Question to the homeowners out there

Discussion in 'Hangar Talk' started by vkhosid, Mar 6, 2017.

  1. vkhosid

    vkhosid Cleared for Takeoff

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    Hey guys,

    I've got a bit of a question for you. I just moved into a house a few weeks ago that was constructed less than one year ago. Although the house (overall) is fine, my gripe is with the hot water. In an effort to save a buck, the developer put in a tankless water heater at one end (of a long, skinny floor plan), and didn't put in a hot water return loop for a re-circ system. Now, when turning on the water in the master shower, it takes roughly 5-6 minutes for hot water to reach the fixture. I've settled on installing a re-circ pump with a cross-over at the furthest fixtures, but that's where I've hit a roadblock. Ideally, I'd like a re-circ pump with an aquastat that keeps track of the water temp at the farthest point in the line, and kicks on when the temp falls below a certain temp. However, I've only seen pumps that are demand-controlled, and require you to turn on a (any) fixture for a moment to get the process started. The other option I've found would be a "timer" re-circ pump. But, I haven't seen any that are compatible with tankless water heaters.

    To throw a wrench into this, the way the plumbing is layed out, I have two fixtures that could qualify as "the furthest fixture"....the master bath and the kitchen sink. If any of you know of a re-circ pump that would accommodate two senors (one in the master bath, and the other in the kitchen) that would be ideal.

    Thanks in advance for the suggestions.
     
  2. mscard88

    mscard88 Touchdown! Greaser!

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    Being that it is new, I suggest having the builder resolve the problem to your satisfaction.
     
  3. paflyer

    paflyer Final Approach

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    Or just replace the feed with 1" pipe and insulate it. Run the tub for 10 sec to get the flow at max.
     
  4. vkhosid

    vkhosid Cleared for Takeoff

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    The issue is that there isn't a "problem".....there's no requirement for a hot water return line to be built into the design...it's certainly a good idea, but not a requirement. So, the house is built to code...the 5 minute wait time is an "inconvenience". Though I am working with the builder. I'm trying to give some options of possible solutions without having to tear down the walls to add in a return line.

    That wouldn't be a practical solution, as the sheetrock would have to be removed to replace the pipework.
     
  5. Anthony

    Anthony Touchdown! Greaser!

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    Have you considered relocating the tankless water heater closer to the master bathroom?
     
  6. Zeldman

    Zeldman Touchdown! Greaser!

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    Wow... you have an indoor outhouse..???? You must be a rich pilot......;)
     
  7. vkhosid

    vkhosid Cleared for Takeoff

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    That wouldn't make much sense either because I'd have to run the gas piping to supply the water heater wherever I put it...which will require tearing down walls.


    The outhouse is outside....I prefer to wash my hands indoors, like a gentleman!
     
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  8. RV10flyer

    RV10flyer Pattern Altitude

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    Tankless wh and recirculating lines do not go together...unless you want $1000 electric bill. Either put a standard 50-80 gal wh and recirculating line on a timer or add another tankless on opposite end. Add additional insulation to tank and 3/4" thick armaflex to all hot water lines The builder should have put two in.
     
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  9. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser! PoA Supporter

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    I have had for 20 years, a recirc pump running continuously at my 1800sf home.
    I would do that again; forget the timer/temp controller.
    I would be ready to ditch the on demand water heater too.
     
  10. Shawn

    Shawn En-Route

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    You are also limited to the volume of water your low flow shower head can run for the hot water to catch up (hence your 5-6 min lag). Although it is a complete waste of water and does not really solve your issue...you can run both the bath which is not throttled and sink both at full hot which will speed up the flow of the hot water to the shower head from the water heater.

    I have to do that in hotels all the time.
     
  11. luvflyin

    luvflyin Final Approach PoA Supporter

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    I dont know nuthin about recirc pumps so I cant help you there. Poor design but I guess you're stuck with it. 5-6 minutes seems to long. Are you running it through the shower head? Those things are all pretty low flow. If its a tub also, run it through the tub tap until it warms up. Try the head on its maximum flow rate and then adjust it down when it gets warm. Open the hot water tap on the lavatory sink until it warms up.

    Or just get a Kramer
     
  12. weilke

    weilke Touchdown! Greaser!

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    What would you circle it into if you use a recirc pump with a tankless water heater ?

    Isn't the idea of those things that you don't have a volume of water that has to be maintained at temperature and that they only kick in if they sense demand for hot water ?
     
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  13. Ventucky Red

    Ventucky Red Cleared for Takeoff

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    Probably has a cement pond too...
     
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  14. Chip Sylverne

    Chip Sylverne Final Approach

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    Fear is the poison of our lives.
    If you're looking for instant hot water for washing hands, face etc, how about a supplemental electric on-demand under the sink?
     
  15. NealRomeoGolf

    NealRomeoGolf Pattern Altitude

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    I hate tankless water heaters. That's all I have to add.
     
  16. coloradobluesky

    coloradobluesky En-Route Gone West

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    Do what most people do. Turn on the hot water, go to the bathroom, then wash your hands, shower or wash your hair.
     
  17. vkhosid

    vkhosid Cleared for Takeoff

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    They absolutely do. As a matter of fact, many manufacturers (such as Rinnai, Navien, etc) pre-wire/install re-circ pumps in most/all their models. You may be thinking that the re-circ pump runs constantly...that's not the case. There's a switch or timer that triggers the start/stop of the pump.

    Well, ideally with a hot-water return line, you'd push the water through the "return" line into the cold-water "in" connection at the tankless water heater. However, for instances where the re-circ pump is an "after-though", there's a cross-over at the last fixture which pushes the water back through the cold-water supply line back into the tankless water heater as well.
     
  18. vkhosid

    vkhosid Cleared for Takeoff

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    Regarding all the comments about the low-flow shower heads....yes, I've thought of that as well, but haven't yet had the chance to take off the shower head and remove the water metering device...(another issue is that the shower feels like a drizzle, instead of an actual shower).
     
  19. SoonerAviator

    SoonerAviator Final Approach

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    If you have the space, I'd consider putting in a small electric water heater under the sink or in a nearby closet. It would give you the short-term hot water until the tankless system reaches the bathroom.
     
  20. 455 Bravo Uniform

    455 Bravo Uniform En-Route

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    Are you absolutely sure that the heater kicks on the moment the water starts flowing?
     
  21. vkhosid

    vkhosid Cleared for Takeoff

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    100% sure this happens within a second or two.
     
  22. N747JB

    N747JB Final Approach

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    That's kind of what I was thinking, we put a recirculating system in our house when we built it, it's great, but the idea of tank less is they don't have a tank to send the water back to. :) But, I am no plumber!! :rolleyes:
     
  23. simtech

    simtech En-Route

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    I have a new construction home and we too have the tankless wh. Love it, it never runs cold...ever. Mine is by the master so the kitchen and the master bath gets its water pretty fast. However, the vanities in the master bath are slow to get hw. I mean slow and I think its because the flow is low on it. So if I crack the tub faucet and the vanity faucet I get hot water pretty quickly. Its a small price to pay to not have a tank. I love not have a tank that gets cold!

    And with that for those that ever followed my contractor thread, we moved in and LOVE our house...okay sorry for the thread drift.
     
  24. Dana

    Dana Pattern Altitude

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    I love the tankless heater in my cabin,I never have to worry about running out of hot water... but it's a small cabin so there's never much wait. In my house, I have a large tank heater at one end of the house, and a small electric heater in the master bathroom at the other end, no waiting.
     
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  25. Timbeck2

    Timbeck2 Final Approach

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    Freakin third world problem fer sure. ;) Reminds me of the meme with the little African kid looking at an American woman captioned:

    You mean to tell me that you have so much fresh water that you **** in it?
     
  26. RV10flyer

    RV10flyer Pattern Altitude

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    Well, if one is trying to maintain 120F water using a thermistor sensor, attached to a circuit board that turns pump on and off as well as heating elements, no thanks on the complexity and power consumption. I would rather just have my 80 gal tank or two 40 gal tanks(one on each end). As far as putting hot water back into cold, hopefully it cycles off before it fills my cold water line. Otherwise, I would have to run cold water to brush my teeth.

    I have many hvac customers and family that installed those tankless wh. They switched back due to expensive power bills and numerous breakdowns.
     
  27. paflyer

    paflyer Final Approach

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    Yep, that's what I suggested; have to do the same, since master bath is on 2nd floor on opposite side of the house, prob 85' of 3/4" pipe in between. If you run the shower or sink, the EPA-mandated flow control will take forever.
     
  28. vkhosid

    vkhosid Cleared for Takeoff

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    Standard practice is for gas-powered tankless water heaters for single family residences. At least in california.
     
  29. paflyer

    paflyer Final Approach

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    [​IMG]
     
  30. paflyer

    paflyer Final Approach

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    Well there you have it. Heh....
     
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  31. weilke

    weilke Touchdown! Greaser!

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    The tankless ones work well in a non-freezing place like FL where you can stick them on an outside wall right by the bathroom.
    I had one 20 years ago. Hated it.
     
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  32. RV10flyer

    RV10flyer Pattern Altitude

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    85' of 3/4" type m tubing holds about 2.3 gallons of water. Of course you need to heat all of that water line too.
     
  33. RV10flyer

    RV10flyer Pattern Altitude

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    We had a tankless gas wh in Germany from 89-91. I bet the plumber worked on it 10 times. High efficiency does not always equal saving money in the end. HVAC systems that I sell are similar. They save electricity while they are working. When they break down out of warranty, they can cost a small fortune to repair.
     
    Last edited: Mar 7, 2017
  34. paflyer

    paflyer Final Approach

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    Yep. I bought the house used, hence no say in where the equipment was installed.
     
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  35. paflyer

    paflyer Final Approach

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    But it made some people feel good to demand them as standard.
     
  36. vkhosid

    vkhosid Cleared for Takeoff

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    Perhaps...but i'm willing to bet that perhaps one or two things has changed technology-wise in the last THIRTY years? That's like saying, "I'm not buying a Ford this year because of their Pinto fiasco."
     
  37. RV10flyer

    RV10flyer Pattern Altitude

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    Good luck with whatever your choice. Let us know. Congrats on the new home.
     
  38. 172andyou

    172andyou Line Up and Wait

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    Yeah, exactly. Tankless is the greatest thing ever for us long-shower guys. It's funny that way. Tankless is a more efficient design, so should be an energy saver. But a significant portion of the time the only thing that gets me out of the shower is that I'm running out of hot water!
     
  39. RV10flyer

    RV10flyer Pattern Altitude

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    Here is a little video I found...

     
  40. RV10flyer

    RV10flyer Pattern Altitude

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    If you add a motherboard to something, it must be better. Right?