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Evaporator and furnace condensate drain, pH neutralizer needed?

jc2464jc2464 Posts: 6Member
Hello! I have a Bryant 915SA high-efficiency furnace with a Bryant CNPHP AC evaporator unit. Both the AC evaporator and furnace condensate drains were going into a single PVC pipe, then into a 'pH Treat' acid neutralizer, then into the sewage line.

The pH neutralizer is vertical-mount only, and was wrongly installed horizontally. It thus clogged up, backed water into the furnace and evaporator, and generally flooded the attic. As a temporary solution I removed it entirely and bypassed it with a flex tube, so now both the furnace and evaporator drain directly into the sewage (each still having a trap).
  1. Does this setup even need a pH neutralizer for the furnace? I can't find any reference to this requirement in the installation manual and my city's sewage code.
  2. Shouldn't the AC evaporator drain bypass any pH neutralizer anyway?
  3. While on this topic, why doesn't my high-efficiency tankless gas water heater have a neutralizer for its condensate line?
Thanks for reading, and appreciate any thoughts you may have!

Comments

  • JUGHNEJUGHNE Posts: 5,859Member
    IMO, the main concern is your house drain piping. If it is all PVC, no problem. If copper or cast iron the acidic condensate can slowly eat away that material.
    I have a small trough etched in my concrete where my boiler drain hose did not quite get to the PVC floor drain.
  • HVACNUTHVACNUT Posts: 2,410Member
    Yes, replace the neutralizer.
    No, the evap drain does not need to go through the neutralizer but it wont hurt.
    How did a contractor, in 2019, install a condensing furnace and A/C in an attic and not install an emergency pan and wet switch? Ludicrous.
  • Jamie HallJamie Hall Posts: 10,852Member
    Your city's sewage code probably does not have a specific reference to condensate drain waste. It almost certainly has a reference to hazardous waste, however, and condensate drain waste is a hazardous waste until it has been neutralized. I very much doubt that anyone will come by to inspect and enforce that on its own, but it could be picked up in some other inspection -- and the penalties for hazardous waste discharge can be draconian, even in de minimis situations.
    Jamie

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • jc2464jc2464 Posts: 6Member
    edited July 23
    Thanks all for the replies! I'll get a horizontal-orientation pH neutralizer before winter. As far as I can tell the drains are all PVC, but it sounds like installing a neutralizer is for the best. As long as the huge volume of AC evaporator water doesn't 'use up' the base, it'll be easiest to continue using the merged pipe.

    As to how this happened... It's a long story, but involves a local house flipping company in late 2017 being stretched too thin and not really knowing what they were doing, while failing repeatedly to get a occupancy certificate from the city. As my downstairs neighbor put it, their subcontractors had subcontractors...

    There actually is a pan and switch, which remained perfectly dry as the backed-up water from the clogged pH neutralizer exited through the air outflow duct just outside of the pan.
  • HVACNUTHVACNUT Posts: 2,410Member
    > @jc2464 said:
    > As my downstairs neighbor put it, their subcontractors had subcontractors...
    >
    That's pretty funny.

    > There actually is a pan and switch, which remained perfectly dry as the backed-up water from the clogged pH neutralizer exited through the air outflow duct just outside of the pan.

    The water came out of the duct, where the plenum attaches to the evaporator? Does the emergency pan cover the entire area under the furnace and evaporator?
    Is there a drain for the emergency pan?
  • jc2464jc2464 Posts: 6Member
    > Does the emergency pan cover the entire area under the furnace and evaporator?

    Yes, it seems to cover the machines quite well. All the water leaked further out where the plenum split into two ducts, about two feet out--I guess the tape was more watertight where it attaches to the evaporator.

    > Is there a drain for the emergency pan?
    Nope! It does have a shut-off switch though if it ever fills up, it would make for a fun siphoning operation.
  • HVACNUTHVACNUT Posts: 2,410Member
    edited July 26
    Is there a trap for the A/C drain? Is the trap clear? Is the insulation on the bottom of the blower compartment wet? Is the A/H level both ways? No pitch. The pan inside is already pitched.
    It seems as if the fan is pulling condensate right off the evap and throwing it down supply plenum.
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