Asked on Dec 24, 2011

Hot Water Circulating Pump

MarkNocalgalWoodbridge Environmental


In remodeling my master bath I want to get "instant" hot water at the shower and lavatory fixtures. I want to have a recirculating pump installed but I want one that will not bleed hot water into the cold water line. What are my options and the pros and cons of each option. Thank you.
4 answers
  • KMS Woodworks
    on Dec 24, 2011

    George this topic can up earlier this year.. some folks will install a "mini" local elec hot water heater...this is fed by the regular fills the gap until the "other" water comes on line. In my home my hot water heater is located just below the "master" bath I have hot water at the tap in about 3 seconds. Homes that are poorly designed often put "mechanicals" is way out of the way places so they are "not in the way" but those locations have their downsides.

  • There are several types of pump systems that you can use. One utilizes a pump on a timer that you turn on so it only runs the water until a sensor sees the hot water then it turns off. Any pump system you use simply draws water off the bottom of the hot water heater tank then returns it back into the supply feed side of the heater once it gets pumped back. Any temp difference can trigger the sensor that runs the heater and turn it back on again to heat the water back up to the setting temp selected. You will need to pipe a water line from the hot water heater up to the bath area in order for this to work. Water is drawn up the hot water supply pipe then pumped back down to the hot water heater through this pipe that is installed. A half inch pipe is all that is needed. With a small Grunfos pump it should only take about 15 seconds for the hot water to delivered to the bath area. Pump can be placed either at the hot water heater, or under the vanity so you do not have to run power all the way from bath to the hot water heater.

  • Nocalgal
    on Jul 5, 2015

    Why do you want the recirculating pump? I have an instant (A.K.A. tankless) water heater that serves 2 bathrooms, kitchen with dishwasher, and clothes washer with no additional pump. nocalgal

  • Mark
    on Jul 14, 2016

    Take a look at WaterQuick Tankless from Faster Hot Water. It is an on-demand system designed for tankless water heaters. You can add a module that will give you instant hot water if that is what you want.

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