tankless-luke warm shower

Discussion in 'Tankless Water Heater Forum' started by wt, Jan 30, 2009.

  1. Redwood

    Redwood Master Plumber

    Joined:
    Dec 15, 2007
    Occupation:
    Service Plumber
    Location:
    Connecticut
    And you reply to this?
    Now you have really outdone yourself in your twisting of facts and information resources. Your post is so full of incoherant ramblings of quoted misapplied information that a person reasonably educated could hardly understand it.

    I propose that we bestow the title of "Google Boy" upon you.

    This is a title that we give to those with a total lack of subject knowledge that manage to post "copy & paste" a long post that looks very knowledgable on the surface until a knowledgable person attempts to read the assembled drivel.


    Simply put Legionella Bacteria is present in water. Usually in small quantities that have a miniscule chance of causing a problem. When water is stored at a temperature in the ideal growth range the small amount present can multiply.

    The use of a tankless water heater will not do anything to the bacteria to kill it and infact if there is a recirculation system may keep it in the ideal growth range just like a tank type water heater.

    The solution is simple for a tank type water heater and that is to raise the temperature in the tank to 140 degrees where the Legionella Bacteria will be killed then youe a tempering valve on the outlet to lower the temperature to 120 degrees for safe use.

    There it is a few simple paragraphs that said more than all the drivel you posted...
    Could it be that I know my subject matter and am qualified to post about it?
     
  2. Ladiesman271

    Ladiesman271 Homeowner

    Joined:
    Aug 22, 2008
    Occupation:
    Care and maintenance of transformers

    From what I can tell, it is clear that you do take pride in doing things to code!
     
  3. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Joined:
    Nov 20, 2008
    Occupation:
    Chicago Illinois Licensed Plumber
    Location:
    Chicago, IL
    Sad part about Tankless heaters is the code does not address properly sizing the heater as of yet. Having them singing the disclaimer that I had informed them the system the want installed is not the one they where advised by me to install. It has help up in court as part of the contract, and some of the people did have me come in and install the system as advised. Others changed their usage habits as well as installed flow restrictors everywhere. 1 gpm shower heads .5 gpm aerators and so on. Just so the single unit can handle their demand. Once the code address this issue then I can tell the customer sorry I can not install this the way you want it installed.

    Now for restaurants that go tankless do a hybrid set up there. We have two units one direct feeding the bathrooms each with a .5 gpm aerator. The second tank is tied into a 180 Gallon storage tank with recirculating pump and a thermostat on the tank maintaining the water to the required 160 degree water if they use a chemical sanitizer, or to 180 degrees if they just use a hot water rinse on their dishwasher. Granted the second set up is a tankless boiler running at 400,000 BTU but can handle the large demand of the restaurant.
     
  4. Redwood

    Redwood Master Plumber

    Joined:
    Dec 15, 2007
    Occupation:
    Service Plumber
    Location:
    Connecticut
    Laddy Boy's Credibility? [​IMG]
    Answer the Questions!
     
    Last edited: Feb 12, 2009
  5. Ladiesman271

    Ladiesman271 Homeowner

    Joined:
    Aug 22, 2008
    Occupation:
    Care and maintenance of transformers


    As a follow up to that question, I measured everything with that scenario.

    1. Typical water temperature that I prefer was measured at 105 degrees. No surprise there.

    2. Incoming water temperature is around 42 degrees (winter low).

    3. Incoming water pressure with nothing turned on is 71 psi.

    4. Tankless heater is an older Aguastar gas tankless with 125,000 BTU maximum.

    5. Thermostat set to 120 degrees nominal.

    6. 2.5 gpm flow shower head, standard old style three knob valve system.

    7. 1.0 gpm maximum flow from kitchen fixture.

    8. Normal shower setting (105 degrees) would be about 1/3 cold mixed with 2/3 hot with winter incoming water temperature (42 degrees).

    9. Fixed 3.5 gpm flow restrictor was not removed from tankless heater.



    I did perform a hot water capacity test in the manner that you described.

    1. Hot water in the shower set to full ON with no cold mixed in.

    2. Hot water in the kitchen sink set to full ON with no cold water mixed in.

    3. Ran water to cool down the tankless unit unit until a stable temperature was observed.

    4. Temperature of the hot water in shower and at the kitchen sink went down to 98 degrees and stayed there.
     
  6. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Joined:
    Nov 20, 2008
    Occupation:
    Chicago Illinois Licensed Plumber
    Location:
    Chicago, IL
    sjsmithjr has made a post in anther thread https://terrylove.com/forums/showpost.php?p=184390&postcount=78 that made me do some more research in the Illinois plumbing code.

    The Illinois plumbing code does not address the proper sizing of a tankless water heater directly like Florida does. But there are a couple parts that do help determine the proper size. For showers the maximum temperature is 115 degrees. For kitchen sinks the minimum temperature is 120 degrees. So with that in the code it addresses that the tankless system must be properly sized, or designed to be able to deliver these temperatures. With this information I contacted an Inspector and he informed me that he has failed installations that do not deliver 120 degree water to the kitchen sink while other fixtures are running. So now I need to write a couple letters to a few people explaining to them that they ether have to install the second tankless unit or ensure they are using low flow devices on their shower and sinks to ensure their single unit can meet the code properly. As for future installs I will insist on properly sizing the system for the demand to meet the code.
     
Similar Threads: tankless-luke warm
Forum Title Date
Tankless Water Heater Forum Utica - Shower water turning lukewarm after 5 minutes Jan 17, 2020
Tankless Water Heater Forum Heat works fine Shower takes over 10 minutes to "warm up" Dec 1, 2016
Tankless Water Heater Forum shower Lukewarm/cold after tankless install Feb 24, 2013
Tankless Water Heater Forum Rinnai Tankless REU-V2520-EFU. Water isn't as warm as it used to be. Feb 7, 2013
Tankless Water Heater Forum Bosch 125BNG gas water heater-Luke Warm water Dec 6, 2011

Share This Page