Thermal expansion tank

Discussion in 'Plumbing Building Code' started by Tamas, May 24, 2015.

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  1. May 24, 2015 #1

    Tamas

    Tamas

    Tamas

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    Hi
    Wht Do I need THermal exp. tank for my tankless water heater order by LA dbs
    plan checker

    Tanx
     
  2. May 24, 2015 #2

    Mr_David

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    Good Question! Tank less only heats water on demand when something is open and drawing water. Did you try asking them why they are requiring the tank.
     
  3. May 24, 2015 #3

    journeyman

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    i have never heard of an expansion tank on a tankless heater would love to know more and the reasoning behind it
     
  4. May 24, 2015 #4

    IFIXH20

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    Do you have a recir pump or using a small tank type water heater as a storage tank. If so, that could be the reason. I just had a pow wow with local inspectors about the hybrid water heater condensate drain. 3 out of 4 counties say its ok to plumb it to the exterior of the home like a a/c condensate drain but one county say plumb it to the house / building drain. The codes book we are using do not have anything on the hybrid water heaters so I am trying to get the last county to fall in line with the others.
     
  5. May 25, 2015 #5

    frodo

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    your code book will not call out a hybrid heater..you will find your answer under indirect drain connection
    or condensate drains


    a condensate drain can not hook up directly to your sewer system, it must drain indirectly. [air gap]

    this fact, can open up a can of worms..such as trap primer.

    it is best [cheaper] to run the condensate outside
     
    Last edited: May 25, 2015
  6. May 25, 2015 #6

    Mr_David

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    Thread Hijack in progress :cool:

    I had to go look it up because AC condensate lines can be connected directly to a fixture tail piece of which is contradictory to being an indirect connection,
    I know! The comment was in regards to a heater condensate drain.


    California code

    814.1 Condensate Disposal. Condensate from air washers, air-cooling coils, fuel-burning condensing appliances, the overflow from evaporative coolers, and similar water-supplied equipment or similar air-conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area. If discharged into the drainage system, equipment shall drain by means of an indirect waste pipe. The waste pipe shall have a slope of not less than one-eighth (1/8) inch per foot (10.4 mm/m) or 1 percent slope and shall be of approved corrosion-resistant material not smaller than the outlet size as required in Table 8-2 for air-cooling coils or condensing fuel-burning appliances, respectively. Condensate or wastewater shall not drain over a public way.

    814.3 Point of Discharge. Air-conditioning condensate waste pipes shall connect indirectly to the drainage system through an airgap or airbreak to a properly trapped and vented receptors dry wells, leach pits, or the tailpiece of plumbing fixtures.

    Condensate waste shall not drain over a public way.

    *******************************************

    814.3 seems to only address AC condensate of which can connect to a fixture tail piece which is not an indirect connection.

    All other types of condensate referred to in 814.1 " discharged to an approved plumbing fixture or disposal area. If discharged into the drainage system, equipment shall drain by means of an indirect waste pipe. "
     
  7. May 25, 2015 #7

    frodo

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    801.4 upc

    my book has the same thing yours does..801.0 same as yours

    look a little closer to 801.4 [couple paragraphs later] yours might address wh also

    scan0001.jpg
     
    Last edited: May 25, 2015
  8. May 25, 2015 #8

    frodo

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    :D:rolleyes::D:D:D:)
     
  9. May 25, 2015 #9

    Mr_David

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    But a Condensate drain is not connected to water system. A T&P relief valve is however. ;)
     
  10. May 25, 2015 #10

    frodo

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    what i read, spells out the drain and the pop off


    also a y branch tail piece is to small to use as a pan drain..min..is 3/4'..', y branch is 1/2'' correct?

    scan0001.jpg
     
    Last edited: May 25, 2015
  11. May 25, 2015 #11

    IFIXH20

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    We understand the indirect aspect . I see California UPC has something on w/h condensate drain. We are going off Florida 2010 IPC and don't have anything on it. The Head Inspector (in 1 county) tells me we do not have anything in our codes so plumb it to manufacturer spec. Manufacturer say plumb/run condensate drain to a floor drain, standpipe or laundry tray not taller than 3ft, Use a condensate pump if needed, or plumb to local codes. I have spoke with two manufacturers about plumb/running the condensate drain to the exterior of the home with a trap on the line, both Manufacturers said it would be ok. Have anyone else in Florida ran to this problem ?
     
  12. May 26, 2015 #12

    frodo

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    run it to exterior,,trap not needed
     
  13. May 26, 2015 #13

    phishfood

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    I have not run into a problem per se, though I have run the condensate drain for quite a few hybrid water heaters. I have always plumbed them consistent with an AC condensate drain, as that is really all that they are. There is no real cross connection hazard between the potable water system and any non potable piping system.

    One thing I can tell you, is to NEVER pipe the drain in CPVC. It seems that there is some petrochemical residue in the coils that will react with CPVC in a very unfavorable manner.
     
  14. May 26, 2015 #14

    IFIXH20

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    Thanks for the CPVC heads up Phishfood. I am talking to other plumbing contractors in the area to ban together and put pressure on them to allow us to pipe to the exterior of the home. 1 out of 4 neighboring counties wants to be a D.
    Thanks for the feedback guys.
     
  15. Jun 9, 2015 #15

    integrityplumbing1

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