(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 9 of 9

Thread: How to CHange Water Temp on an Indirect Water Heater

Hybrid View

  1. #1
    DIY Junior Member
    Join Date
    Jan 2010
    Location
    New York
    Posts
    4

    Default How to CHange Water Temp on an Indirect Water Heater

    I have a Munchkin Boiler with a Vision controller. It has an Indirect Bradford White Water heater. The hot water temp coming from the hot water heater is 127 degrees. I would like to lower it to around 120 degress. I'm comfortable working with the controller. How do I lower the hot water temp?

  2. #2
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    Somewhere on the side of the thing tyically 1/3-1/2 the distance up from the floor is an adjustable aquastat that is wired to your zone controller. You may have to pull the cover to adjust it, but most have a cutout in the housing to be able to read the setting. Wiith oil or gas cast iron boilers it's common to set them to 130-140F to avoid condensation in the boiler, but with the condensing Munchkin setting it lower results in higher combustion efficiency.

  3. #3
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,405

    Default

    On my indirect, the setting is all done on the controller, there is no adjustable aquastat on the indirect, only a sensor that feeds into the boiler telling it what the temperature currently is. So, you'd have to read the Vision controller card's instructions to vary it, if that is even possible (I'd expect it is). If you have an adjustable aquastat in the indirect, it should be straightforward, otherwise, it may not be.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  4. #4
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    In a quick scan of manuals online, most Vision controllers have the option of using either the indirect's aquatstat or a seperate sensor, but it shouldn't be too tough to re-configure it if it's otherwise not programmable. All Bradford White indirects are fitted with aquastats. The default DHW temps on the Vision 2 (which was purpose-designed to work with Munchkin boilers, and thus the most likely version in use here ) if utilizing it's thermistor sensor is 119F, with 8 F of hysteresis.

    The instructions fro programming it to a different temp are on p.13:

    http://www.htproducts.com/literature/lp-118.pdf


    See notes 8 & 9 p. 24 if you prefer aquastat control instead.

  5. #5
    DIY Junior Member
    Join Date
    Jan 2010
    Location
    New York
    Posts
    4

    Default

    Thanks for trhe info!! .. I checked the settings the de DHW setpoint is set at 106 (Default is suppose to be 119), The dh DHW Differential is set at 10 (Default is 8). I'm getting 127 degree water with a meter at the hot water heater (Attaching to the pipe). Should I lower the 106 setting? I changed the differential setting to 8.

  6. #6
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    It sounds like either thermistor sensor or the control board is way out of calibration if you're getting 127F water with a 106F setpoint. You can lower the programmed setpoint to where the tanks output is at the temp you like, but check for bad connections on the sensor wiring first. If it's a simple mis-calibration issue it may still control it fine. If it doesn't do the trick you may need to do a deeper diagnostic.

Bookmarks

Posting Permissions

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