# grundfos recirculating system



## sparky (Jan 8, 2014)

anybody have any information on how well the grundfos recirculating system works,this is the one one where the pump mounts right on top of the water heater and a tee goes on the last fixture and circulates hot water back thru the cold water line.how much does it mix???do they work worth a crap???i would appreciate the pros and cons of this system if you have installed them or ran across them before.thanks....


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## love2surf927 (Dec 22, 2011)

I've installed them and they do work well. The only issues is that it depends on how the system is piped as to if it will help other fixtures in the area. For example if you mount at the lav it won't necessarily help the shower as much as expected depending on how it's piped but it will still probably help get it there faster. The amount of warm water coming out the cold is just a few seconds at most from my experience and it's not hot because it's mixing with cold water. You can also get multiple four way tees and mount them under several fixtures.


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## sparky (Jan 8, 2014)

love2surf927 said:


> I've installed them and they do work well. The only issues is that it depends on how the system is piped as to if it will help other fixtures in the area. For example if you mount at the lav it won't necessarily help the shower as much as expected depending on how it's piped but it will still probably help get it there faster. The amount of warm water coming out the cold is just a few seconds at most from my experience and it's not hot because it's mixing with cold water. You can also get multiple four way tees and mount them under several fixtures.


thank you so much,i have never installed this type or worked on them,so im blind about it,but it sounds like it might be what im lookin for,the water heater is in a little basement area and the bathroom at the opposite end of the house,takes forever to get hot water there,there is a vanity i can mount the tee into,and the shower is right there with it also,so it sounds like it will work for this particiliar house,thanks so much for your input,i appreciate it very much


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## sparky (Jan 8, 2014)

love2surf927 said:


> I've installed them and they do work well. The only issues is that it depends on how the system is piped as to if it will help other fixtures in the area. For example if you mount at the lav it won't necessarily help the shower as much as expected depending on how it's piped but it will still probably help get it there faster. The amount of warm water coming out the cold is just a few seconds at most from my experience and it's not hot because it's mixing with cold water. You can also get multiple four way tees and mount them under several fixtures.


also love2surf,would it be any better to mount that tee under the house on the hot and cold lines going up to the shower itself???if i put it in the vanity do you think it would help that shower like it should???thanks


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## rjbphd (Feb 5, 2010)

sparky said:


> anybody have any information on how well the grundfos recirculating system works,this is the one one where the pump mounts right on top of the water heater and a tee goes on the last fixture and circulates hot water back thru the cold water line.how much does it mix???do they work worth a crap???i would appreciate the pros and cons of this system if you have installed them or ran across them before.thanks....


Wrong way to pipe it and you don't need any freakin pump if you pipe it correctly!!


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## sparky (Jan 8, 2014)

rjbphd said:


> Wrong way to pipe it and you don't need any freakin pump if you pipe it correctly!!


old old house,no way to get a return like piped back to the water heater,this will have to have a pump if it gets a circulating line at all


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## rjbphd (Feb 5, 2010)

sparky said:


> old old house,no way to get a return like piped back to the water heater,this will have to have a pump if it gets a circulating line at all


Then pipe it correctly by connecting it to the drain side of the heater..


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## sparky (Jan 8, 2014)

rjbphd said:


> Then pipe it correctly by connecting it to the drain side of the heater..


if you dont pipe this particiliar unit like the manufacturer shows then it voids warrantty,i have never installed one like this,just getting feedback from plumbers that have or had dealings with this type system.


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## rjbphd (Feb 5, 2010)

I've delt with all kind of incorrect pump installations... common ones are the ones they follow the DIY sites..


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## love2surf927 (Dec 22, 2011)

rjbphd said:


> I've delt with all kind of incorrect pump installations... common ones are the ones they follow the DIY sites..


Rj with all due respect this system is designed to utilize the cold line from the farthest fixture as the return. There is a 4 way tee that mounts under the farthest fixture and feeds hot back through the cold line to achieve the desired temp. Sparky to answer your question if it's a long run to one end of the house chances are the tee going to the shower is fairly close to the lav so yes it will help, how much will depend on the length and size of the branch that tees off the line feeding the lav to the shower. IMO it will definitlely shorten the time it takes for hot to reach the shower if mounted under the lav, unless they have a system such as a "home run" system where all lines are run individually back to a manifold which is very unlikely if it is an older home.


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## Nevada Plumber (Jan 3, 2009)

I've installed about a dozen of the Grundfos comfort systems. All my customers are happy with them. It really beats dragging a new return line through an attic that doesn't have much room to crawl in.


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## sparky (Jan 8, 2014)

Nevada Plumber said:


> I've installed about a dozen of the Grundfos comfort systems. All my customers are happy with them. It really beats dragging a new return line through an attic that doesn't have much room to crawl in.


I am definetly going to quote this type of system for my customer,thanks to lovetosurf and Nevada plumber for the feedback,i think this will be just what they need for that hot water circulating line/system,thanks guys:thumbup:


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## redbeardplumber (Dec 4, 2012)

You might want to search older threads sparky, there were some negatives, I can't remember what... I don't think they were so negative that you wouldn't install, but some points that will make you more knowledgeable were made in previous threads on this system....

Good luck with the search engine.... It rarely works for me. Lol


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## PLUMBER_BILL (Oct 23, 2009)

sparky said:


> anybody have any information on how well the grundfos recirculating system works,this is the one one where the pump mounts right on top of the water heater and a tee goes on the last fixture and circulates hot water back thru the cold water line.how much does it mix???do they work worth a crap???i would appreciate the pros and cons of this system if you have installed them or ran across them before.thanks....
> 
> 
> SPARKY
> ...


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## Shoot'N'Plumber (Apr 27, 2013)

think of he system your referencing as a "shortcut" now there's nothing wrong with taking the shortcut if its truly the most feasible way, however, if a shortcut were easy it wouldn't be a shortcut. Now I've installed more or these systems than I can count, and for the most part they work fine, obvioisly the more you install the percentage of potential problems arise. It's important to get a layout of the plumbing because if there are any secondary main branches like bathrooms on opposite side of the house you will need to install 2 otherwise only one bathroom will work as expected, also ask the homeowner if they are happy with kitchen sink taking a while as one may need to be installed there as well.


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## BOBBYTUCSON (Feb 8, 2013)

Grundfos is the way to go.it actually works really well. Obviously theres nothing better than a properly plumbed dedicated return line, but grundfos is definitely not a gimmick.the only downside i have ran into is it is more sluggish with houses with out a prv that suffer from low pressure, so adding a pressure booster does help the otherwise sluggish time it would take for the hot water to recirc through the grunfos system.ive never had a callback on a grundfos.


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## Cal (Jun 17, 2008)

I've installed several of these with and as recommended by Grand Hall with the Eternal Hybrid heaters . GREAT and satisfied system ! 
That is my experience and the feedback from my customers .


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## sparky (Jan 8, 2014)

well I installed my first grundfos circulationg pump/system the other day and it worked like charm,i really like them,the ho is really satisfied.


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## PlumberDave (Jan 4, 2009)

The only time I run into these add-on circ systems is when folks have problems in mainly, their showers. It seems like the pressure balance and temp controlled valves do not play nice together with these. I think the little rubber check flapper in the crossover isn't able to handle the pressure difference with a high volume shower valve, so the temp at the shower goes hinky. When I remove the crossover everything is fine. Even better is that the folks got used to a circ system and now want it done right.


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## johntheplumber (Feb 11, 2013)

I have literally installed hundreds of these over the years. I have never had vent one customer call back to complain. I will typically add between 2-4 of the bypass valves. They work wonderful on the eternal hybrids, as long as the hybrid mode is on. I have installed probably 30-40 on the eternals.


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## SSP (Dec 14, 2013)

I concur that grundfos are serious quality professional pumps, and typically our standard preference.

I saw an advertisement at the wholesaler today on a new Grundfos pump line that auto-regulates itself within certain ranges dependent on which settings you utilize. 

I'm up in Canada so these could very well have been in the States or Europe for years, anyone have any experience with these? I only glanced at the poster, sorry for the lack of detail


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## sparky (Jan 8, 2014)

how do you go about setting the timer on these things???seemed pretty complicated to me,so I just left it to circulate all the time.told the ho that if he wanted it to come on and off at certin times he could set it himself.shown him the manual


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## johntheplumber (Feb 11, 2013)

sparky said:


> how do you go about setting the timer on these things???seemed pretty complicated to me,so I just left it to circulate all the time.told the ho that if he wanted it to come on and off at certin times he could set it himself.shown him the manual














Each little dip switch represents 15 minutes. Up is on and down (towards the center) is off.


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## Plumbus (Aug 4, 2008)

johntheplumber said:


> View attachment 30942
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Make sure you get the time set properly.:whistling2:


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## Plumbus (Aug 4, 2008)

SSP said:


> I concur that grundfos are serious quality professional pumps, and typically our standard preference.
> 
> I saw an advertisement at the wholesaler today on a new Grundfos pump line that auto-regulates itself within certain ranges dependent on which settings you utilize.
> 
> I'm up in Canada so these could very well have been in the States or Europe for years, anyone have any experience with these? I only glanced at the poster, sorry for the lack of detail


Saw that a while back myself. Called my Grundfos rep about it. He said the application for a self modulating pump is heating not domestic hot water.


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## rjbphd (Feb 5, 2010)

Aaaaaarrrrghhhhhhhhhhh!~


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## redbeardplumber (Dec 4, 2012)

Relax RJ. It's almost playoff time. Lol..... Sorry sparky... You let it run all the time and left manual with owner??? If I don't know something, I make sure I tell them I'll be back to correct. 

If it's a new system your unfamiliar with... The extra time is called learning. Sorry think you handled it poorly...


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## sparky (Jan 8, 2014)

redbeardplumber said:


> Relax RJ. It's almost playoff time. Lol..... Sorry sparky... You let it run all the time and left manual with owner??? If I don't know something, I make sure I tell them I'll be back to correct.
> 
> If it's a new system your unfamiliar with... The extra time is called learning. Sorry think you handled it poorly...


yea,i didnt do the best on the timer issue,i admit that,i told the ho to let it circulate all the time for one month and see if his electric bill goes up any at all,and if it does,for him to call me back and we would set the timer for him if he couldnt figure out how to do it,(this is my first install with this type pump/system so i admit i dont know alot about them,learned alot on here,thanks)i just really didnt know how to set the dam thing,to be honest with ya


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## johntheplumber (Feb 11, 2013)

sparky said:


> yea,i didnt do the best on the timer issue,i admit that,i told the ho to let it circulate all the time for one month and see if his electric bill goes up any at all,and if it does,for him to call me back and we would set the timer for him if he couldnt figure out how to do it,(this is my first install with this type pump/system so i admit i dont know alot about them,learned alot on here,thanks)i just really didnt know how to set the dam thing,to be honest with ya


It only uses the same amount of electricity as a 25 watt light bulb. So it shouldn't add too much. IMO it's worth the minimal cost to have hot water quickly available at all times. Of course I inform the customer of their choices and allow them to decide.


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## plumbdrum (Nov 30, 2013)

I believe it can work on temp differential also? It's been a while since I've installed 1, but I believe I could work that way

Sent from my iPhone using PlumbingZone


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## JK949 (Mar 18, 2009)

I've had to deal with a few people that didn't seem to understand that warm water returns through the cold line when they put their money down. I explain how they work and that they may need to change some behaviors to work with the system. I do stress that a dedicated line is the best way.


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