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Author:
jeffasweet (CA)
Hi All,
I've been researching my questions on here, plumbingsupply.com and the internet as a whole. I can't find the exact answers so I thought I'd post here.
Background:
1100 sq ft 1918 house that we just purchased and are having repiped.
2 Bedrooms and 1 bathroom. Furthest bathroom fixture is probably 15-20 feet from gas water heater.
My plan is to have a 1/2" return line back to the water heater. I will have my contractor who is doing the repipe do the actual install, I'm just doing the research and specifying parts.
I'm trying to duplicate a system such as this one shown on plumbingsupply.com
Pump I'm going to get is the Grundfos UP 15-29SF that has the flanges. I also picked up a check valve. What I haven't gotten is the flange adapters and valves. Since I'm going with a 1/2" copper return line, what do I go with for the incoming valve? I was thinking of going with the webstone valve kits that have valve and flange integrated:
[www.webstonevalves.com]. If I go with one of these with a drain, then I could use that drain to drain the water heater if I put it between the heater and the pump? The return into the water heater is 3/4" I believe.
Questions I have here, are, is it ok to have the return go back into the drain or is the cold better? I've seen it done both ways.
Do I put the check valve before or after the pump? From what I read, it doesn't matter. One thread I read, something about putting it above the level of the tank. I could put it up by the ceiling joists in the basement, before it turns to come down to the drain.
I see in the image an air release indicated, and I also see discussion about drilling a hole in the check valve. I'm sure they're unrelated. Is an air release in this type of system necessary? If so, what is the recommended model and where in the line should I put it?
For system control, I want to put a motion detector in the bathroom that turns the pump on when someone enters the bathroom. I'm also going to have an aquastat on the outside of the pipe to turn off the pump when the water reaches temp. I'm not sure if I'll put it on the outside of the far end, or back by the heater. I also plan to insulate all of the pipes.
For the motion detector, I'm debating on going with x10, zigbee or insteon. I also am thinking about putting a current sensor on the dishwasher so when it's on, the pump will run. I don't really want to go with a timer, because really, I don't need it running that often. I'm putting in the system just to save the extra water that runs down the drain when we start the shower.
Thanks for all of the help.
Jeff
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Author:
m & m (MD)
..."Furthest bathroom fixture is probably 15-20 feet from gas water heater..."
IMO, you're spending buku dollars to save a few nickles but then I don't reside in CA, so maybe you've calculated the savings.
I have always brought the return back to the cold inlet and the pump just prior with no problems, and set my check valve(s) on the inlet side of the pump.
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Author:
jeffasweet (CA)
I figured out one thing, if I put the check valve between the pump and the water heater drain, then I won't be able to use the integrated valve to drain the water heater.
I know I'm spending an inordinate amount of money to save a few gallons, but I'd feel better saving those gallons plus the convenience of having the instant hot water.
Now to just figure out the pipe routing as well.
Thanks for the help.
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Author:
packy (MA)
if you must have a recirculating line for that short distance, do a gravity type system.
unscrew the drain valve on the heater, screw in a nipple and tee. put the drain valve back into the tee and use the othe side for a return.
couple of nipples, a ball valve or two, a check valve with a 3/16 hole drilled in the gate and some 3/8 soft copper tubing for the return line.
insulate all the piping very well and you will hardly notice and extra fuel usage.
leave off the last 18 inches at the bottom of the return so that water will cool more and create the gravity flow.
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Author:
bernabeu (SC)
hear ye, hear ye
the lord Packy has spoken
==============================================
"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638
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Author:
jeffasweet (CA)
Ok, I'm thinking of going with Packy's advice. Trying to find some diagrams that show the concept of the gravity recirc system.
Packy said 'couple of ball valves', why a couple? Wouldn't I just need one to shut down the loop or would I want one at the start and end?
For the check valve, if I'm using a 3/8" return line, would I go with a 3/8" check valve, or would a 3/4" check valve be ok to size up to?
I'm guessing I'd use a 3/4" T with a 3/8" in the middle for the return, using a check a few feet up?
If anyone has some links/images they could share of a diagram, it would be VERY helpful to share with my plumber who I believe doesn't have much experience with these types of systems.
Thanks Jeff
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Author:
packy (MA)
before we go further, is your house on a cement slab or a basement below with bath/kitchen above ??
gravity will not work if all on same level..
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Author:
jeffasweet (CA)
Single story house, unfinished basement with water heater located there.
I went to HD and picked up a couple of rolls if 3/8" tubing, a 1/2" tee, and 1/2" to 3/8" reducer. I also picked up a pair of ball valves.
Of course they didn't have all the necessary 3/8" fittings, or a 3/8" check. No insulation either if that size.
So one thing I'm unclear on is the size back up to get into the water heater tee.
Thanks for the help.
Jeff
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Author:
jeffasweet (CA)
I think I discovered that 3/8" tubing actually takes 1/4 tees and fittings. What about for the ball valves?
Also, with a system like this, will it cause the water heater to run all the time as the cooled water is returned back into the heater?
That was one thing I was trying to avoid by having the pump tied to a motion sensor.
I'm pretty sure the answer is going to be "insulate your pipes well and heat loss will be minimal" but I thought I'd ask.
Thanks again,
Jeff
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Author:
packy (MA)
when the pump kicks on, it move a heck of alot more water (gallons per minute) than a gravity system does running all the time. see next post for piping details.
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Author:
packy (MA)
remove the drain valve from the botton of the water heater.
install a 3/4 by 3 brass nipple.
put a 3/4 x 3/4 x 1/2 inch tee onto the nipple with the 1/2 inch looking straight up.
screw the drain valve back into the end of the tee.
screw a 1/2 x 3 brass nipple into the branch of the tee.
screw a 1/2 inch ball valve onto that nipple.
screw a 1/2 x close brass nipple into the ball valve.
(take a 1/2 IPS brass check valve and drill a 3/16 hole in the gate)
screw that 1/2 inch check valve onto the close nipple.
(the gate on the check swings upwards to open so it sets down by gravity when closed)
screw a 1/2 inch male by 3/8 compression adapter into the gate valve.
(this end is now done)
up at the bathroom i can't tell you where to locate a 1/2 inch copper tee as it depends on your existing piping arangement..somewhere between the last two fixtures is the most common.
so, cut in a tee at the bathroom as close as possible.
sweat in the tee, a short piece of copper tubing, a 1/2 sweat ball valve, another short piece of copper and a 1/2 inch copper by 3/8 compression adapter.
that's it.. roll out the 3/8 copper tube, insulate it and slide it into the compression adapters at each end..
everything is 1/2 inch except these two adapters and the drain valve end.
lastly, crack open a can/bottle of your favorite beverage..
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Author:
jeffasweet (CA)
Awesome parts list, perfect!
One question, I've been unable to find hangers for 3/8" copper, do they make them, or should I just use 1/2" and pinch them down some?
Where do I send the beer?
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Author:
packy (MA)
you are going to need 1 1/4 inch galvanized clips or 1 1/4 inch pvc j-hooks. remember the 3/8 is going to have insulation covering it.
also you want 3/8 ID armaflex insulation. solid, not split.
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Author:
jeffasweet (CA)
Packy, great info.
I read somewhere about using fiberglass insulation for the supply lines than the normal foam type with the splits. Does the fiberglass insulate much better?
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Author:
jeffasweet (CA)
I'm having a hard time finding the 3/8" Armacell. I can order through Sears or NewEgg for delivery through Plumbing Planet. I can't find it on plumbingsupply.com.
Anyone have advice. Would someone local have that size? I'm in San Jose, 95126.
Thanks Jeff
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Author:
steve (CA)
Try an HVAC supplier -
Edited 1 times.
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Author:
packy (MA)
fiberglass does insulate better than armacell. but armacell is very flexible and just slides on easily.
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Author:
jeffasweet (CA)
That Armacell is REALLY hard to find. I tried every HVAC and plumbing supplier in San Jose. Ended up ordering online through a large retailer that is just a reseller for an obscure plumbing supply company.
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Author:
jeffasweet (CA)
Packy,
I have one more question. When I'm running the 3/8" line across the joists, if I need to drop down under one of the cross-members and buck up a bit to continue on, will that kill the loop, or should I drill through it so that it is a continuous downward slope? When I gets to the end, it will drop rapidly to the water heater.
Thanks Jeff
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