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geraldtorres

Water softener on tankless intake only?

Gerald Torres
9 years ago

New construction, but we're just about done. Unfortunately, we had installed a tanked heater, but now the city is saying we must have a heater with EF 91+ and SCAQMD cert, which pretty much limits us to a condensing tankless. Thanks (city, architect, GC, and plumber) for not telling us earlier, #@!$! (The tanked heater has been on our initial plans since the beginning)

We've selected the Noritz NRC1111DVNG. Our SoCal water is hard (~18gpg): http://www.ci.manhattan-beach.ca.us/home/showdocument?id=11916

Looks like all the recommended anti-scale devices are questionable, so I've ruled them out. Heater will have isolator valves for flushing, but I'd really prefer to avoid that maintenance in favor of adding salt to a softener. The primary driver for soft water is protecting the heater, so I was thinking of just adding a "smaller" softener to just the heater intake vs a whole house solution. we won't have to worry about bib bypasses. If we set the heater at shower temp, then showers will effectively use only softened water, helping with glass enclosures and fixtures. Scale buildup at the washer hot water input was pretty bad when we disconnected it, but the cold side didn't have much at all. We already have an RO for drinking water, so I don't see much benefit in softening other cold sources.

Plumber will be adding a standpipe for the heaters condensate (~2gph max). He was planning just 1.5", but said he could upsize to 2", maybe more. I want to reuse it for the softener waste, but haven't scope the rates for particular units yet.
I thought it wouldn't be so hard to select a softener, but it seems one has to sift through a lot of the saltless junk to find good info. Since we just want to move in, we'll probably have the plumber stub the bypass loop on the intake, and I'll try to install it later, giving us time for due diligence. I am concerned about sizing the standpipe properly though.

3 showers, 2 tubs, 1 dishwasher, 1 clothes washer. Family of 4. Parents will move in when the time comes, probably when the kids hit the teens, although they already love 1hr+ showers when we're not paying attention. So guessing 5 showers x 1hr x 60min x 2.5gpm x 18gpg = 13.5k

Not sure about iron in water, but we do get brown deposits at the toilet outputs.

Any other things I need to research? Any particular brand recommendations, particularly local to Los Angeles? Or is it easy enough to DIY everything where I can just assemble the parts from any source? I'm not in any trades, but handy.

Comments (13)

  • justalurker
    9 years ago

    Only softening the hot side protects the water heater but you'll have real hard water at every cold faucet, appliance, and fixture.

    Feeding an RO 18gpg hard water will dramatically shorten the membrane service life.

    And "Not sure about iron in water, but we do get brown deposits at the toilet outputs" is another important consideration so you'd be well served to get a comprehensive water test from a certified lab and look to see what else is in your water that you ought to treat.

    The primary driver for soft water is longer service life from EVERY appliance, EVERY fixture, EVERY faucet, clothes last longer, you use less soap and detergent, Mamas hair is silkier and smoother, and there's the already mentioned RO membrane.

    IMO if you're paying for soft water you ought to get it.

  • Gerald Torres
    Original Author
    9 years ago

    I found the 2011 report which has some additional values not reported in the 2012 report above
    http://www.citymb.info/Home/ShowDocument?id=10037

    To clarify, water is 45% groundwater and 55% city, but it seems I should use the worst case values when sizing:

    hardness: 440ppm
    iron: 0.18ppm
    manganese: 0.88ppm
    TDS: 840 ppm
    pH: 7.6-8.6
    sulfate: 160ppm
    alkalinity: 220ppm
    nitrates: 2.2ppm
    turbidity: 2.3
    chlorine: 2.5ppm

    Will have to revise gpg from first post, and 150gpd/person (hot only) is probably too conservative.

  • Gerald Torres
    Original Author
    9 years ago

    Understood on the cold hard water. I'm not sure how we can bypass the backyard bibs since they're at the far end of the house from the garage where the softener and heater are. I'm sure we can bypass the first bib, and so just run a really long hose when tending to the garden. Will have to also check where the irrigation lines are coming from. We'll be thinking about it since the heater and bypass will be going in on Monday.

  • justalurker
    9 years ago

    You're already using the WORST case values when sizing. Is your intention to treat the water you had two or three years ago or the water you have now?

    Municipal water reports are always old and averaged not indicative of the water at your meter today.

    Water treatment is chemistry and physics with a little mechanics thrown in... disciplines that don't accept inaccurate data with any expectation of arriving at a correct answer.

    Approaching water treatment as an investment that pays off in savings for a long time is a smart move especially when building cause it's a lot easier to do it right then.

  • Gerald Torres
    Original Author
    9 years ago

    I hope to be able to treat what water we will get for the forseeable future. The city reports provided a range. I checked 2010 also, and the ranges seem relatively consistent over these years. Some of the ranges seem pretty wide though. Would a single sample at my house be better than their provided ranges? Would it be an accurate representation for any future given amount of time? It seems that I would have to take periodic samples to get an accurate representation.

    Below is where the heater will be going, on the right wall. The standpipe will be coming off that drain to the right of the door which would put it at least 5' above the floor, which may complicate positioning a softener. The drain is from a toilet upstairs. The heater must remain within 8' from the floor. It seems that to be able to utilize that corner, we should keep the heater away from the corner since any softener would likely need a stand to use the standpipe. Water comes in from that 1.25" PEX, and it does come in after the front bibs and sprinklers. Gas line is running in that soffit along the same wall and meter will be just outside this wall also.

  • justalurker
    9 years ago

    One treats the water conditions they have not what was. A comprehensive water test from a certified lab will tell a knowledgeable water treatment pro what is in the water that should be treated and then based on those test results, water usage, and plumbing considerations an informed decision on what treatment equipment is necessary and correct sizing can be made.

    Contemporary electronically controlled softeners make it easy to adjust for varying water conditions and usage to a point.

    The drain line from a softener can easily rise 8-10 feet to accommodate your standpipe, but remember, the standpipe has to have a P trap and the softener drain line must have an air gap at the stand pipe (check local plumbing codes) and the pipe must accommodate approximately 50 gallons from the softener during regeneration.

    Never a bad idea to retest water to make sure things haven't changed especially on a well. Municipal systems can and do vary but usually with some consistency as they draw from numerous water sources but the results are usually from the treatment location and not your water meter however many miles of pipes and valves away you might be.

  • Bruce in Northern Virginia
    9 years ago

    When they do the rough in for a water softener they often build a raised area that is big enough for the softener and the water heater next to each other; but it doesn't look like they left you that much space. However, since the tankless is usually wall mounted, I would think you have enough space to put the softener on the raised platform and the tankless heater mounted on the wall. Is there a drain pipe in the wall right behind the water heater area that you can use when back-washing the softener?

    A couple other questions, based on situations I've run into.

    Is the existing gas line on the lower left sized large enough for the tankless heater? There might be a big enough line running through the ceiling, but the connection at the water heater might be smaller.

    Are you required to enclose your gas water heater in a cabinet? In my house they had to go back after the fact and enclose the gas water heater area and install the proper venting (high and low vent points in the cabinet) because it was in a garage. This took some space away from the water heater and softener area.

    Bruce

  • Gerald Torres
    Original Author
    9 years ago

    Will be looking for someone to do a water test. Is there some kind of standard named test to be done, or is it a matter of identifying each parameter a la carte?

    The old water heater location to the left of the door can't be used because there is no drain available there. The heater will be wall mounted (right wall) about 12" away from the corner due to venting clearances from door, outside corner, eaves, gas meter, etc. We weren't originally planning on a softener so there was no space allotted for it in the original location. Also, that door wasn't supposed to be there originally and was planned to be on the wall to the right, and at slab level (another long story). So now, we have 16" between the steps and the wall to see if we can fit a softener. Otherwise, it'll have to encroach towards the parkable area. Luckily, we have about another 3' before the restricted zone.

    The gas line on the lower left will be removed. I forgot to ask him about whether he'll be teeing off the existing gas line at the ceiling or just running a separate line to the meter since it's very close behind that wall. It came up as an option to avoid recalculating loads. Also, the recirculation stub down by the platform will be removed and moved over to the other wall as well.

    I haven't found or heard anything about enclosing the heater. It will have in and out vents, spaced 2' apart, directly out the wall. Well, the output will turn right for 2' first, then go out. Due to the height, we weren't required to have vehicle protection. The plumber had reviewed the current plan with the city already, so hopefully no new surprises with this setup.

    Also, due to the planned position of the heater, it will be tight for him to tee off for a whole house bypass at the current location. We're going to have to deal with the softener rework later then since we just want this part done as quickly as possible to get in already, and we don't want to add costs to this work to complicate the responsibility since we want the architect and/or gc to be covering the cost of the current rework.

    BTW, the standpipe will tee right above that bend and he had the iron(?) tee and trap and it looked to be 4", but he said that a separate vent would not be needed and was ok'd by the city.

  • p4badsha
    9 years ago

    gbtower did you figure out what lab you were going to use to test your water? I live in El Camino Village, which is approximately 7 miles from you. I would be interested to know the cost and lab you chose. I am also in the process of specing a water softener system.

  • Gerald Torres
    Original Author
    9 years ago

    Not yet, but will likely check at least the following 2 places that are used by our city.

    Truesdail Laboratories Inc.
    Tustin, CA
    (714) 730-6239

    Clinical Laboratory of San Bernardino Inc.
    San Bernardino, CA
    (909) 825-7693

  • p4badsha
    9 years ago

    Got a quote from Clinical Laboratory of San Bernardino Inc. Does this forum have private messaging?

  • Gerald Torres
    Original Author
    9 years ago

    I had sent out feeler emails earlier to a couple places, and they've been the only response I've gotten so far. I've been only generally inquiring about drinking water tests, without a specific list of tests, so didn't get any quote.

    @badsha, I just turned on emailing on my profile, so I you should be able to msg me now.

  • p4badsha
    9 years ago

    Great. I just emailed you what I found out. I also posted Water Softener help spec thread if you have any insight.