Hot water recirculators

Hi all,

I have an existing building where we are doing a couple of things at once.
1. remodel small bath
2. replace entire house polybutelene with PEX
3. install hot water recirculator

The majority of the poly is accessible through an unfinished basement, so easy to replace. The longest run is to the small bath over a garage, and we've already replaced that poly (first) while tearing up and redoing the bath.

I have installed a hot water return line for that run to the small bath, and intend on installing another hot water return for the run going the opposite direction for the master bath.

So, to my question about hot water recirculators.

All of the hot water recirculators I seem to have access to as a consumer, is for existing builds in which they don't install a return line, only some sensor under the furthest run.

However, I have future plans - we live in a cold climate and I want to not only install solar hot water but also a radiant heat system - hence the hot water return line now. Not to mention that both runs return line hardware is cheaper than a single sensor.

So...to the question - can I use these hot water recirculators that want a sensor, and utilize my hot water return for them, or do I have to get to someone who has access to pumps that are typically used in new building (and for sale to contractors)?

These are the pumps I'm looking at (want one with a timer)

https://smile.amazon.com/s/ref=nb_s...&sprefix=hot+water+recirculating+pump,aps,227

Thanks for your time.

If you do not have a return line then you will need to buy a grundfus comfort series pump or a metland on demand pump this will help pull the water faster

why do you want to control the pump with a timer ?

this will mean your pump comes on and wastes power if you are not home.

i would suggest a taco circ pump and control it by the light switch in the bathroom

when you enter, turn on the light, water circs, when you leave, turn off light it stops

https://www.amazon.com/Taco-007-F5-Cast-Iron-Circulator/dp/B000J3XLWC/ref=sr_1_12?ie=UTF8&qid=1466687276&sr=8-12&keywords=hot+water+recirculating+pump


if you have 2 bathrooms, use a 3 way switch and a extra hot from switch to switch

frodo said:

why do you want to control the pump with a timer ?

this will mean your pump comes on and wastes power if you are not home.

i would suggest a taco circ pump and control it by the light switch in the bathroom

when you enter, turn on the light, water circs, when you leave, turn off light it stops

if you have 2 bathrooms, use a 3 way switch and a extra hot from switch to switch

Click to expand...

If you use ON/OFF Light SW control, you have to have a switch anywhere there are faucets that you want immediate hot water, correct? 3 baths and kitchen?

I would rather have a system that uses a flow sensor and that sensor(s) activates the pump when water flows through it and stops when the flow ends.

rediranch said:

Hi all,

.

I have installed a hot water return line for that run to the small, and intend on installing another hot water return for the run going the opposite direction for the master bath.

Not to mention that both runs return line hardware is cheaper than a single sensor.

Click to expand...

i give my opinions based on the information given to me by the op.
in this case, the op has stated, he wants a circ line to his master and small bath.
a circ line is not an instant hot system, if the kitchen is close to the circ line it will have hot water in a timely fashion.
same as the shower in the master bath and tub in small bath will .

be very carefull in the wording you use.
if yo tell a client you are installing a recirc line and tell them they will have immediate hot water
you have just bought your self a bucket full of grief.
they will expect instant hot water
that is something you can not deliver with a circ line

Frodo is right. A recirculation system will not give you instantaneous hot water generaly. A recirculation system in a Comercial building is there due to the long runs of pipe. The pump is generally connected to an auqastat that senses the temp of the pipe. Temp drops pump comes on til it senses the set temp in the pipe. Helps keep water in hot water pipe warm to where you don't wait an hour for hot service. I've never put one in a resedintual home before. What is trying to be achieved by adding the recirculation line?

Yes, we understand this is not an "instant scalding hot water" system.

Reasons why we want the re-circulation system:

We live in a cold climate, on a well. The water coming out of the pressure tank is around 55, and if the pump recently cycled it can be colder.

In the summer that temp feels just fine when turning on a faucet for washing hands, in the winter, it feels like freezing water.

The sink and bath that is closest to the hot water heater can take 30-40 seconds to start to warm. The furthest bath takes 40-50.

We also have a septic system that has to handle all that extra water that is wasted while trying to get the water at least warm if not hot.

While we are on a well and don't have a monthly charge for water, our county threatens us now and then to actually use the volume gauges that have to be installed on all well inlets and charge us for it.

Eventually the plan is to convert to solar hot water, which will require a large holding tank. Then after that we want to tap into the re-circulation system that we are trying to put in now, in order to utilize radiant heat.

Right now we have a natural gas water heater. Our gas bill is around $35/month ($10 of that is a monthly service charge!) and we have a gas stove and dryer, i.e., the cost of heating water isn't the driver here, nor should it be costly for a re-circulation pump.


Answer to some of the posted questions:

Why do we want a timer? Recirculating water when not in use is a waste of resources. I want it to come on at a specific time in the morning and stop recirculating at a specific time at night.

Why not a light switch? That initial turn on in the morning would put us right back in the boat we are in now - no hot or even warm water for the time mentioned above. Most likely with all the senior moments we are having more and more often, that switch would be forgotten and the system would run when we don't need it to (at night). Now, a switch could be an option to shut the system down if we leave for a weekend or something, if the pump has no vacation mode.

I fail to see the purpose of a sensor to tell the system when to send hot water - that seems to me to be the same situation we are in now - turning on the faucet and waiting for hot water.

Yes, the master bath feed feeds the kitchen as well (and the washer/dryer but that's not important), so there's only two branches from the hot water heater.

BTW, thanks for your input. We believe we have thought this through but understand that we might not have thought of all the options.

plumb_bob_square_pants said:

Frodo is right. A recirculation system will not give you instantaneous hot water generaly.

Click to expand...

I think what the OP was trying to convey is that he was tired of waiting for hot water at the faucet(s) and the waste and costs it presents.

A recirculation system in a Comercial building is there due to the long runs of pipe. The pump is generally connected to an auqastat that senses the temp of the pipe. Temp drops pump comes on til it senses the set temp in the pipe. Helps keep water in hot water pipe warm to where you don't wait an hour for hot service. I've never put one in a resedintual home before.

What is trying to be achieved by adding the recirculation line?

Click to expand...

Quicker hot water delivery at the faucet(s).

rediranch said:

I fail to see the purpose of a sensor to tell the system when to send hot water - that seems to me to be the same situation we are in now - turning on the faucet and waiting for hot water.

Click to expand...

The purpose of the flow sensor is as the purpose of an ON/OFF switch or a motion detector, to initiate the pump without having to depend on a light switch/motion detector for those occasional instances where one may be required to either crouch or low crawl into the facilities.

-On Demand Recirculation Pump Control-

How did this turn into a pi$$ing contest...

Are you planning on insulating you hot and recirculation line to preserve the heat?

rediranch said:

Why do we want a timer? Recirculating water when not in use is a waste of resources. I want it to come on at a specific time in the morning and stop recirculating at a specific time at night.

Click to expand...

KULTULZ said:

Correct. This method will give closest to immediate hot water as the pump is pumping at all times.

Click to expand...

ADDENDUM-



Please allow mw to interject...

It will not run continually but be cycled ON/OFF by the aquastat, i.e. as the aquastat sees a certain drop in recirc line temp, the pump will come on until the desired temp is realized.

And then, the complete system can be put on a timer to deactivate it at night.

KULTULZ Continues said:

Also, a timed pump can be staggered so as when the aquastat senses dropping water temp in the circuit, it will restart until the circuit is hot again.

Click to expand...

I think this method was where you were going.

KULTULZ said:

The purpose of the flow sensor is as the purpose of an ON/OFF switch or a motion detector, to initiate the pump without having to depend on a light switch/motion detector for those occasional instances where one may be required to either crouch or low crawl into the facilities.

-On Demand Recirculation Pump Control-

Click to expand...

I came home last night after attending my hUkkEd oN FoNIX - wuuRqx 4 mee remedial reading class and re-read the instruction sheet for the system I referred to. They want you to as you enter the BR turn the hot water valve on/off to initiate the pump...

I think a motion sensor would be better...

plumb_bob_square_pants said:

Are you planning on insulating you hot and recirculation line to preserve the heat?

Click to expand...

Yes. Since I'm just a consumer, I only have access to Home Depot so I will be buying the Armaflex pipe insulation that is like $1/ft and seals, not the Styrofoam.

OK, have some updated information. Long story short, I got two pump models from a local plumbing wholesaler (that's part of the long story) and got to discuss it with them on the phone. All three of these pumps require a hot water return line (which is what I couldn't figure out on my own).

Grundfos
UP1016BUATLC - discontinued but readily available, has 24/7 timer
- has built in timer
- can run by maintaining temp in hot line
http://moderncomfort.grundfos.com/media/517169/comfort_pump_brochure.pdf

UP1016APMBULC - smart pump, 3 modes
- runs constant
- can run by maintaining temp in hot line
- smart sensor - learns your schedule and tries to run when it thinks it should
http://us.grundfos.com/content/dam/GPU/Products/up10/98532861_0614_UP Series_DB_US_Internet.pdf


Taco
003BC4PMP - timer
https://www.taco-hvac.com/uploads/FileLibrary/101-066.pdf

It looks like the Grundfos smart pump is designed for radiant heating systems and a secondary use would be hot water recirculation systems.

I don't like the idea of the smart sensor becuase our house is anything but regular, I think it would confuse the heck out of the pump.

The supplier said that based on his knowledge, the Taco is more expensive to run than the Grundfos.

OK, turns out a neighbor has a recirculation system on a newer home and let me come over and check his out. His home is pretty large, and was built with solar hot water, a recirculation system, and radiant heat.

He is using the Grundfos UP1016BUATLC, the one that was discontinued recently.

He had it using a timer, but then he changed it to be on a light switch as well.

Based on all the information at this time, I believe I'm going to go ahead with the newer Grundfos smart pump and use the feature that keeps the water at a certain temp. In the future I may either wire it to a switch to avoid the unecessary running, or hook it up to a large electric timer.

Thanks for everyone's input.

the rubber tx or armaflex insulation,

get a small can of contact cement, that is what the cool kids use to join it

then..miter your 90 degree cuts, and glue the butt ends together

rediranch said:

I don't like the idea of the smart sensor becuase our house is anything but regular, I think it would confuse the heck out of the pump.

Click to expand...

Yeah, forget I posted that. The light switch would make more sense. If one has the skitters I doubt he/she/it/mutant is going to have time to play "turn the knobs"...

..................

Thanks for the illustration, those always help.

Why not consider a small tankless heater near each fixture. It will heat your water until the hot water arrives from your main DHW source and then shut off.