Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

is condensate neutralization absolutely neccesary?

Usually less than 5.

Although neutralization is not mandatory in any municipality (yet), I suspect that as soon as the sewage authorities realize that they are treating unpaid for fluid, they will come up with some whacky formula to charge the consumer for treatment of the unmetered condensate, and knowing them as I do, they will also assess some BOD charge due to the acidity, even though the acidity is probably a moot point by the time it hits then next block due to dillution.

In my book, unless the home is brand new with all plastic drains and sewers and is connected to a city system, neutralization is mandatory.



  • condensate neutralization

    where i live they do not require the neutralization of condensate before dumping it into the city sanitary drainage system. but is it a good idea to do it when in older buildings with cast/copper drains? i know it's highly acidic, but in a real world setting how fast would it eat the drains away? are we talking months, years or decades?
  • Ted_9
    Ted_9 Member Posts: 1,718

    I know its not mandatory, but I recently make the decision to install them on all newly installed condensing boiler installs.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • mp1969
    mp1969 Member Posts: 226

    You are ahead of the learning curve, I believe they are mandatory in Europe especially in hi-tech Germany.

    Should not be hard to price up for an environmental friendly add on. Keep using them as it is probaly a matter of time before they are mandatory.

    MP 1969
  • Guy_6
    Guy_6 Member Posts: 450
    neutralize it

    Untreated condensate will perforate copper pipe in 5 months if untreated.
    A neutralizer is easy to make with a length of 1 1/4 pvc pipe and some marble or lime chips. Bush down the ends, and you have a simple package. Use threaded fittings if you want to go upscale for easier servicability.
  • Scott04
    Scott04 Member Posts: 69

    Probably a dumb question, but since we do very little with gas heating equipment, mostly all I see for condensing stuff is something put in by others. Most of the ones I have seen all run into condensate pumps and then are pumped into the septic pipe. My question is: Would putting the lime chips in the condensate pump work, or would it cause problems with the pump, or other issues?

    Just thought that if it could be done, it would be simple, cheap, and easy to maintain!

  • Brad White_139
    Brad White_139 Member Posts: 6
    I would not

    put chips directly in the sump of the condensate pump. I had the same idea then thought better of it. When the marble chips break down, they soften and become more round. What wears off is a bit of a slurry which I suspect would clog and wear the pump impeller (which is a high temperature plastic).

    What I am doing now is using a 1-1/2 x 3" drum trap with the cleanout facing up to load with chips. The inlet port is on the bottom side, rising like a small standpipe to effect a seal. The outlet is on the opposite side, high. This should leave any residue inside at the low point.

    The entire unit can be removed (Hydro-Sorb clamp to unistrut) for cleaning. I will post photos soon as part of the current Vitodens installation.
  • bucket

    here is a design made by clammy that i may appropriate. i am having a hard time ponying up the dough for the official viessmann one.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    I used that method

    including the high drain outflow tapping so the condensate sits in the bucket longer. However, after a year and a half, that bucket became as brittle as glass. It is not PVC (I hope!) but rather HDPE I think. Anyone know?

    I have never seen anything like it, how the plastic degraded so quickly, from pliable to brittle.
  • Ted_9
    Ted_9 Member Posts: 1,718

    I hear ya there. Although the Viessmann one is nice, I love the idea of making it low cost.

    Since I cant find marble chips anywhere, I am buying The Viessmann replacement pellets.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,693
    You don't need the corrosion

    coming to haunt you 5 years later when a HO or bldg needs to chop up and repipe sanitary and it is traced back to YOUR!!!!! boiler installation. I know its a pain, but why take the chance? Mad Dog

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • hdpe

    yes, most of those buckets are constucted of HDPE, good tip about the brittleness, may have to do your PVC option.

    i haven't found any marble chips either, i believe they're also called lime chips, i'm checking on availability at a local feed/hardware store, sounds like something they might have.
  • i know

    i was gonna do it anyways, i just needed some reassurance that it was definitely a good idea.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Marble Chips

    I got mine at HD in the garden department. I use the "fine" grade versus the coarse because it flows better into the chamber. About $3.00 a bag (20# I think if not more) and it should last for years. Nothing wrong with the nice granular Viessmann pellets though.
  • Rob_35
    Rob_35 Member Posts: 33
    got a picture?

    I think I see what you're describing, but a pic would be great. If you have a sec? Small size in particular is attractive.

    I was contemplating a small mesh bag with chips in the pump's sump. I don't produce a huge volume of condensate, am draining through all plastic to a concrete septic tank, but what I do produce I would like to treat.

  • Ted_9
    Ted_9 Member Posts: 1,718
    Marble chips

    Brad, what are they called? when i go to these places, they act like im from Mars or something.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Quick Sketch of Condensate Neutralizer

    Here it is, Rob. Thanks for the prompt. :)

    I would not do the mesh thing because the residue is sort of a pasty slurry with a gritty feel. If the mesh bag would hold it back it would clog.

    Now, how do we harness the hydrogen made in the process? Another idea I did not need.... :)
  • tom_49
    tom_49 Member Posts: 269


    Try Agway. They are lime chips.

  • Brad White_9
    Brad White_9 Member Posts: 2,440
    They also

    give you the Minimum Wage Stare and really bad technical advice too! Marble chips, maybe limestone chips that is all I get...

    You are fine.
  • Xc8p2dC_2
    Xc8p2dC_2 Member Posts: 150
    Same question

    But in a dedicated drywell, below grade, non sump=pump, but in an open cellar, still a need to neutralize>
  • CC.Rob
    CC.Rob Member Posts: 128

    Simple! Thanks! My boiler is on blocks with pump on the floor, so vertical space is an issue. But I think I can implement a similar design on the way to the pump.
  • Chris E
    Chris E Member Posts: 11
    marble chips

    How often would those marble chips need to be replaced? I built a neutralizer similar to the one that Brad posted. How do I know when they need to be replaced, or on average how long do they last? I know each installation is different. Thanks
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    Viessmann says

    that a charge of their pellets will usually last a year, maybe more. Naturally this depends on how often you are in condensing mode and how many pounds of chips you have to begin with.

    What I do like about the Viessmann unit is that it is transparent. You can see any dissolving.
  • Chris E
    Chris E Member Posts: 11
    Here is a pic

    Hi Brad,
    Here is a picture of what I built. As far as pounds of rocks in it I would guess it is about 5 pounds of marble chips. The pump kicks on about 1 to 2 times a day. The boiler is an Ultra 80 that has been in service for about 2 years. I have not changed the chips since then.
  • Al_19
    Al_19 Member Posts: 170

    I use these filters for my water treatment work. They are available with clear sumps, and they also have refillable cartridges. So you can open it, remove the cartridge and refill it, and reinstall it like changing a sediment filter. They also have a solid mounting bracket. Maybe they would be applicable to what you guys are doing. These are 10" sumps. I've never used the refillable cartridges, but my supplier tells me they are available clear also, so you could see the level of the marble chips.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    How cool is that!

    Nice to see it in action before mine! Load it up every five years, why not? Thanks for sharing, Chris....

    I have another I just made, not unlike yours but it is horizontal, no reason it could not be made vertical except for the height restriction. Simple is good!

  • singh
    singh Member Posts: 866
  • Al_19
    Al_19 Member Posts: 170

    The filters are made of polypropolene. O-rings are EPDM. They're rated 125* F, 125 psi. They are also available with 20" sumps. So the refillable cartridge would be either 4-1/2" x 10", or 4-1/2" x 20". The Blue's are available in 1" and 1-1/2" inlet/outlet. The Clear's come in 1" only.

    Here's a picture of the 20" filter, and a better view of the mounting bracket.
  • Ted_9
    Ted_9 Member Posts: 1,718

    Here's one I made awhile ago. We are starting up the system next week. I hope that trap holds.

    The 3/4 on the left is from a GB142 and the 3/4 going into the standpipe is from the a/c.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Al_19
    Al_19 Member Posts: 170


    I don't know what kind of drip/flow rate that these things see, but it would seem that the inlet and outlet should be further apart to give the condensate more contact time with the marble media. I think you lose a lot with the horizontal setup. The vertical PVC ones, or the bucket one shown in the other posts look like they're set up to exit high so as to have to fill the unit to drain.
  • what i did in shop today

    van in the garage today, so i had a shop office day. design inspired by the viessmann one but 1/10th the price! still can't find anything to fill it with though...
  • what i did in shop today

    van in the garage today, so i had a shop/office day. design inspired by the viessmann one for 1/10th the price! used a 4" straight sewer tee with end c/o on branch and caps on ends with holes drilled to accept 1-1/2" X 1" bushings which are glued in. now to find something to put in it!
  • airman
    airman Member Posts: 10

    The code requirement to neutralize acidic condensate has been in the code all this time. In the NSPC it can be found in Special Wastes, Section 9.4, in sub-section 9.4.1 Treatment of Corrosive Wastes . Try looking in the manufacturer's installation instructions, or if silent, call them up. All high-efficiency condensing category IV appliances as well as some mid-efficiency appliances create corrosive condensate that must be neutralized. Another place to look for this would be in the 03 International Mechanical Code Section 307 Condensate Disposal which refers you right back to the manufacturer but does still tell you it needs to go to "an approved plumbing fixture", and that the piping shall also be of corrosion-resistant material. The only "approved" fixture I can think of would be that of an "active" laundry sink (one where a clothes washer discharges indirectly) , or a clothes washing machine stand-pipe box because the ph normally associated with the detergents being used for washing clothes would for the most part neutralize the acidity. They also do make condensate pumps that already have the neutralizer built in, although I really like the examples of the field fabricated ones I've seen posted here and can't find any relevant standard (other than the manufacturer's requirement) that would prohibit there continued or future use.

    Robert O'Connor/NJ
  • D107
    D107 Member Posts: 1,849
    Al what's the brand/co. on those?

    look real nice.
  • Patchogue Phil_29
    Patchogue Phil_29 Member Posts: 121
    Condensate from scorched air system

    Is the exhaust condensate from a scorched air natural gas system corrosive?

    One of my bro's has a new scorched air natural gas system, Trane I think. It's one of their newer VERY high effiency systems with 2" PVC exhaust that runs out the rimjoist and dumps into a flower bed maybe 2 feet from foundation.
  • Tombig_2
    Tombig_2 Member Posts: 231

    Flue gas condensate from a furnace is the same as from a boiler. The neutralizer is installed on the drain line from the heat exchanger, which goes down the drain, not the exhaust pipe which terminates outside. Drips from that pipe are also acidic.
  • scott w.
    scott w. Member Posts: 207
    cast iron drains

    Have a condensing boiler installed two years ago which dumps into the cast iron drain pipe in the basement. Does this mean i will be digging up the concrete floor to replace the 80 year old cast iron waste line anytime soon?

  • Al_19
    Al_19 Member Posts: 170



    These, or very similar filters are sold under several brands---Pentek, Ametek, American Plumber...---.

    Water treatment equipment manufacturers have done a lot of consolidating, and also do a lot of private labeling. But they are not always consistant in that Pentek may manufacture all of them, but different features(such as the clear sump, or 1-1/2" in/out) may only be available under certain names. So, although any plumbing supply or well pump supply will have filters, they may only handle a certain line and so not have all the options. Best bet is a water treatment supplier. They handle many different brands and individual components.

    I e-mailed you a contact if you're interested.

This discussion has been closed.