Hot Water Recirculation Choices

Paul, I don't have an expansion bladder. I see your point - there should be no delay (unless the laws of nature have changed).

I will install the switch on the cold side simply due to much easier access. Your source for the delay off circuit is a good one. I had looked everywhere and couldn't find one. Thanks again.

David,
One more thing: You mentioned that you are having a hard time finding a good Aquastat.

I ordered a White-Rogers 1127-2 strap-on aquastat (cheep on E-bay). I hooked it up next to the pump at the Water Heater (The pump is on the return line at the heater)….and it makes a big difference. It reacts very fast to the changing temp and shuts the pump down quickly. I have a run-timer on the pump and before the new Aquastat the pump was running just under 2 hrs/day. With the new aquastat it seems to be about 20min/day.

I suspect an immersion aquastat would be even better..... but I am happy with the strap on.

prygaard said:

David,
One more thing: You mentioned that you are having a hard time finding a good Aquastat.

I ordered a White-Rogers 1127-2 strap-on aquastat (cheep on E-bay). I hooked it up next to the pump at the Water Heater (The pump is on the return line at the heater)….and it makes a big difference. It reacts very fast to the changing temp and shuts the pump down quickly. I have a run-timer on the pump and before the new Aquastat the pump was running just under 2 hrs/day. With the new aquastat it seems to be about 20min/day.

I suspect an immersion aquastat would be even better..... but I am happy with the strap on.

Click to expand...

I'll keep looking - thanks

If your pipes don't run through the slab in contact with the ground, and they're insulated, I find it hard to believe your gas usage went way up. An occupancy sensor might also work for you to run the pump. That way, it would likely be hot when you wanted to say wash your hands after using the toilet rather than turning the faucet on, then off, and waiting. As soon as you left the room, it would stop. This would require potentially multiple switches, but eminantly possible.

Paul, help

Paul, I received my delay off circuit board today. I'm not sure how to wire this up with just the flow switch and delay.

On the delay circuit board:

Line power to AC In.
AC out to the recirc pump.
SW to the flowswitch.

That's what the diagram shows for the delay circuit. If that is correct, does the delay circuit provide power to activate the flowswitch through the SW terminals?

The flow switch diagram shows a hot line leg going to the common terminal on the switch. That makes sense.

I've seen the photo of your control box but I can't really follow the wiring plan. Thanks again.

davidrw said:

Paul, I received my delay off circuit board today. I'm not sure how to wire this up with just the flow switch and delay.

On the delay circuit board:

Line power to AC In.
AC out to the recirc pump.
SW to the flowswitch.

That's what the diagram shows for the delay circuit. If that is correct, does the delay circuit provide power to activate the flowswitch through the SW terminals?

The flow switch diagram shows a hot line leg going to the common terminal on the switch. That makes sense.

I've seen the photo of your control box but I can't really follow the wiring plan. Thanks again.

Click to expand...

Shazam! it works. I wired it as above and it works great.

That trim pot is really sensitive. At minimum setting it's about a 15 second shut off delay. After turning the trim pot an almost imperceptible amount it goes to a one minute delay.

prygaard,
I just wanted to check in with you and see how your system is working. Any reliability issues? Any changes you would make?

I'll be installing a very similar system in the next couple of weeks and would appreciate any advice from a veteran.

I found the solution that is best for my setup. Redwater Diverter www.redwater.net.au No pumps, no energy use no buttons or timers and purely mechanical. Australian

You are all talking about a hydraulic loop. It should work fine without a circ pump. You only need a 3/8" copper insulated line tied into the drain port of the water heater with a check valve. Heat will naturally rise forcing the loop to flow on it's own. I would not think it would cost a fortune to operate. Once everything is up to temp it should be fairly economical, but I'm no engineer. I have known home builders offer this as about a $500.00 option to the price of a house.

Prygaard,
One quick question:
On White-Rogers 1127-2 strap-on aquastat, which terminals do you use? Red-Blue or Red-White?

Thanks
Sutomo

Red is common, Blue is open on temperature rise, White is close on temperature rise. Looks like you'd use Red-Blue.

http://s3.supplyhouse.com/manuals/1284661726949/39254_PROD_FILE.pdf

I know this is an old thread, but I also solved the problem of controlling the recirculation loop similar to how prygaard describes. I have a flow switch on the cold water intake to the water heater and I have 2 temperature sensors, one on water going out of the water heater and one on the return loop coming back to the water heater. The controller senses when there is flow and turns the pump on until the temperature sensors register the same (within tolerance) temp and then monitors the temp difference to ensure the loop stays hot while hot water is being used. It does take a short while for the pump to heat up the entire loop, but it saves a tremendous amount on gas keeping a loop hot 24/7 or even running the pump on a timer which still runs the pump for 6 - 8 hours a day through the week and longer on the weekends. And it doesn't require any buttons/switches at any water fixture and it turns the pump on even when the dish washer or the washing machine draw hot water. Check it out at http://www.smartrecirculationcontrol.com/.

lehrian said:

<SNIP> Check it out at http://www.smartrecirculationcontrol.com/.

Click to expand...

Looks neat. Would it work without a dedicated return line?

rmk9785e said:

Looks neat. Would it work without a dedicated return line?

Click to expand...

The way I read it, no.

What Reach said. It apparently works by sensing a brief flow of hot water and running hot water through the circulation loop until the loop is full of hot water. Looks like all it does is avoid the requirement for an electrical switch at each fixture. There is still a variable delay in HW availability depending where you are in the loop. Seems to me if you've got the loop, you may as well do it right and run the loop on a timer, but lehrian seems to like it.