Replies

1. 
   fortdh | Dec 06, 2003 04:24pm | #1

   Woody, there have been some discussions on this fairly recently. I trust you are talking a one story house. If you can put in a return line from distant fixture back to the water heater, you can install a pump, insulate the lines, and use a timer to match hot water need habits.

   If you have enough height difference from high fixture to water heater, you can use a gravity flow return with a check valve in line.

   If your present plumbing hops around in series from one room to another, you may find a direct line to the distant fixture would greatly reduce the wait time and temp loss. (you could test this with a garden hose)

   My son's house on slab had the same problem...warm only kitchen water regardless of how long he let it run. Slab and distance robbed the heat.

   We had to run a line from heater in attic direct to kitchen, where faced with tearing out ceiling, wall and cabinents.Instead, we ran the line from one corner at ceiling where we could enter the kitchen, across top of wall to the stud bay of sink, back into the wall and down to sink base cab. To cover this installation, we installed crown molding to my daughyer-in-law's delight. Now the kitchen has fast hot water, and the only 10' of radiant heated crown molding I know of!

   Hope this helps. Paul

   Energy Consultant and author of Practical Energy Cost Reduction for the Home
1. 
   edwardh1 | Dec 06, 2003 05:13pm | #2

   OH Nooooooooo.

   Us dummies have enough problems cutting crown moulding angles now - you are throwing in another variable........ be sure to allow an 1/8 inch offset each 1/4 inch of hidden pipe diameter ---- a whole new world now........

1. 
   fortdh | Dec 06, 2003 07:22pm | #5

   Wain, it really wasn't a problem. Just had to be sure to not put a finishing nail into the pipe. We did it three years ago, and everything still tight...all joints and corners. Actually, the cpvc pipe does not contact the back of the crown molding. Tks, PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

1. 
   edwardh1 | Dec 06, 2003 07:28pm | #6

   Just kidding--thanks

1. 
   fortdh | Dec 06, 2003 07:47pm | #7

   Wain, I couldn't see your smile...but we allowed .001 mm for each deg of delta-t between room temp and water temp divided by the specific gravity of cpvc. We then painted it...

   What did you decide about your son's heat system in NY?

   PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   LarryG | Dec 06, 2003 05:46pm | #3

   Paul I already have a system in place its  cpvc 3/4 inch pipe loop a pump at the at the water heater on the hot water side pushing the hot water around and a check valve at the return side into the cold water side of the water heater, also a check valve on the cold water feed to the water heater. There is a thermo switch to sense water temp at the hot water return check valve which is supposed to cycle the pump but it doesen't the pump runs constantly. A check with a VOM shows that the switch only opens with the flame of a cigarette lighter and it has to be held there for 20 seconds which makes me think its faulty (a new one has been ordered). This is the system I have in place now. This system works well for a while but with the pump running all the time  a problem arises, if you get up in the middle of the night and want a cold drink of water you have to wait a minute for the water to turn cold. I don't understand how this can back feed I have changed both check valves . I think if the pump was cycling properly this may not happen. What I was looking for  is possibly a different type of system or some comments on the system that I have. This was a 40 foot house that I remodeled into a 100 foot house and the hot water is the only thing that has given me any hassel also the water in the four showers is luke warm and the sinks are hot but I think this maybe has something to to with the way the showers are set up the no scold thing and maybe they can be adjusted. All comments are welcomed. Thanks

1. 
   fortdh | Dec 06, 2003 07:16pm | #4

   Woody, hopefully some of the master plumbers will jump in.

   Re: valve only activates with cig lighter... Faulty valve.

   RE: wait for cold in middle of night. It may not be circulating past check valves, but transfering heat from hot side through mixing faucet to the cold. Rather than circulate all the time, have you tried a timer?

   Do you have an expansion tank in the loop? You have check valved the hot loop closed, if I understand your description, and the hot water expansion has no where to go. What is energy source for HW heater?

   Re: hot sink/warm shower, I would suspect the anti-scald settings, unless pipe goes into a slab between sink and shower.

   Without hands on, those are my guesses. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   sphaugh | Dec 06, 2003 07:55pm | #8

   Have you considered a demand water heater, either gas or electric?  One of those small "point of use" heaters might solve this problem more easily than running 100' of pipe.

   
   

   ---

   Edited 12/6/2003 12:01:33 PM ET by SPHAUGH

1. 
   daddoo | Dec 06, 2003 09:35pm | #9

   On every job we do where we add or replace a hot water feed, we alway do the following. From the hot water heater, we run either a 3/4" or 1" copper line (depending on distance, pressure or number of appliances) to the farthest point of usage. We try to install the pipe to get as close to every appliance as possible. When we reach the last appliance, we drop down to 1/2" pipe. and run back to the hot water heater, where it returns into a tee installed at the hose bib/drain. We install a small circulating pump in the 1/2" line next to the how water heater with a thermostat checking the returning water. When the returning water temp is too cool, it will circulate the water. Warm water will shut down the pump, which usually happens during continued usage. We also try to pitch the lines slightly to allow for a gravity effect, and a check valve is also used. Clients love it when the shower in the master bath, far from the basement HWH, has steaming water in two or three seconds.When all else fails, use duct tape!

1. 
   fortdh | Dec 07, 2003 04:52am | #10

   That is a very nice set up. I would probably add a timer to leave the system off during most of the night, and if away during the day. Have you tried the system with gravity fall only, ie.,no pump. Also note you tie in at the bib, which is better than at the cold inlet on top of the tank due to the heat in the dip tube at the top. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

1. 
   daddoo | Dec 07, 2003 10:10pm | #11

   We have added timers on some projects, but it is not a default. Families with kids have more of a 24 hour demand than just a couple living alone, so shutting it down for the night can sometimes backfire.

   He have done gravity only systems; I have one in my own home. They work best in more vertically designed structures, where there are no long horizontal runs. If fact, I used two completely separate loops to optimize efficiency. I also didn't want the addition of the electrical cost of a constantly running pump. I am still far below the worth of most of my well-to-do clients.

   I have also run tests on my own house to determine if this installation saves or costs more money to run. I have found that if the lines are well insulated, you could probably use a smaller water heater, since the lines themselves act as part of your storage capacity. Using a hot water heater that is too big causes it to cycle less and fire longer. I still need more input to make a determination.When all else fails, use duct tape!

1. 
   donpapenburg | Dec 08, 2003 04:22am | #14

   I did mine without a pump or check valve.  I made sure that the return line was lower than the hot and at a slight slope returning to the water heater . At the water heater it goes straight down to the drain bib. I have a ball valve there to regulate flow.  works fairly well

2. 
   LarryG | Dec 08, 2003 05:54am | #15

   Thank you all for your imput it made me stop and think a little  , the shower water temp was as I thought an adjustment at each one of the shower controls and this morning I stopped at a local Taylor wood fired stove dealer and the owner was there and after a short chat I purchased from him a used water thermostat and a well fitting and took it home and rearranged the pluming layout  and now the circulator pump comes on very infrequently and only runs for about  a minute and all works fine. I don't think that this will raise my heating costs much. I feel the instant hot water is worth it. You have to remember I was born and raised in Brooklyn and we didn't have hot water when I was a kid so you can see why this makes me happy. Talking about happy  I want to wish all of you a happy holiday, and I will be going back to NY for the holidays

3. 
   markls8 | Dec 08, 2003 07:23am | #16

   A check valve is needed if you want to prevent the colder water in the line returning to the water heater from being drawn backwards up to the fixture at the same time as the hot water is when you turn on the fixture.

   Regards - Brian 

4. 
   donpapenburg | Dec 09, 2003 05:53am | #22

    I have a 3/4 feeder and a 1/2 return that is lower than the feeder and drops straight down at the WH and into the drain bib.  I also have a ball valve on the return to regulate flow.  I have not had a problem with the cold coming back up the return yet . the water gets hot enough that it would be nice if it did bring some cold back.  It is a termal syphon loop with the return running below the hot line and falling as it goes back to the heater.  At the heater it enters at the bottom of the tank.

5. 
   markls8 | Dec 09, 2003 07:01am | #23

    So,  Don - do I have this right? The difference in temperature between the two loops is not great enough to noticeably affect the water temperature at the fixture?

   I also like the bib connection idea. Mine is already installed at the top of the tank (boo hoo). Maybe someday I'll change that, but until then it's been working fine - two PEX loops balanced with ball valves serve two bathrooms, a powder room and a laundry sink. All lines insulated with pipe wrap in the walls.

   Regards - Brian.

6. 
   donpapenburg | Dec 10, 2003 05:14am | #25

   Lets see , the water is at 120 outgoing  sometimes warmer. 3/4 pipe ,insulated copper.  The return is 1/2 copper uninsulated, I wanted it to cool  more as it returned  to help the thermal syphon effect.At the water heater I can hold onto the return pipe but I let go of the outgoing pipe rapidly. My return starts about ten feet from the end of my runs. Only need about a gallon of water to flow hot hot water.  With the ball valve closed I have to run more than 4 gal to get hot water. If that answers your question.

7. 
   markls8 | Dec 10, 2003 06:44am | #26

   Yup, it does.

   One thing though. I insulated both lines. The idea there is that while leaving one line uninsulated does, in fact increase the temp difference and thus the flow due to increased thermosiphon pressure, insulating both lines reduces the flow, and results in a corresponding reduced need for higher flow because the water is still hot.  So you end up with the same net result but with less heat loss to the surroundings - not significant in wintertime, but may or may not be in summertime.

   Regards - Brian,

   Edited 12/9/2003 10:47:06 PM ET by MARKLS8

2. 
   JohnSprung | Dec 09, 2003 03:31am | #20

   > Also note you tie in at the bib, which is better than at the cold inlet on top of the tank ....

   My WH has a 3/4 NPT plugged hole in the side about 10" down from the top.  A plumber told me this was for the return of a circulating loop.  Is that correct? 

   The purpose of the bib is to clean crud out of the bottom of the tank.  Does this flow tend to stir the stuff up?

   -- J.S.

1. 
   fortdh | Dec 09, 2003 04:36am | #21

   John, all the water heaters that I have seen with a plug 10" down from the top, also have one about 10" up from the bottom...unless they did not install a T&P valve in the side. Do you have a pressure relief valve on your tank?

   Using a tank with high and low side ports, the upper one is for hot water to the heating system, and the lower one for return. Side ports help prevent air bubbles from entering the heat system, by letting the bubbles float to the top of the tank and head for a faucet/sink etc fixture.

   If you use a tank that does not have side ports, in a heating system, then you should branch off horizontally from a line going up to an out -flow fixture. You don't want air in the heat exchanger or pump impeller.

   Re clean out bib. When opening the base bib, the inflowing cold water from the dip tube will stir up some sediment, which is good as it helps flush it out of the tank. Returning water to the base from a circulation heat loop wouldn't be as violent as normal incoming water. Actually, I would rather have stirred up crud than a crust over the tank bottom if using gas fired.

   PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home

2. 
   JohnSprung | Dec 09, 2003 11:18pm | #24

   > Do you have a pressure relief valve on your tank?

   Yes, all the heaters I've seen around here have the T&P valve in the third hole on top.  Not sure if it's code or custom to always do it that way.

   As for the bib, I've replaced it with a full diameter ball valve.  That way I can drain the tank completely and stick a plastic coated coathanger wire in there to stir up the crud and get more of it out.  Someone here recommended using a boiler cock for this instead.

   -- J.S.

    

3. 
   baseboardking | Dec 08, 2003 03:32am | #12

   Hey Woody: I put a HW circulator loop in my house. I used an additional 350 gallons of oil per year for the joy of "instant" hot water. I disconnected it- I wait a few seconds and save alot of $$$

   Baseboard been VERRRY good to me
1. 
   migraine | Dec 08, 2003 04:09am | #13

   Is this the norm for a return system???   We are going to put one in our home and now you have me wondering.  Can anyone else give their experiences on it.   One plumber who worked on a job where I was working said that the cost of saving water was about the same as the cost to keep water constantly hot.  I never totally believed him, but what you stated blew my mind... 

1. 
   baseboardking | Dec 08, 2003 03:17pm | #17

   Hey, Migraine: Well. in my case water is "free":

                           Drill well @240',casing                                 $3500.00

                           Install pump, pressure tank,controls           $2800.00

                           Electricity to operate pump/ monthx12        $960.00

                           Cost for "free" water                                   $7260.00

   Again, I prefer to wait for hot water. As a residual benefit, it is argued that a little pipe flushing prior to water use is helpful in purging impurities, bacteria from the plumbing.

   Also, please understand that my domestic h/w is supplied by a Weil/McLain boiler with a Plus 60 super insulated tank. This system is the quickest recovery(virtually unlimited hot water) but may have a higher cost to produce.

   Regardless of the source, there is a significant energy cost to keeping hot water constantly circulating through the house. Remember that if you position check valves, the water is not circulating, negating the instant- hot feature.

   I'm also probably a little more frugal than most which drove my decision to disconnect. Goog luck with your decision.

   Baseboard been VERRRY good to me

1. 
   migraine | Dec 08, 2003 07:11pm | #18

   My last home was on well.  It's depth was 884', just to get 8gpm.  Going rate now is about $17.00 per foot with casing for a 7" hole.

1. 
   baseboardking | Dec 08, 2003 08:29pm | #19

   That's a verrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrry deep well!

   Baseboard been VERRRY good to me