Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: Heater should not fire with no flow, right?

  1. Back To Top    #1

    Join Date
    Mar 2015
    Location
    Harvey, LA
    Posts
    300

    Heater should not fire with no flow, right?

    I just had a new raypak 400k cupro-nickel natural gas heater installed to replace my old Laars unit...the old heater would not fire if there was not flow through the heater. This new heater seems to not care if there is flow or not; when the heater was installed, I had the installer put in a couple of valves so I could isolate the heater when I need to lower pH for AA treatments, and when I isolate the heater, it will still fire when I expected it to error out due to no flow. Does this heater behave differently by design, or is something wrong preventing the flow sensor from stopping the heater from igniting?
    17.4k gallon IG pool with attached spa (spa itself is 730gal), Super Blue Diamondbrite plaster, Circupool SI-45+ SWG, BH/Hayward Cartridge Filter, 2hp 2speed Hayward Super II pump, , Jandy Valves, Waterway Skimmers, Rheem 400k Heater, Polaris 360 cleaner, built 2000+-, replastered June 2015, TF-100 kit---Here's my pool test reading history

  2. Back To Top    #2

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,434

    Re: Heater should not fire with no flow, right?

    That heater should NOT fire if there is no water flow. Now, if you isolate the unit and don't drain the water out of the header there is enough pressure inside it that it would fire. So when you isolate the heater with the two valves, drain the water out of the header and then it won't fire.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

  3. Back To Top    #3

    Join Date
    Mar 2015
    Location
    Harvey, LA
    Posts
    300

    Re: Heater should not fire with no flow, right?

    Ah...ok, that must be it, I didn't drain the header (and won't in this case, since I'm only doing it temporarily)...thanks!
    17.4k gallon IG pool with attached spa (spa itself is 730gal), Super Blue Diamondbrite plaster, Circupool SI-45+ SWG, BH/Hayward Cartridge Filter, 2hp 2speed Hayward Super II pump, , Jandy Valves, Waterway Skimmers, Rheem 400k Heater, Polaris 360 cleaner, built 2000+-, replastered June 2015, TF-100 kit---Here's my pool test reading history

  4. Back To Top    #4
    wjr75's Avatar
    Join Date
    Jun 2013
    Location
    IL
    Posts
    816

    Re: Heater should not fire with no flow, right?

    If I remember right there is a setting for the flow shutoff when you set it up. I remember reading about it in the manual but when I shut the flow off my heater turned off so I didn't have to mess with it.
    Inground 22k gallon gunite 15x31 main pool, 15x7 wading pool/sunning deck, hot tub/with overflow (9' octagon with limestone top) & slide NSWG, Aqua Blue Pebble Sheen
    Filter dual cartridge Sta-rite 450sq/ft, TF-100 Test Kit
    Heater Raypak 2100 400k btu cupro-nickel exchanger
    Auto pool cover, Polaris 280 auto pool cleaner, Jandy AqualinkRS8 Remote Control System

  5. Back To Top    #5

    Re: Heater should not fire with no flow, right?

    Note that heaters don't have a flow detection ability. They detect pressure. Therefore, they can fire with no flow as long as there's pressure.

  6. Back To Top    #6

    In the Industry

    ps0303's Avatar
    Join Date
    Jul 2011
    Location
    FL
    Posts
    3,434

    Re: Heater should not fire with no flow, right?

    Your higher priced commercial units do have flow switches.
    Paul
    http://www.gastekservices.com A word of caution: When working with gas and electrical you might want to consider a licensed contractor. Consider the value of your life and others around you. If you would like to provide a review of the help I provided, please use the following link to leave a review. gastek - Google Search,

  7. Back To Top    #7

    Re: Heater should not fire with no flow, right?

    I think that all heaters should come with flow switches. If swgs can include them, heaters should be able to as well.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •