Reuben's Home Inspection Blog

Hot Water Faster

May 29th, 2012 | 19 comments

HourglassDo you ever get annoyed with how long it takes to get hot water at your kitchen sink?  I do did, up until last weekend.  It used to take a full 45 seconds with the hot water turned on full blast before I would actually get hot water my kitchen faucet.   With my kitchen faucet rated at 2.2 gallons per minute, that would equal a little over 1 1/2 gallons of wasted water every time I needed hot water at the sink.

I’ve considered a few different options to get hot water at my kitchen sink faster, such as installing a re-circulating pump or a point-of-use water heater – you can read about the details of these options at Home Depot’s web site.   I decided against these options because the installation would take too much time, and the materials alone would cost more than I was willing to spend.  Thanks to an idea I read about in The Journal of Light Construction, I was able to significantly reduce the amount of time it takes to get hot water at my kitchen faucet, and the total cost of materials for this project was less than $40.

All I did was install a dedicated 3/8″ water supply line from the water piping coming off the top of my water heater to the kitchen sink faucet.  By installing this 3/8″ water line, I’ve cut the wait time from 45 seconds down to 10 seconds.   Part of the reason I get hot water so much faster is that the hot water doesn’t need to fill up all of the main ‘branch’ lines to get to my kitchen faucet.  The hot water line that feeds my kitchen sink consists of 17′ of 3/4″ tubing, then another 25′ of 1/2″ tubing.   I’ve cut the total run down to about 25′ by running the line straight to my faucet.  The other reason this works is because a 3/8″ tube has about 25% of the volume as a 3/4″ tube.

You might think that this reduction in size would equate to lower water flow at the kitchen faucet, but it actually made no noticeable difference.  The hot and cold water flow both seem to be identical.   So what’s the downside to this, and why don’t more plumbers do this?  It’s a code violation.  The Minnesota State Plumbing Code requires a minimum of 1/2″ pipe to the kitchen sink.  Because of this, I left the old 1/2″ water line in place.  When it comes time for me to sell my house, I’ll probably just re-connect the old 1/2″ water line to the faucet.  It should take about 30 seconds.

Reuben Saltzman, Structure Tech Home Inspections – Email – Minnesota Home Inspections

        

19 responses to “Hot Water Faster”

  1. Reuben
    May 29, 2012, 8:18 am

    I’d love to see some pics.

  2. Reuben Saltzman
    May 29, 2012, 7:16 pm

    I just uploaded two pics – http://www.structuretech1.com/wp-content/uploads/2012/05/Tee-for-smaller-copper-line.jpg and http://www.structuretech1.com/wp-content/uploads/2012/05/Feed-to-sink.jpg

  3. Bill
    May 30, 2012, 6:52 am

    I am surprised that a home inspector is admitting to having installed plumbing that violates the law “until they want to sell the house”.

    I understand somone doing this but I am assuming that you could be charged with a violation of the law.

    I know of an instance (beause of previous posts of yours) where some very useful remodeling was done but may (depending if the law was in effect) violate a part of the law that would only be known to professionals like you. I have considered if the house is sold that the owner might have to undo the work (a minor job) but that they would put the parts in the garage and tell the new owner that they were removed due to violation of the law but they could do with it what they want.
    However, I am not a licensed professional and would not even claim to play one on TV.

  4. BigguyZ
    May 31, 2012, 12:44 pm

    Bill- Violation of code and violation of the law are different things….

    Reuben’s fix makes sense to me, and when it comes to plumbing codes there are a lot of thjings that don’t make any sense.

    For instance, hose bibs. MN code requires a 3/4″ line. If you look at the newer wall hydrants with PEX fittings, you’ll only find 1/2″. Why? Because 1/2″ is fine to supply the amount of water needed.

    Also, if you look at PEX manufacturer’s reccomendations for a home run system (which is all I do when I am allowed to do plumbing work), many reccomend using 3/8″ lines to the individual fixtures. Maybe a shower would be different, but I’d say that’s the case only when you’ve removed that dang low-flow disc that plugs up your shower head (another violation)!

    Otherwise, consider this: the union fitting that connects your water meter to your supply system is a 1/2″ fitting. So from the root of your system, you have a limiting factor there. Additionally, with all of the low-flow faucets today, the flow is again limited at the faucet. So the size of the pipe leading to that has little effect on the resulting pressure/ flow to the faucet.

    I’d love to see 3/8″ PEX and fittings to be more available, and for code to allow more sensible building.

    I’m not a plumber, nor an inspector, just an avid remodeler and an individual working on my brother’s house (with permits/ inspections- all passed).

  5. Mark Franklin
    June 7, 2012, 4:25 pm

    This option will only work in a limited number of homes. Another approach is the WaterQuick Pro II.

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  12. Bird Proofing
    July 31, 2012, 1:57 am

    The cost of maintenance goes up especially if the materials used during its construction are of substandard quality. To get your home run at a lower maintenance cost is to use construction materials, plumbing and wiring of the best quality possible. And having a timeframe for maintenance and check up to avoid from expensive repairs.

  13. Melvin Bell
    October 26, 2012, 6:31 pm

    What do you do if you are renting the property and have the same hot water problem?

  14. Reuben Saltzman
    October 26, 2012, 7:11 pm

    I think you just have to wait.

  15. ArtND76
    November 18, 2012, 6:03 pm

    Rather than an electric pump, does anybody market a simple jet pump to perform the recirculation whenever any hot water is turned on? If it amplifies the 2 GPM flow out of the faucet to a recirculating flow of 10 GPM or higher, wouldn’t that be a “nearly as good” solution that is a LOT cheaper and simpler to install?

  16. JonV
    January 6, 2013, 12:06 pm

    If you have the 3/8″ line already run to the kitchen, why not create a “gravity loop”?

    Instead of connecting the 3/8″ line to the TOP of the water heater, connect it to the hot water drain at the bottom (for my system I replaced the factory drain with a 3/4 nipple going to a Tee – the bottom of the tee connects to a 1/4 turn cutt-off – the top of the tee is the gravity loop “return”).

    Below the kitchen sink tie-in the 3/8 to the 1/2 using a tee.

    Insulate all the piping so as to minimize energy loss.

    The best part is that if done right the system will meet code (though you might be required to run a 1/2 return line – instead of 3/8″).

    There are a few more details – like removing the anti-convectioning flappers at the top of the water heater; additionally a check-valve could be installed on the return line. Google is your friend…

  17. Reuben Saltzman
    January 6, 2013, 8:42 pm

    Not a bad idea. I might have to try that.

  18. Roxanne Amerson
    April 2, 2013, 6:40 pm

    We bought a house last summer. It takes 1 1/2 minutes of letting the hot water run full blast to actually get hot water at the kitchen sink. The builder said they ran the hot water upstairs to the master bedroom first and the kitchen is at the end of the water line, so that’s why it takes so long. He said this was a normal thing to do, but it just does not seem right. I waste a lot of water waiting on the hot water, not to mention, it probably affects how my dishwasher works. Does anybody know if this type of installation is against code? I live in SC.

  19. Reuben Saltzman
    April 2, 2013, 7:20 pm

    As far as I know, there is nothing in the code that prohibits that type of installation.

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