Replies

1. 
   MojoMan | Dec 21, 2004 08:30pm | #1

   "Ask This Old House" just did a piece on a pump that mounts under a sink and pushes water from the hot supply line back through the cold supply line so the homeowner wouldn't have to run all that water down the drain waiting for the water to get hot. They had about 100' of 3/4" pipe between the water heater and that sink, and it took a long time for the water to get hot.

   It seemed like and interesting way to treat the symptoms without curing the disease.

   Al Mollitor, Sharon MA

2. 
   wookie | Dec 21, 2004 08:40pm | #2

   I've installed one for a longtime customer, I was a little hesitant, they are pretty picky. I explained that this system was new but from an established company. they have a large home two storey, cathedral ceilings, basicly this was the only option cost wise. They love it. I put a mix valve in kitchen and master bath. Unit has been in service 6 months, just replaced master mix valve check valve failed. Grundfos sent a new one next day no hassle. I like the timer on the pump easy to use and multiple settings. Laing and metlund make a system but have heard negative comments. The Grundfos system is new but I'm familiar with thier pumps. So far so good.

1. 
   EdJW | Dec 21, 2004 09:46pm | #4

   Wookie, The one thing I liked about the Grundfos is the fact that you can put the valve in multiple locations and that I don't need an electrical outlet under each sink.  The other thing I was looking at was a very small hot water heater under the sink connected to the hot water line.  -Ed

1. 
   JetBoy2 | Dec 21, 2004 10:25pm | #5

   I did a 2-1/2 gal tank in the vanity for the most remote bathroom sink. This was connected on a "T" to the cold water line since connecting it to the hot water line would end up leaving a bunch of HW in the piping. As is, I never anticipate this sink needing more than a gallon of water at a time. If more water is needed, a bathtub is only a few feet away. I did it primarily because my wife would turn on the tap, wait 20 seconds and still not have hot water, so she'd walk away to do something else. I can't count the number of times I've walked past that bath with the tap running full-on and no one in sight. As it now stands, there is hot water instantly, and my blood pressure has returned to normal. ;-) I also have it set at 100 degrees for safety as the toddler can manipulate his potty seat to get to the taps.

2. 
   wookie | Dec 22, 2004 05:54am | #9

   Yes, the Grundfos system is fairly easy to install as a retrofit. Small point of use are more trouble, electricity,t&p drain and pan. The small heaters in my limited experience leave a lot to desired as far as quality. By the way when setting timer on Grundfos have it start @ 20MIN before you will need it hot its a slow process.

3. 
   csnow | Dec 21, 2004 08:46pm | #3

   Grundfos circulators are top notch goods.  The UP series circ with the timer and thermostat is a wonderful device.

   One problem with using the cold line as the return is that you will get warm water from the cold tap until it clears the line (sort of trading for the opposite problem!).

   If you like your cold water cold, this could be an issue, perhaps more of an issue at a kitchen sink.

   I prefer a dedicated return line, but can appreciate why someone would want this solution for a retrofit situation.

   There is also the 'on-demand' recirc design with a point of use switch.  At least this way, your cold line would be cold unless you decide to fire the pump.  Metlund seems to be the big player, though you could potentially wire up any properly sized circulator to do the same thing.

   http://www.gothotwater.com/

4. 
   DavidThomas | Dec 21, 2004 11:37pm | #6

   For hand-washing a small, remote HWH tank is a better idea like the poster above mentioned.

   For kitchen use, I'd put in a 1/2 gallon HW dispenser first.  Either I want a lot of medium hot water (doing dishes) or I want a little bit of really hot water (making tea, cocoa, filling a pot to steam veggies). 

   For a lot of HW, I let the faucet run a bit.  For a little bit of 180F water, the dispenser ($150 ish) is great and easy to retrofit.

   David Thomas   Overlooking Cook Inlet in Kenai, Alaska
1. 
   EdJW | Dec 22, 2004 02:52am | #7

   Dave, did you connect this to the hot or cold water?  My thought was to use a 2 1/2 gal. under the sink in series with my main hot water tank in the basement.  The main reason I need the hot water is for an Aprilaire 360 humidifier I installed on my 1st floor.  I have a 1/4 inch line tied into my hot water line which is about 50 feet of 3/4 pipe.  The water cools off to quickly for the amount of water the humidifier uses.  -Ed

1. 
   DanH | Dec 22, 2004 05:30am | #8

   When I installed my Aprilaire, I ran 1/4" copper back to near the heater, threading the copper through a piece of clear poly hose to insulate it some. Of course, I only had to run about 15 feet, but I picked that over a 5-foot run from a pipe farther from the WH.

2. 
   DavidThomas | Dec 22, 2004 06:12am | #10

   Since I only use mine for food and drink, I connected it to cold water (spends less time in the pipes). It is a NSF-approved, 1/2 gallon, insulated SS tank. I also run it through a replacible carbon filter.For a 2.5 gallon tank in a low-flow situation, I'd connect to cold. If it sees bigger uses (dish washing, wash the dog, etc), I'd connect it to hot for the eventual recharge.David Thomas   Overlooking Cook Inlet in Kenai, Alaska

1. 
   BillHartmann | Dec 22, 2004 10:28am | #11

   Mine HW dispenser instructions said to connect to the cold water supply.But the orginal one was plumbed to the hot water side. But after I replaced the WH I started getting a bad taste so I replumbed it to the cold side.Now we have good water, but I got a new refigerator with filter and I really like the taste of that water. So when that filter needs replacing I am going to remove it and instead install an under cabinet version that will supply both the refigerator and the HW dispenser.