Thermal Expansion Tanks

Discussion in 'Water Heater Forum, Tanks' started by kcplumber, Sep 24, 2013.

  1. kcplumber

    kcplumber Master Plumber

    Messages:
    10
    Location:
    Overland Park, KS
    I install expansion tanks on almost every water heater I put in. Even if there is no PRV I still recommend installing the expansion tank.

    Sometimes, I feel like the customer is not buying into the idea of the expansion tank and thinks I'm just trying to sell them on things they don't need.

    "My last water heater lasted for 20+ years and did just fine without an expansion tank" is the most difficult type of statement to rebuttal.

    I usually tell them that water heaters are not built like they were in the past and that also the city water supply can be tougher on water heaters than in the past. I also let them know that it's code for many applications.

    Looking to get some feedback from other professional plumbing contractors and their thoughts on Thermal Expansion Tanks.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,242
    Location:
    Cave Creek, Arizona
    quote; Sometimes, I feel like the customer is not buying into the idea of the expansion tank and thinks I'm just trying to sell them on things they don't need.

    That is EXACTLY what you are doing. An expansion tank has absolutely NO function unless the heater is in a closed system, and even then, if the house was an a well the storage tank would act as an expansion tank.

    quote; I usually tell them that water heaters are not built like they were in the past and that also the city water supply can be tougher on water heaters than in the past.

    That is either trying to dazzle them with your brilliance, or baffle them with B.S., but either way it has nothing to do with the need for an expansion tank.
    Last edited: Sep 25, 2013
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,313
    Location:
    New England
    The code where I live requires an expansion tank...they changed this some time ago, so people that didn't have one, now are required to add one on a WH replacement, and the resistance is sometimes tough. Many places, when they do their periodic maintenance (and this may be a LONG cycle of many years), are replacing their metered supplies with those containing checkvalves. This is a system safety feature. So, in prep for this likely eventual situation, my city requires an expansion tank for a permit and inspection when installing/replacing a WH.

    Other than that, technically, if the system remains open, it is an extra bit except where required by code.
  4. kcplumber

    kcplumber Master Plumber

    Messages:
    10
    Location:
    Overland Park, KS
    Almost all of the homes in my service area have Pressure Reducing Valves, which as you know creates a closed loop system.
  5. kcplumber

    kcplumber Master Plumber

    Messages:
    10
    Location:
    Overland Park, KS
    It's also a code requirement for most areas that I service. I'm not trying to dazzle or baffle, just trying to provide quality service.
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