Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

New tankless Noritz98 takes over 5 minutes to get hot water

richardreidlandrichardreidland Posts: 3Member
edited December 2018 in Domestic Hot Water
Just installed a Noritz tankless water heater to the back of my beach cottage. It takes over 5 minutes until the water is hot enough for a shower or to do dishes. I live in Southern California. My house is very small and heater is basically on the wall outside the master bathroom. I'm frustrated....


  • pecmsgpecmsg Posts: 802Member
    Water saving heads and fixtures?

    Whats the minimum Flow rate for that unit?
  • JellisJellis Posts: 121Member
    check the temp at the heater, does the outlet at the heater get hot immediately? or does it take a while also? problem. what is the model number of the unit?
  • richardreidlandrichardreidland Posts: 3Member
    edited December 2018
    The temperature at the heater gets hot in about 30 seconds. It takes over eight minutes before hot water comes into the kitchen sink and it’s not really even that hot I can still hold my hand under it.
    NR98SV is model. I attached paperwork. No water saving heads or fixtures.
  • JellisJellis Posts: 121Member
    edited December 2018
    what is the piping going from the heater to the fixture? 1/2? 3/4?
  • Larry WeingartenLarry Weingarten Posts: 1,513Member
    Hello, This sounds like a plumbing problem rather than a heater problem. If there were a cross connection out in the pipes, the greater flow restriction through the tankless heater will encourage more cold to flow into any cross connection, making the problem worse. Do you have Moen or Mixit valves? Ty this test: Shut off cold supply to heater and open a hot tap. If it keeps running, most likely there is a cross connection or a bad shut off to the heater.

    Yours, Larry
  • bob eckbob eck Posts: 863Member
    What type of water heater did you take out? Tank type or tankless? Did you have this problem with the old water heater?
    Like someone said if hot water is coming out of the TGWH then you most likely have a cross connection. I believe some single handle faucets can cause a cross connection or at the washing machine. Do you have valves at your lava faucets and shower faucets? If so close all of those valves hot and cold. Then at the kitchen faucet see if you get hot water. If you get hot water I would go and turn the valves back on one faucet or shower valve one at a time and see if the water temperature changes. This way you should be able to find where the cross connection is at.
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!