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2014

Recirculation system

Taco recirculation systems  vv
Taco
Install pump at water heater
Install crossover under sink
Choose timed or thermostat operation
Plug into 120V outlet
1 year warranty with receipt
Buy:
Taco recirculation systems
Resource:
General Taco manual
General manual
Grundfos recirculation systems
Grundfos
Install pump at water heater
Illustration shows typical water heater model
Install crossover under sink
Choose timed or thermostat operation
Plug into 120V outlet/ draws 1/4 amp
2 year warranty with receipt
Buy:
Grundfos recirculation systems at Amazon
Replacement crossover valve
Cast iron flange set for flanged pumps
Resource:
General Grundfos product manual
Can use on tankless 0-9 GPM
How to choose proper circulator pump
watts recirculation systems
Watts
Install pump at water heater
Install crossover under sink
Choose timed or thermostat operation
Plug into 120V outlet
1 year warranty with receipt
Buy:
Watts recirculation systems
Replacement crossover valve
Watts sensor valve kit
Resource:
Watts recirculation system manual
Do not install on tankless
Laing recirculation systems
Laing Thermotech
Install under sink/ buil- in crossover valve
Pump and crossover built into same unit
Choose timed or thermostat operation
Plug into 120V outlet
2 year warranty with receipt
Buy:
Laing recirculation systems
Laing recirculation pump for tankless
E10 autocirc for tankless
Resource:
Autocurc manual
ACT 909 tankless recirculation pump manual
E10 autocirc manual
Laing thermotech

Larger image 
Add air vent to keep air out of line will prolong life of pump
Keeps air out of water line
Smoother flow, less noise

Buy air vent:
Air vent/ 1/4" pipe thread at Amazon
Air vent/ 1/4" pipe thread at Amazon
Crossover valve
Buy:
Replacement crossover valve
Watts sensor valve kit
Applies to Taco, Grundfos and Watts. Does not apply to Laing
Crossover valve installs under sink, and allows hot water to circulate from hot side to cold side. Purpose of crossover valve: When recirculation pump is ON, the crossover valve opens and lets hot water circulate back to water heater through the cold water line. Immediate hot water is available at the faucet. When you turn on cold water at the faucet, the crossover valve closes, allowing cold water to enter the faucet.
Note: Cold is not available immediately at the faucet.
Re-circulation install/ maintenance tips
Troubleshoot recirculation pump
Cold flashes with recirculation system

1 horsepower = 756 watts.
Recirculation systems are rated 1/25 Hp  
 1/25 Hp motor = 30.6 watts  
30.6 watts divided by 120 volts = .255 amp
Less than 1 amp
Recirculation system will not overload any circuit

Troubleshoot recirculation system

Electrical requirement/ 1 amp

Hot water recirculation system
Larger image

How water heater recirculation system works 

Part I:  Laing Pump OFF

Hot water re-circulation system with timer turned off

Cold water available immediately, but wait for hot water.

Water- savings estimate of 15,000 gallon per year is promotional foolery: this amount equals 41 gallons per day or 2 full bathtubs of water per day.

Test your home: put empty gallon can under tub spout and see how much water is wasted waiting for hot water. Use water for plants.
Buy:
Laing recirculation pump with timer at Amazon
Auto circ at Amazon
c
Re-circulation system
Larger image

How water heater recirculation system works

Part  II: Laing Pump ON

Re-circulation system with timer turned on.

Hot water available, but wait for cold water.

Timer saves energy compared with recirculation system that runs full time.
Autocirc uses timer, but also turns off when temperature reaches 95, and turns on when water temperature drops to 85.

Buy:

Laing recirculation pump with timer at Amazon
Auto circ at Amazon
Recirculation systems Amazon
Grundfos recirculation at Amazon
Taco recirculation at Amazon

Recirculation in tank
See entire Auto-circ system

Water heater temperature below 140F

Keep Water Heater Temperature Below 140F (60C):

High temperatures cause calcium and magnesium to come out of solution and create solids. These solids can damage pump and reduce water heater efficiency.
Can cause early water heater failure
Resources:
How to adjust temp of water heater
How to maintain water heater
Temperature needed to kill bacterial 140F

Water temperature inside pipe

When using thermostat operation, the pump turns ON automatically when temperature inside pipe drops below 85 degrees and then turns OFF when water temperature reaches 95 degrees F.
When using Timer, the pump runs for specified amount of time. So if water heater holds very hot water, the full tank temperature will circulate 
Recirculation crossover valve

Recirculation crossover valve

Install crossover valve under sink with Hot on left and Cold on right
If this is reversed, then recirculation system will not work
Crossover valve is one-way check valve... lets water through one direction, and then closes when water tried to go other direction.
If recirculation has stopped bring hot water, but the pump is working, then replace crossover valve.
Buy:
Replacement crossover valve
Watts sensor valve kit
Resource:
Example illustrations of installation
Grundfor recirculation system installation

Install pump upright on hot pipe

Install recirculation pump in vertical position on Hot water line.
Which pipe on top of water heater is Hot? 1) Usually the cold line has shut off valve. 2) Top of tank also has H and C markings. 3) Turn on Hot water tap for few moments and use hand to check which pipe feels hot.

Pump installed sideways will not work

Resources
Typical plumbing diagrams
Installation manual with photographs
Grundfos circulation timer
Larger image
Grundfos installation manual
General guide for setting timer

Choose: Timer or thermostat operation?

Choose between 'Timed' operation or 'Thermostatic' operation
Use slide switch located on timer dial.

Choose timer and Program specific times: Move slide switch to timer.
Using timer, the recirculation system runs specific times of day
Timer must be reset after power outage

Or choose Thermostat operation, Move slide switch to ON.
Pump runs whenever temperature inside pipe drops below 90 degrees

To turn off the system, slide switch to OFF
Resources:
General guide for setting timer

$

Timer or thermostat?

Timer can save money if scheduled carefully.
Thermostat operation runs throughout the day. Hot available any time
Cost to operate recirculation pump?
Using the timer and running Autocirc 1 hour a day costs between $11 and $17 per year to operate.
Run autocirc 2 hours a day is $22-34 per year.
Run 12 hours a day costs $11-17 per month, or $132-204 per year.
This includes pump operation and additional time that water heater operates. See calculations

Cost to operate

 
See larger

Direct return/ probably saves money

Does not use cold water line
Requires dedicated return line connecting to water heater drain port
Saves money since water is not wasted waiting for cold to arrive

Direct return connects to water heater drain port.

Resources:
How to remove drain valve
Different type of water heater valves
How to flush water heater

Swing check valve

Swing check valve

Check valve that swings open when water passes one direction.
And swings closed when water tries to pass other direction.
One way valve: Lets water pass one direction, but not other direction

Why is this important?

Recirculation system loop can draw cold water into hot pipe causing cold flashes during shower. This occurs during heavy use periods.
Read more
Bad swing check valve can cause crossover, where cold enters hot pipe and hot water never arrives at faucet: Crossover
Swimming pool, or outdoor ponds: If water hose is left in pool or pond or puddle of water, then water use inside home can draw this unsanitary water back through water hose and into home water pipes. Install swing check valve. Do not leave hoses on ground. Or in pool.
Buy:
Swing check valve at Amazon


    
Larger image

I. Other Hot water option for sink

D'Mand / requires additional water line

Push-button starts recirculation system/ quickly brings hot water to faucet/ no interuption cold
Objective: Water circulates to faucet quickly when activated with push button
Any recirculation pump can be set up in this manner
Connect pump to water heater drain valve opening
Cold is available immediately at tap/ no wait for cold
Buy:
D'mand At Amazon
D'mand push button at Amazon
Resource:
D'Mand recirculation system manual
Wireless interface instructions
How to replace water heater drain valve
under counter water heater

II. Other Hot water option for sink

Point of use water heater

115 Volt, 2-1/2 Gallon point of use heaters available at most home centers
Connect heater to cold water line
Use switch or timer
Buy:
Point of use water heaters at Amazon
Resources
Under-counter water heaters, manuals, and installation
How to increase amount of hot water
Pot heater
Pot heater/ hot water dispenser
Objective: Fill pot for hot water at any sink
12" tall heater heats plugs into 115V outlet
Dispenses 2-3 liters hot water into cup or sink
Use switch or timer
Buy:
Hot water dispenser / pot heater at Amazon
Sunbeam hot water dispenser
hot water dispenser
Hot Water faucet/ dispenser
Objective: save water, save energy
Point of use hot water
Buy:

Kohler hot water faucets at Amazon
Franke hot water dispenser at Amazon
Kitchenaid hot water dispenser

III. Other Hot water options for sink

Pot heater or hot water dispenser


Autocirc timer dial

Resources:
Larger Autocirc image
Auto circ installation manual
Taco 265-3
Larger

Taco 265 DIGI timer

Resources:
DIGI cross reference w/ FM1D
DIGI 240V manual
Taco timer sell sheet

Buy:
Taco timer at Amazon
Taco recirculation at Amazon

Off delay timer for recirculation system
Off delay timer for recirculation system
Push either button to activate delay timer sequence
Another wiring example using push button -or- ST01 programmable timer to start delay

Operate recirculation system remotely from 1-2-3+ different locations

How it works:
Buy delay timer and base
Connect 120volt Hot and Neutral wires to base as illustrated.
Buy thermostat or bell wire and connect to push buttons as shown
The push buttons receive no voltage or power... do not connect to power source.
Plug timer into base. Choose delay time from .05 seconds to 999 seconds
Push doorbell button. Activates timer.
Timer turns ON and begins countdown.
Pump turns ON and runs until countdown stops. Countdown is off-delay.
When countdown expires, timer turns OFF, pump turns OFF.

Buy project materials:
Example 50' thermostat wire at Amazon
6A855 Solid State timer at Amazon
11-pin plug-in base at Amazon

Push button plate Amazon
Resources
Other countdown timers
More off delay and pin timer illustrations
6A855 Manual
Grundfos website
Grundfos assorted manuals

Grundfos service centers
Terminal strip and capacitor replacement/ pdf
Sample manuals below:
UP-018
UP-043 installation photos
UP-042
UP-053
UP-035
UP-092
Choose pump size sheet
Grundfos product list
Grundfos 24 hour programmable clock
Grundfos clip-on thermostat control

Grundfos contact us

Laing AutoCirc Pump residental selection guide
Laing ACT install operation manual
Laing E1 E3 E10 series installation
Laing E1 Replacement Parts
Taco recirculation pumps manual
Taco.com
Taco timer sell sheet
Taco analog/digital timer install/program manual
Taco timer image

Troubleshoot recirculation pump

Misc manuals and links/ Resources

Buy:
Grundfos recirculation pumps at Amazon

Will recirculation pump work on Tankless heater? Yes 4 GPM

If recirculation pump is rated maximum 4 gallon per minute, then assume it will work with tankless when everything is new and running smoothly ... and distance is not too great, and not too many elbows, not too many restrictions in the line, etc

Yes if you select correct recirculation pump.
   Tankless water heaters require minimum flow rate to activate burner, so more powerful recirculation pump is needed.
Laing UCT-909 Tankless AutoCirc is used for Tankless Buy At Amazon  Resource: Product Sell Sheet and specs
Grundfros RCP-96 Recirculation pump for Tankless 145 psi.; 0-25 GPM At Faucet Depot
Resources:
Rheem tankless recirculation illustation
Rheem tankless recirculation illustation 2
Rheem tankless point of use illustration
Rheem tankless recirculation illustration

   Read tankless manual thoroughly for minimum flow rate since flow rate appears in every tankless troubleshooting section.
   Flow rate and performance figures apply only when Tankless unit is new.
   Tankless cannot be exposed to hard water or parts will fail.
   As tankless ages, expect problems that are difficult to diagnose and expensive to repair.
   Re-circulation pumps are also susceptible to hard water and affects of age.

Read Bradford White side-by-side tankless vs tankless test results: "Tankless falls short of payback and cannot be exposed to hard water.'
Read ConsumerReports.org side-by-side test results
Pro-n-con tankless heater
Read research pdf on Tankless/Tank efficiencies and softened water: Tankless cannot be exposed to hard water or parts fail 2 years.

How much does it cost to operate Autocirc?

Using the timer and running Autocirc 1 hour a day costs between $11 and $17 per year to operate.
Run autocirc 2 hours a day is $22-34 per year.
Run 12 hours a day costs $11-17 per month, or $132-204 per year.
This includes pump operation and additional time that water heater operates.

Calculate cost of running recirculation system

Autocirc is 33 watts each time motor operates
Timer runs 2 half-hour periods per day > yearly cost for re-circulation is $11-17 at Today's Rates

Two factors affect cost:

1) Pump cost: Pump uses approx 30 Watts = .030 Kw
Pump runs 1 hour per day = .030 Kwh per day
365 days x .030 Kwh = 10.95 Kwh per year
10.95 Kwh x Todays Rate 10 per Kwh (expect 30 tomorrow)= $1.95 per year

2) Water heater cost from re-heating water:
Amount of water: 1.2 gallons per 100 ft 1/2'" pipe (see calculation to right)

Amount of wasted heat:
Hot water travels to faucet anyway, so waste equals return length of pipe
Exact calculation would factor insulation, temperature of water, effect of home HVAC, efficiency of water heater, water heater thermostat setting, cost of energy.

Additional water heater Cost: Reheating 1-2 gallons uses .2 Kwh of electricity per event See chart
2 events per day x .2 Kwh  x 365 days per year = 146 Kwh per year
146 Kwh x 10 per Kwh = $15 per year for electric heater, $9 for gas

So $9-15 per year for reheating + $2 to run pump = $11-17 per year for re-circulation system that runs 1 hour per day assuming new equipment and optimal conditions, and today's low energy prices.

Read more
Calculate gallons inside 100' pipe:
1 gallon = 231 cu inches
Inner diameter of 1/2 pipe .54" so r radius = .27"
Area = πr

A = 3.14 x .27 x .27 = .229 sq in
100 ft = 1200 in
1200 in x .229 sq in = 274 cu in
274 cu in
231 cu in per gallon = 1.2 gal

3/4" pipe: r radius .37"
A = 3.14 x .37 x .37 = .429 sq in
100 ft = 1200 in
1200 in x .429 sq in = 514 cu in
514
cu in 231 cu in per gallon = 2.2 gal


How to install gas water heater

How to clean water heater

Troubleshoot electric water heater

Programmable water heater timer on wall

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Resources:
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Troubleshoot gas water heater
Troubleshoot electric water heater
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