fine (heat wise) butI think it’s acting as a supply when the water is turned on. It’s 3/4″, and the pressure is not constant. It also fades from hot to warm to hot again. I installed a check valve, which defeats the system totaly. Is a pump a good solution? How big and what kind of a pump do I need. Where can I get it?

      Thanks for the help

    • #285692

      Pump is usuly recomended.Put pump on return side of last fixture, between the last fixture and the check valve , usuly next to water heater. Pumps can be bought at a plumbing supply or from a plumber. The size of the pump; for res. use usuly a small one will work just fine. Usuly one of 1/3 or 1/4 horse power is more than rnough, 115 volt.

    • #285693

      Help Help
      WE puchased a two story house which is only 5 years old and having servere problems with the Hot water recirculation pump. The pump is made by Laing and has been replaced 5 times. The first time only the pump, then other hardware was added, such as a check valve, position the pump lower, horizontal than vertical etc. it seems that this model only last for 5 to 6 month. Can anyone please help me or recomend a better pump?

      Mike

    • #285694

      Jeff, you need your pipe arrangement looked at by a professional. The water temp should not fade in and out. this seems to be be piped incorrectly. Piping the return line back to the hot water supply can cause this problem.

      Fosscom, a 1/3 to 1/4 horsepower pump will move enough water to heat an apartment building. Recirculator pumps are 1/20 to 1/10 horsepower. A 100-ft length of 3/4-inch tubing holds about 2.5 gallons of water. An insulated line will need about 3/4 gallon-per-minute flow to stay warm. A 1/4 horesepower pump can deliver 20 gpm or more. A 1/4 to 1/3 horsepower pump in such a little line will wear out the large pump.

      The Liang pump usually fails because water is being forced backward through the pump when the water is run, or it is over-running because water is forced through it on the way to the taps.

      The pipe diagram is in the literature with the new pump. One diagram has the recirculating pump in the line pumping toward the water heater cold inlet with a check valve in the same direction the pump moves the water. This prevents flow backward through the line so only hot water is drawn from the heater through the supply line to the taps.

      See: http://www.masterplumbers.com/plumbing/plumbviews/1999/rec_pump.html

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