# recirculating pump for my tankless.



## Calidecks (Nov 19, 2011)

With the fines coming for excessive water use, I'm thinking about a pump. Even so it would be nice not to wait for the water to get hot. 

Anyone have any suggestions on what kind, a good brand at a decent price? I don't mind spending more for quality. 

Thx in advance.


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## m1911 (Feb 24, 2009)

http://www.faucetdepot.com/prod/Grundfos-UP15-10SU7P-TLC-Comfort-Series-1-25-HP-Recirculator-Pump-%28595916%29-27893.asp


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## Tinstaafl (Jan 6, 2008)

Don't tankless heaters require a certain flow volume before they kick on? That would probably require a different sort of circulator pump--and probably negate any savings you're getting from the tankless.


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## Calidecks (Nov 19, 2011)

Tinstaafl said:


> Don't tankless heaters require a certain flow volume before they kick on? That would probably require a different sort of circulator pump--and probably negate any savings you're getting from the tankless.


They make them for tankless. I went in the manufacturers website and found recommended ones. They claim to save a lot of water.


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## Tinstaafl (Jan 6, 2008)

Water, yes. Energy, not so much.


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## walkinplate (Oct 11, 2014)

Just the other day my plumber was telling me about a new tankless product designed for/with a recirc. 

It didn't make much sense to me to tell you the truth. Seems counter intuitive, but I've learned the hard way not to doubt him when it comes to waste, water or gas. 

I'll see him Monday and pick his brain.


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## Calidecks (Nov 19, 2011)

Tinstaafl said:


> Water, yes. Energy, not so much.


Not really concerned too much about energy. 80% of why I want it is convenience. (Not waiting on the water to get warm). I had the tankless put in to capture the space.


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## builditguy (Nov 10, 2013)

This would really be a question for a plumber. Which I am not. So here's my answer.

It depends on what type of tankless water heater you currently have. I only have experience with Navien. Of course I hire plumbers to do all plumbing work, but this is what we have done in the past. 

Install the re-circulation line. The pump is pretty small and inexpensive. It mounts pretty much anywhere, but usually pretty close to the water heater. Don't forget to put a anti-siphon valve on, after the pump. The pump has an anti siphon pump in it already. Don't trust it.

On top of the pump is a timer. Usually I set the timers to come on about 5 or 6 in the morning, then shut off around 8 or 9. Then set it to come on again about 4 or 5 and shut off about 10. 

This way you are only paying to heat and circulate water when you are using it the most. No reason to be circulating water all day long when nobody is home. Of course this will vary depending on the residents of the house.

Here is the problem with my reply. I can't remember the name of the pump. It's small, red, and has the timer on top. The timer has a tinted plastic cover.

Personally I wouldn't have the re-circulation line. What you save in not having to wait for hot water will be eaten up with spending money on gas to heat the water. The pump doesn't use much electricity.

I don't have alot of examples, but I know one customer had to wait 22 seconds for hot water to get to the second floor. Without the re-circulation pump.


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## loneframer (Feb 13, 2009)

The tankless systems I've seen with a recirculator had an electric heating element on a T-stat to keep the water in the loop hot.


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## flashheatingand (May 3, 2008)

Which fixtures are you have an issue with? All? Or, are there fixtures that are closer which aren't so bad?

As mentioned, there are switching devices in which you can activate the heater before you open the hot water valve at the fixture.


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## Calidecks (Nov 19, 2011)

Read an article that the average home wastes 12000 to 15000 gallons of water per year just waiting for the water to get hot. That's significant.


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## Inner10 (Mar 12, 2009)

Californiadecks said:


> Read an article that the average home wastes 12000 to 15000 gallons of water per year just waiting for the water to get hot. That's significant.


If you have a water usage restriction I suppose it is.


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## Calidecks (Nov 19, 2011)

Inner10 said:


> If you have a water usage restriction I suppose it is.


We don't have a restriction other than if your caught wasting it you can get a fine. Like washing your car without a nozzle. However, we get an allotment for a tiered price, once we go beyond that allotment the price tier jumps significantly.


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## flashheatingand (May 3, 2008)

It is a lot of wasted water, which, is disturbing (at least to me). I make sure customers are aware of the wasted water thing. If the unit is centrally located, not so bad, but...

BTW, Is there a way to determine how the water is folowing, direction-wise? For example, (trying to use electrical terminology, and hoping the same applies in plumbing) all hot water is run in parallel from the w/h... Whats to say that when you open the kitchen sink valve, the "static" water from the bathroom piping goes through the faucet before the hot water from the tankless unit?


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## Calidecks (Nov 19, 2011)

I've been in contact with my plumber. I'm going to turn it over to him.


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## flashheatingand (May 3, 2008)

Yeah, that wasn't an end user question. Just hoping one of the plumbers here could provide that info.

But, if you put a switch in, lets say the master bathroom, once you get hot water in the lines, it shouldn't be so bad for the other fixtures.... Maybe install a controller to activate the pump once every forty five minnutes for about three min? 

You see where I am getting.


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## flashheatingand (May 3, 2008)

builditguy said:


> This would really be a question for a plumber. Which I am not. So here's my answer.
> 
> It depends on what type of tankless water heater you currently have. I only have experience with Navien. Of course I hire plumbers to do all plumbing work, but this is what we have done in the past.
> 
> ...


I think the key is to keep the water in the lines hot, so that when one washes their hands (bathroom use), or rinse off a plate or whatever, the water isn't outright cold. I would put the pump in the furthest location possible, to make sure the lines are "always" hot.


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## m1911 (Feb 24, 2009)

flashheatingand said:


> Yeah, that wasn't an end user question. Just hoping one of the plumbers here could provide that info.
> 
> But, if you put a switch in, lets say the master bathroom, once you get hot water in the lines, it shouldn't be so bad for the other fixtures.... Maybe install a controller to activate the pump once every forty five minnutes for about three min?
> 
> You see where I am getting.


hmm... kind of like a pump with a timer, like the one I posted in the link above...


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## flashheatingand (May 3, 2008)

Exactly. But the difference is that most timers will go on when you wake up, or return home. What I suggest is that they have it setup to go on periodically, say every 1.5 hours for about three minnutes throughout the day.


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