we recently did a remodel/addition on a 100 yr old home. we expanded the kitchen and added two bathrooms. we paid a plumber to replumb the entire house and install a recirc pump.
when we finally got around to turning it on (once the weather turned cold enough) we were disappointed to find that the hot water still takes about 20 seconds to reach the kitchen tap. we also found that the hot water at two of the bathrooms is very rapid weather the pump is on or not.
so it seems we dont really need the thing for several of our fixtures and it doesnt work very well for the others.
so my question is. how long is acceptable for the water to become hot with a properly installed recirc loop/pump?
when we complained, our plumber said up to 30 seconds is normal, even with a recirc loop. this seems long to me and would seem to defeat the purpose of even having the thing as you would still be wasting a fair amount of water.
Replies
Is this a parallel trunk system using the cold water pipe as the recirc return line, or a loop system with a dedicated hot water return line?
How far is the kitchen sink from the water heater and is the recirc pump at the kitchen sink?
Is it a switched pump that you turn on just before use, or a constant recirc?
If it's switched at use, did you give it a chance to circulate before opening the tap?
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We had the water recirculator running all night before turning on the kitchen sink in the morning and experiencing the 20-second delay. Does everyone agree that the hot water should be fairly instant at the kitchen tap if the circulator was running all night?To respond to questions people raised, there is a dedicated return line. The kitchen sink is a ways from the hot water heater (the heater is in the basement and not directly under the kitchen on the first floor), but that's why we got the recirculator -- to avoid the delay caused by the hot water traveling a long way to reach the tap.
How far is the sink from the point where the hot water is recirculating? You can have a perfectly functioning recirculator, but if the sink is 20 feet away from the recirculating water then it's gonna take several seconds to get hot water.
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im pretty sure the sink is only about 10-12 feet from the loop.
i think they basically just built the loop a little too far from the sink. not sure why since all the other fixtures in the house seem to have very little delay for hot water to arrive at the tap when the pump is on. our beef with the plumber is why didnt they just make the loop closer to the kitchen sink? it is in the new construction part of the house so access was not an issue. as i said there reply was, it is normal to have a 20-30 second delay in getting hot water at the tap even with the recirc pump on. what we are trying to determine is what do most plumbers/homeowners experience? is 20-30 seconds expected?
The systems I install are as instant as one expects.
The return fitting should always be at the closest point to the fixture, or it defeats the purpose of a recirc system.
We did our kitchen over and my wife was tired of waiting for hot water to come to the sink and would only accept an auxiliary heater under the sink -- I just could not justify
I bought a grundflos pump the size of my fist (has a built in timer and sensor when to turn on) our pump runs 6AM to 9PM but only when the temp drops below a certain point -- when we go to the kitchen in the morning, HW is there in a second.
The pump sends it up the hot side and under the sink is a jumper that sends it back the cold side --> go here to see what I mean http://www.grundfos.com/Web/HomeUs.nsf/Webopslag/PAVA-53MKRN
Seemed hard to believe but it works in our house -- the run to the kitchen is about 90 feet - most of the line is insulated. The only reason it takes a second to get to the tap is because the jumper is about a foot from the mouth of the faucet or we'd have it hot instantly
That seems a little far ... normally it would be right under the sink or right next to the fixture, I think not 12 ft away.
If a recirculator ran all night or even e.g. a minute or two ... you should have virtually instant hot water. It partly depends on how far away the return loop is ... but I think they are usually very close to the fixture.
I'm just starting to install a re-circulating loop in my house.
Primarily I want the loop for the two bathrooms on the other side of the house.
But if it is a top notch installation it will loop to all hot water valves.
I can see how your plumber was just thinking the loop was for the far away valves.
I'm going to put the loop in the crawl space hanging from the floor joists.
But if I just T off the loop and run a pipe over to the valve there will be a delay depending on how close the loop is to the valve.
Ideally the loop would turn and go up in a wall cavity and loop as close to the valve as possible. Or directly under the area of the valve to keep the distance short.
But that means opening up walls. Also, insulating the pipe well inside wall cavities and going through plates would be more of a challenge.
I just had some Armacell pipe insulation delivered that is 2 7/8" in dia for the loop.
7/8" ID for the 3/4" pipe and 1" thick walls. I think it should keep the heat inside the pipes pretty well.
I plan on using this pump powered by PV. http://store.altenergystore.com/Solar-Water-Heaters/Solar-Circulator-Pumps/Dc-Pumps/El-Sid-10B-Brushless-12V-Pump-For-Battery-Applications/p4489/?source=froogle
Anyway, that is the plan.
You're right ... you do need to side track from your beeline to the far end and at least get it under the fixture in the crawl if you need to serve them all. From the floor the the fixture is no big deal. You'll have hot water in seconds. Even in a new install, I think I might consider not going past the floor in your case just to keep it simple. I'd think that would be OK. 'Course when you actually implement what you feel is a good idea often results in the harsh discovery of exactly what the problem with that good idea might be. Ever had that happen?
Oh yea! I think about going the extra mile and doing things the best I can do all the time. But thinking it and doing are two different things.
I will try. That's the best I can do. But if I get in there and it is difficult beyond reason I will back off and settle for less.
Also, when you do something beyond what most people are doing you risk considerable criticism. People can be very competitive with pretty benign things like plumbing.
It would be nice to do one in new construction. All that access! I'm not fond of tight spaces.
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself.Therefore all progress depends on the unreasonable man.
-- George Bernard Shaw
Edited 1/21/2009 9:31 am ET by popawheelie
Edited 1/21/2009 10:51 am ET by popawheelie
I hear ya. Always shoot for high quality/results, but always prepare to comfortably settle for less. If you shoot for less, your result may often be dissapointing. A good attitude, I think.
popa,Seems like a lot of work for what you're trying to achieve.Will your system be hot water 24 hrs/day?
Had a friend on electric hot water do this in a large house and the light bill forced him to change back to regular on demand and wait.Here is a little system you might check out.http://www.chilipepperapp.com/Pete
I don't have to have the pump going 24/7. I can put it on a combination timer and a therm switch.
But I will look at the pump you suggested. I will have to think on it a bit.
I'm not sure what you think is a lot of work in my proposal?
If the pump control is manual ... i.e. you turn the pump on only when you anticipate the need to use hot water ... 20-30 seconds sounds fairly normal. You aren't wasting water ... unless you turn the water on at the same time you turn on the pump. Just turn the pump on before you anticipate needing the hot water.
The alternative is run the pump all the time ... recirc pumps consume pretty small amounts of KWH, but then you have the line losses ... which also can be small if both lines are insulated. Does this loop have a dedicated return line or does it use the cold water? If it uses the cold water, you have to use the pump only when you need hot water.
I would generally advocate using the pump only when needed or during periods of high use (e.g. late afternoon/evening).
Look up Watts recirc. Has timer and thermostatic valve. The valve routes the water from hot water line to the cold water line until finds hot water is hot. Hot water at destination should be almost instant. Timer is so it doesn't recirc all night long. If other locations take too long, install another valve. Note: plumber ignored Mfgr instructions as had installed return piping. Just used timer like older systems, so wasting energy recirc when already hot. Made him change it. Also works for retrofit.
That's the one I was thinking of I think (at least I think it was!). Seems like a straight forward system. Easy to retro and doesn't circulate hot water all the time.
Like Riversong said in his last paragraph. If manual, you will need to give the water time to circulate. All of the water in the lines is cold and needs to be replaced with hot.
The hot water supply should run from fixture to fixture etc.etc. with small return line from the last fixture on the circuit back to wtr. htr. making a complete loop.
And like someone else said, the return may be to far from the sink. Who knows? What does the plumber say.
I always spec. circulating system to have a timer so it is on only active during the hours it is needed. I also include a aquastat so that it turns the pump on when water in the line reaches a preset low temp. and turns off when it reaches a preset high temp. This way the pump is not running all of the time but system is always charged with warm water. This system may use more energy, but you will always have hot water on demand.