House built in 1910. Entire plumbing system replaced 3 years ago. Full 3 story house with full basement. Shower on 2nd and 3rd floor. One oil-fired hot water heater, in basement, 3 years old. Presumably sized correctly for 2 adults and 3 kids – I’ll check on the size tonight if that is deemed important.
Off the hot water tank run 3 separate 3/4 inch lines – one to 3rd floor bathroom, one to 2nd floor bathroom, and one for main floor and basement (combined). On the 2nd and 3rd floor, the 3/4 lines run to the shower and sinks are t’d off the run to the shower.
First floor has 1/2″ return to the water heater. This is certainly the shortest loop and is virtually all horizontal. 3rd floor has 1/2″ return to the 2nd floor shower where it t’s in with return from 2nd floor shower and runs down to water heater using a 3/4 line. At the heater, the 1/2 (first floor) and 3/4 (3rd and 2nd floor combined) return lines join together and continue in a 3/4 line to a Grundfos pump, then through a valve (spring type) and into the hot water heater drain connection at the bottom of the heater. Pump runs 7/24.
Lots of bends and turns – runs are certainly not straight. Little is insulated – virtually none. Bygones.
I am planning to add a timer, a thermostat, and a shut off valve to the return line to control the pump – clearly I don’t need to run the pump around the clock, nor do I need to run it when the temperature of the water returning to the hot water heater is hot.
And so, what is the problem? We run out of hot water in the showers – seemingly fast. By the end of the shower, the hot water is on full and cold is virtually off (showers have two control valves, not a single lever). And I’m running the hot water thermostat at about 130. Going even hotter doesn’t really help.
If I turn off the pump and shut off the return line valves, after an expected long wait, I get quite hot water at the shower head which lasts longer.
So the return system seems to be hurting, not helping.
Thots? Should the 3rd floor not tie into the 2nd floor return? Is the return temp thermostat and the shut off valve likely to make a huge difference to the water condition (I know it will save electricity and hot water energy). Do I just need a bigger hot water heater? Something else?
Help. Sorry for the long post.
Cheers.
JGV
Replies
The circulating system is hurting two ways:
1) It's causing lost heat.
2) It's causing the hot and cold water in the WH to mix excessively, vs allowing the hot to stratify near the top.
Ddin't really understand all your description, but...
If you're running out of hot water, the problem is likely something other than the recirc loop. Like maybe something's wrong with the water heater.
The loops are intended to give you hot water at the fixtures more quickly. They're not designed to KEEP hot water flowing.
A: Why do women do ANYTHING?
I doubt that the system is loosing that much heat through the return pips that the heater can't keep up.
It is possible that the flow rate is too high and mixing the water in the tank as Dan suggest. But that depends on how big the pump is.
But my best guess is that the problem is that the check valve is bad and allow the cold water on the bottom of the tank to circulate backwards through the return lines.
Hi all.
May well be a mixing problem, that is certainly my wife's opinion. I'm not sure I understand where. In the tank or from the configuration of the lines?
Valve is new - just went in this weekend. And it is in the correct way. :-)
The pump is the one that was recommended for this application but that doesn't necessarily mean much. At the moment, since last night, the pump is disconnected and return is just through convection. Can't say I notice any significant difference though. But today was the first day and I didn't get everyone else's opinion.
Is the trick to adjust until I have mildly hot water on the third floor immediately with the very least hot water being returned? Seems the answer to that is yes. If that is the case, the slowest pump possible which is turned off as often as possible is what I'm trying to achieve.
What about the 3rd and 2nd floor return lines joining together. Does anyone see that as a significant issue?
CHeers
JGV
I think that spring loaded valve that you mentioned is the check valve.When you run into the problem of lack of hot water, with the shower still running feel the hot water supply pipe and the return line.They should normally be the same temp within a few degrees.But if cold water is flowing backwards throuthe return line it will be much cooler.
now to thicken the plot...
is the pump on the end of the line or at the beginning???
or ...
is the pump drawing directly from the WH and sending the HW to the fixtures or pulling the HW from the fixures and pumping the it back into the tank...
please be certain of this..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Pump is about one foot from the drain connection at the bottom of the hot water tank. So, the pump is not "pushing" the hot water around the loop, it is pulling the hot water around the loops, then through the check valve, then into the bottom of the hot water tank where the hot water tank drain is.
The pump is for certain pimping in the correct direction. THe check valve is in in the right direction.
Cheers.
JGV
With the pump where it is, if you have a single-handle valve somewhere that allows a lot of water to "bypass", that could be your problem.Occasionally you'll see a situation where a shower valve or some such will be designed such that fairly large volumes of water can "bypass" between hot and cold when the shower is in use. This isn't a problem if the hot and cold are at essentially the same pressure, but can be a problem when there's a pressure difference.However, one would generally expect this problem to present as the water almost immediately going cold "downstream" from the problem valve, regardless of when in the "cycle" of water heating the valve is opened.
good...
I seriously doupt your circ system is costing you significante amounts of HW...
time to dig into yur WH and how long do the showers last???
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
plan "B" or .... pick one...
or additional thinks...
can you measure the supply line in real time temp of the HW and the real time temp at the return??? (wrap a thermometer on the line for a few minets)
you may be over / under pumped... is one pump for / on all three lines in a manifold configuration... or 3 seperate pumps...
or...
you may be better off with 3 seperate thermostaticly / timer contolled small pumps...
note too slow of a pumping action / flow and the water cools a lot... Cold water returned to WH for heating and mixing down yur HW...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
"...then into the bottom of the hot water tank where the hot water tank drain is."
I'm no plumber, but that doesn't sound right. Is that kosher, using the drain valve?
Q: Why do little girls whine?
A: Because they're practicing to be women.
Yes, that is common practice.A T is installed there for both the drain and the return.With a power circulation system it could be returned to the cold water.But for gravity feed then you want the extra height, at least for a 1 story house.
"But my best guess is that the problem is that the check valve is bad and allow the cold water on the bottom of the tank to circulate backwards through the return lines."
My sentiments exactly. That happened on one of my recent projects. The check valve was sticking in the open position. Replaced it and all was fine again.
Morning all.
Some additional info......
Hot water tank is 32 gal and I have been assured with the oil burner the recovery rate is quite adequate for our family needs. So says the fellow who sells me oil.
Grunfos pump is model UP 15-32F. However, at the moment is it electrically disconnected but still inline in the system.
Gate valve is new. Been in the system for less than a week. I really don't think this is the issue, but I may be wrong.
Hot water tank temperature is set for about 130.
With the pump disconnected, and the 1st floor return line closed, there seems to be some recirculation by convection. The return line is slightly warm to the touch - slightly. The hot water line out of the tank you can't hold.
With respect to the lines, the pump, and natural convection, from the hot water tank, the 1st floor line goes up about a foot and then runs horizontal through the basement ceiling space. The hot water return line is parallel to the supply line - it doesn't turn down. However, the 2nd and 3rd floor supply lines must make a 1 foot drop off the water heater to go under a staircase before they go up to the 2nd and 3rd floor. I'll agree undesireable but there was no other choice. Other than this drop right at the water heater, the remainder of the lines goes up or horizontal. The return lines come down or horizontal. Why am I adding all this? Not sure, but last night as I stood there trying to have some sort of conversation with the water heater I occured to me that this may be important.
Seems to me that the system has enough height that from a convection standpoint, the heat still is drawn up even though it is faced with the 1 foot drop initially.
Tonight, I'll pick up a couple thermometers and tape one to the supply and one to the return. Maybe I'll get three and put one on each return.
Oh, and wrt the length of shower, seems to be between 5 and 10 minutes.
Cheers.
JGV
If you posted the right model number, you have the wrong pump. a UPxx-xxF is a cast iron pump, intended for a closed system. You want a UPxx-xxSx or UPxx-xxBx stainless or bronze for an open system.Your current pump is probably corroded.
I couldn't find info on a UP15-32F, but the UP15-42F seems to be corrosion resistent.
The "open vs closed" thing is confusing to me. I think of those descriptions in terms of hydronic heat - "open" meaning that potable water circulates through the heating tubes and "closed" meaning that potable water and heating water are kept seperate.
But what does "open vs closed" mean in JGV's application?
Description
The Grundfos UP15-42F 1/25 HP Recirculator Pump with cast iron pump housing.SPECIFICATIONS• Flow range: 0 - 17 U.S. GPM• Head range: 0 - 15 FEET• Motors: 2 Pole, Single Phase, 115 Volt• Maximum fluid temperature: 230°F (110°C)• Minimum fluid temperature: 36°F (2°C)• Maximum working pressure: 145 PSI • Connection: Flange - (2) 1/2" Diameter Bolt HolesFEATURES and BENEFITS• Bronze and stainless steel construction.• Wet rotor design.• Composite impeller.• Eliminates and prevents corrosive effects of fresh water.• Maintenance-free, low energy consumption, easy to install, quiet running.• Improved performance and efficiency.• Pre-program usage times to save power.• No additional wiring required.• Adds to savings by operating pump by sensing the water temperature with optional timer and aquastat.
Details and Features
Manufacturer: Grundfos Pumps
Model: UP15-42F
Oversize: No "Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
Hi all. Using termometers taped on the pipes, the temperature leaving the hot water tank seems to be about 100 degrees F. With the pump electrically disconnected, the return pipe temperature hovers around the 82 degree range. The temperature of the return line does drop a few degrees after a shower.
Showers seem to last from 6 to 10 minutes.
At this point, I can see myself reworking various bits of this as time, money, and individual renovations near the pipes allow. Things I'm going to focus on, in no priority order:
* run seperate return line from 3rd floor to basement with 1/4 inch copper
* replace 2nd floor and 1st floor return lines with 1/4 copper
* insulate supply and return lines
* put individual gate valves on each return line
* put timer on hot water return pump to restrict running to early morning and after dinner
Any other thoughts?
Thanks all. Cheers.
JGV
Do you still have the problem with the pump off but the return line valves open?
"Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
I would say yes. By turning off the 1st floor line and the pump, the situation has improved. However, we still seem to be running out of hot water too soon. I do believe there is some sort of mixing problem somewhere.
JGV,
I like it.
I would use ball valves instead of gate valves. I would also put individual ball valves on each feed line and the common return to heater line. Then I would put individual back flow valves on each return line, and replace the pump with a timer valve.
Add a drain valve between the individual return ball valves and the common return shut off ball valve, and you've got a winner.
SamT
100* out...
you have a low temp to start with.. mix cold with that during a hower and it drops further...
look a little harder at the WH...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Could just be poor contact between thermo and pipe. Put some sort of pipe insulation around the area where the thermo is attached, leaving just enough opening to read the thermo.
yup...
from what I read so far - my hunch says he's diluting hot water (if ya can call 100* hot) with cold and the heater isn't making the grade and the the call rise can't be met... exchanger sooted???
he says he's set for hot at the thermostat but I'll bet the thermostat is the first thing to change to to start getting things back on keel...
and this is a closed system...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Yes, I still think that it is back feed and that the check valve is not working.
so lets find out who made and where it came from...
new outta the box junk is getting more common all the time...
but a closed system shouldn't be costing him all that HW....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Imerc,
Here's a schematic of JGV's DHW system. The skinny line is 1/2", the rest are 3/4".
View Image
As far as the corrosion characteristics of the pump are concerned, it's an open system, meaning that make up water and oxygen are constantly being added.
SamT
Sam....
got it... with that much 3/4 he has a radiator then...
still output on supply side should be better than a 100* - 120/25???
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Imerc,
He's got the boiler set at 135*. A 35 gallon boiler.
He says showers last 6-10 mins. A 3 gal/ minute showerhead would run out in 10 mins with just HW flowing, say 15 mins under normal use.
150' of 3/4" pipe has 30 sqft of surface area and I dunno how many gals of water.
He was running the recirc pump 24/7. How many BTUs/day will 30 sqft of copper put out at 135*? In the winter. It would sure be toasty standing in front of that 6'x5' sheet of hot copper.
I wonder if his boiler is kaput. Needing service or repair.
SamT
that's what I said several times....
about his boiler that is...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
he may be set at 135 but his output is around a 100...
dielution rate is faster at a 100 than 135... yes...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
3/4 copper at 135 is about 25 btu/foot per hour. He is losing about 3750 btu per hour. Output of the burners is probably about 30,000/hour.
Right out of my catalogue, 15-42f is for a closed system. Closed is where there is no fresh water being introduced, as in a hydronic heating system. Open is a potable system. Bronze and stainless are in 15-42su,sf & b models. 15-42f is the wrong model for a recirc system.
No question that this pump was designed for a closed system. It's also obvious now that this is the wrong pump for this application.
I wasn't really questioning either of those points, but merely pointing out that this pump is advertised as having "Bronze and stainless steel construction" with a "Composite impeller" that "Eliminates and prevents corrosive effects of fresh water."
Now, a manufactor's claims may or may not be worth much. But it doesn't sound like this pump should have failed within a couple of months after being expesed to fresh water.
Also, since he's having the problem with the pump turned off, it doesn't seem like the problem is the pump or the heat loss from the uninsulated pipes.
"Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
Someone a few posts back said this is a 35 gallon heater. Is this true? 35 gallons is pretty tiny. It's not so bad in a gas unit if there are enough BTUs for good recovery, but it can still be drained pretty rapidly. Figure that you really only have about half of that capacity before mixing starts cooling the outgoing water substantially.
I agree. That seems like a very small unit for a family of five.
The puzzling thing is that the system seems to perform adequately when the return lines are closed.
"Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
32 and the recir system is sitting idle..
back to the WH....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
You get mixing without the recirc system running. When you draw hot water, cold water must come in the bottom. It stratifies a little bit, but it ain't perfect.
I know this...
if you haven't the rise to handle it or the thermostat is out in left field or has gone south learn to like cold showers or fix the heater...
think maybe a 50 plus gallon hyper efficiency will fit the bill a might better or even a 75....
now about that 3 cyclinder engine that's in that semi over there...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
It seems possible to me that you could get some significant heat loss from your loops. Your third floor loop could be 40-70 feet long. (Guessing 20 feet vertical and up to 15 feet horizontal.) Add in the the other two loops and you might have as much as 150 feet of pipe.
Do you have copper lines? Heat transfer is pretty high through copper.
It would be interesting to know if your water heater cycles, or runs continuously. If it's the latter, heat loss might be your problem.
It would also be interesting to know the temperature of your return water. Is there a temperature guage installed?
If it isn't a heat loss problem, then it does seem like a mixing problem of some kind. (That really helps, doesn't it?!?)
Maybe you could set your timer up to circulate the water prior to "shower time", but close down the system while the showers are being used. More of a patch than a fix, but it might help.
Jon
Ok, I have some measuring to do tonight. :-)
All copper lines. Water heater does not run continuously. Seems to me that it is off more than on.
I'm going to try to measure the temperature of the return water. I'll also see if I can determine exactly the size of the water tank and the model of the pump.
Timer isn't installed yet, but that is the idea - have the timer come on at 6 am and go off at say 9am then on again at 5 pm and off at 10 pm. I'm thinking the addition of a thermostat which would monitor the temperature of the return water - if it is say over 100, then the pump also turns off.
Thanks all. More tomorrow.
JGV
"Timer isn't installed yet, but that is the idea - have the timer come on at 6 am and go off at say 9am then on again at 5 pm and off at 10 pm."Acutally that is not the type of time clock that you need.What you need is a cycle timer. You will need to experiment some, but maybe run 2 minutes out of 10. The water does not cool that fast.And you can put it in series with a time of day time clock to keep off during the middle of the day and at night.
First thing you need to do is a drawdown test. Wait until the heater has shut off. Shut off the pump and close the valves on the recirc line. Use a 5 gal pail and measure how much hot water you actually get from the heater. 50 gal tank, you should probably get about 40 gal hot and the rest warm. If you don't, you need to check the dip tube. Grundfoss has a timer that fits onto the pump and can be adjusted in 15 min increments.
I agree with the dip tube thing unless its always been that way....
JGV,
View Image
FIRST: Your plumber certainly did you no favors when he neglected to insulate all the pipes on a recirc system like yours. Running your recirc pump 24/7, the extra cost of energy will pay for retrofitting insulation on the pipes in about 10 years (SWAG.) Even after you timer it down to 6/7, tthe payback for the retrofit will probably be on the order of only 15 years (another SWAG.) Think of you water system as a huge radiator filled with 130* water. In summer you have to cool the heat from this radiator, too.
SECOND: If the water in your area did not foul pipes I would have used 1/4" returns. Otherwise no larger than 1/2". I can't comment on the third floor to second floor connection, the plumber may have done a calculation I have no knowledge of. It will not balance, although that is not needed with the brute force method he used.
Personally, I don't use recirc pumps, depending on gravity as a source of free energy instead. That being said, I would have made that connection after a drop from the second floor, ie. at the first floor, or at least 1/2 way down the wall.
THIRD: I would not use a thermostatic switch on the recirc loop. All the water in the pipes will cool at the same rate, so the water at the fixtures will sometimes be cooler untill you run it for a while, then you will have to adjust the shower temp down to comfortable again. How old are your kids????
FOURTH: That "spring loaded valve" is supposed (I don't have a clue what your plumber used) to be a special backflow preventer for recirc systems. It has a weak spring. It should close whenever a valve is opened anywhere in the house to prevent water from flowing out the botom of the WH. However you have three interconnected loops which causes a really weird counterflow condition. I would consider moving that BFP to one of the two return pipes and adding another one to the other. That way you would only have the second and third floor crossfeeding each other.
FINALLY: If you're running out of hot water too soon, you have three choices; A bigger WH; Lo-flo shower heads; Shorter showers.
Use a timer valve that's only open for three hours around the times you usually shower. That will, however, agravate the crossfeed problem at other times. All the cold water in the top two loops (all three, if you leave the BFP as is) is going to mix with the hot water you want when you open a fixture valve.
Bite the bullet, add a third return pipe from the third floor down to the pump, remove the pump, insulate ALL the pipes, use a BFP on all three loops, and use a timer
SamT
Could it be that you are taking too many long showers with your wife? ;)
I've read through a lot of the posts. Have you checked to make sure the cold supply going into the hot water heater is actually piped into the "cold" supply side, and that the hot water supply coming from the hot water heater is coming out from the "hot" side? I've run into a couple of water heaters that were reversed which reduced their efficiency. The cold is typically on the right side while looking at the front of the water heater, the hot on the left.
Vegetarian: Indian word for "lousy hunter"
We're good that way. The pipes out of the tank are labled in the top of the heater as hot and cold. But I can imagine.......
By the way, anyone know where I can get the one way valves for 1/4 copper line? Should I specifically be looking for something with a flap or something whith a spring?
And, while replacing the 3/4 and 1/2 inch lines with 1/4 line, is it all wasted if I choose to not tear open *all* the drywall and end up leaving a short (lets say up to a couple ft long) section of the larger pipe?
Thanks all.
Cheers.
JGV
The guys here with practical experience may disagree, but I don't think you need to replace the entire runs of 3/4" and 1/2" pipe. Even if you replace only a 6" section, you'll reduce the flow rate down to essentially what it would be with 1/4" over the entire run. An inline flow restricter would probably look a little cleaner than a 6" section of 1/4" pipe.
I know you've said twenty times that your one-way valves are good, but I keep coming back to that as the only plausible explanation.
How about trying this. Turn off the valve at the output of the hot water heater. Then go up to your showers and turn on the hot water only. If anything comes out, it has to be back-feeding through your return pipes. If nothing comes out, you know your valve(s) are good.
"Listen, strange women lying in ponds distributing swords is no basis for a system of government."Jon
That is a great idea. Hadn't thought of it but it will sure test the back flow issue!
Any comments on where (or what brand) of oneway valves to get/use/replace with?
CHeers.
JGV
If you suspect a one-way valve is bad, just insert a regular ball valve in series. Won't hurt to have one (or even two) there anyway, so that you can service the one-way without having to drain down the entire system.
Ah, yes. I keep meaning to post results.......
Tore open a wall. There was a crossover from the 2nd floor hot water supply to the 3rd floor hot return. It was about 4 feet *before* the shower valve. That has been removed.
That helped a very little bit but didn't solve the issue. So, still the disbeliever, I shut off the hot water supply and turned on the 3rd floor hot (at this point the old 2nd floor hot return was disconnected from the 3rd floor return but the 2nd floor hot return was not complete). I fully expected *no* water to come out since as in my naivety I had reported several times that the gate valve was brand new - how could it be acting up? Well, I got lots of hot water that within a few moment went as cold as I would expect from the cold tap. Yikes! Obviously the gate vale wasn't working and it was drawing from the bottom of the heater.
I went over everything again, and again, but there was no other conclusion.
Soooooo, off comes the recirc pump (which was still electrically disconnected) and off comes the gate valve. Lo and behold, a piece of metal crud - from somewhere was holding the value open. Very humbly I said I would always listen to the sage advice of others even when I had trouble believing.
Cleaned the valve out, reassembled all. Ran the "can I get hot water backwards" test again and not a dribble.
Interesting side note - before doing this, you may recall that the temperature of the return line was often around hot or at least warm. Now, with the valve working, and the recirc pump still not connected, the return line is stone cold. Soooo all the heat that was present in the hot water return line was backflow. I presume.
So, now I'm trying to find time to complete the run of the 2nd floor hot return to the pump. I insulated everything I could get to. I elected to stay with 1/2 line rather than going down to 1/4. I also have 3 1/2 flapper type gate valves that I'll be putting on each line before they join and go to the pump. That will prevent any backflow from the other lines.
My biggest problem at the moment is trying to find a method to control the pump. I don't want running all the time. In my mind, I have two options: a controller that is temperate driven: when the return line gets to be a certain temperature, the pump shuts off. However, I would really like to have more control than that and so ultimately I believe I am looking for a timer controller. Ideally, I would like a timer that understands there are 7 days in the week and allows me a schedule for weekdays and weekends. And I want to be able to turn the pump on for a minute and then off for five or ten.
All of the timers I've seen so far are really intended for lights and don't give me the flexibility. Any timer suggestions?
I'll post this also. Thanks for your help and interest. :-)
Cheers.
JGV
Re the timer, I think you'll basically have to find some sort of computer thingie to do it. If you're a halfway-decent hacker a Basic Stamp II would probably be the ticket (though it would likely need a time reference of some sort, to keep it's clock synced).
"So, now I'm trying to find time to complete the run of the 2nd floor hot return to the pump. I insulated everything I could get to. I elected to stay with 1/2 line rather than going down to 1/4. I also have 3 1/2 flapper type gate valves that I'll be putting on each line before they join and go to the pump. That will prevent any backflow from the other lines."Actually that is a Check Valve. Of which there are several types, spring and swing gate. Sounds like you have a swing gate. It only allows flow in one directionHowever, a gate valve is completely differnet. It has a handle that moves a gate in and out to control water flow and it is birectional."My biggest problem at the moment is trying to find a method to control the pump. I don't want running all the time. In my mind, I have two options: a controller that is temperate driven: when the return line gets to be a certain temperature, the pump shuts off. However, I would really like to have more control than that and so ultimately I believe I am looking for a timer controller. Ideally, I would like a timer that understands there are 7 days in the week and allows me a schedule for weekdays and weekends. And I want to be able to turn the pump on for a minute and then off for five or ten.
All of the timers I've seen so far are really intended for lights and don't give me the flexibility. Any timer suggestions?"I have several suggestions. But I think that after doing one of these 3 anything else will be a diminishing return.1. Thermostat control to shut it down until the water cools at the far end.2. Interval timer to run or a short time period such a 1 minute out of ten.3. Time of day control - only allow the system to work during certain times.I am looking at Mosser Electronics catalog and they have the Omron H3YN series that appear to work as a cycle timer. Around $45 plus base. Need to read the specs to tell for sure.They also have H5L and H5S weekly timers that could be used for the TOD timer. But they are around $200.However, I have seen digital lighting timers at Lowes (Intermatic I think) that have tons of options and settings that I think might have 7 day operations. IIRC they where about $40.The TOD timer can then be wired in series with either the cycle timer or a thermostat controller.
i shoulda read it sooner. normally when i install a residential recirc, the feed for you kitchen would come from the 3rd floor shower then the return from that sink to the water heater. then there is only 1 loop. water will always take its easiest path. in larger systems you have to use proportioning valves on the branches of the return but thats when there are more than 30 water supply fixture units or if building sprawls with little plumbing like a mall. all of those tees should have a proportioning valves in them. if you convert to 1 continuos loop the water can only go one way. incedently each branch of a major system is also done this way.
3 story homes are alot more like commercial plumbing. you should also have a seperate vent and drain stack.
the clock can be gotten at any electrical supply. its a sign clock. 40 bux
lawn sprinkler system timer.. ifinite varity...
with battery back up...
use a small contactor at the pump..
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