Family Chart for Setting Water Heater Timer/ Based on temperature of water 
Meter on water heater The Kwh meter is din rail mounted inside enclosure. Buy 240 volt pass through Kwh meter 2T2502GA beige plastic enclosure 2T2500GA grey plastic enclolsure Resource: Enclosures 
Formula for heating water inside tank: Gallon Per Hour (Electric) = (KW x 3413) divided by (temp. rise x 8.25) or (KW x 414) divided by (temp rise.) Let's say you have 5500 watt elements. let's say incoming water temperature is 65°F and you want to heat tank to 115°, or 40° rise in temperature. 5500 watt or 5.5Kw elements x 3413 = 18771.5 40 degree temperature rise x 8.25 = 330 So in this specific situation, the element would heat 56.88 gallons per hour If you have 4500 watt elements and incoming water temperature is 55°, and you want to heat to 120°, then the temperature rise is 65° 4.5 KW x 3413 = 15358.5 65 degree temperature rise x 8.25 = 536 So one element would heat 28 gallons per hour This number is for EACH element, but does NOT consider heat loss from tank, room temperature, or thickness of insulation etc. Remember, with residential simultaneous tank, only ONE element is ON at one time. Upper element is ON, or lower element is ON, or BOTH elements are off. At no time are both elements on. 
30 Gallon Water Heater
with 3500
Watt Elements 30 x 8.34 pounds per gallon = 250.2 pounds of water <> it takes .000293 Kwh to raise 1 pound of water 1° F (assuming ideal conditions inside tank) 250.2 x .000293 x rise in temperature = Kwh 

Temperature of water at start time 
Raise temperature to 120°  30 Gallon/
3500 Watt Water heater > delivers 3.5 Kilowatts per hour.. Kwh needed to make 30 gallons° hot water 
Set timer to make 30
gallons: (For gas heater, divide times by half) 
Cost per day at ;14˘ per Kwh  Cost
per day: @ 12˘ 
Cost
per day: @ 10˘ 
32°  120°  6.45 Kwh  1 Hour 50 minutes  .74 per day = $22.09 mo  .77  .64 
40°  120°  5.86 Kwh  1 Hour 40 minutes  .67 per day = $20.01 mo  .70  .58 
50°  120°  5.13 Kwh  1 Hour 27 minutes  .59 per day = $17.58 mo  .61  .51 
60°  120°  4.39 Kwh  1 Hour 15 minutes  .50 per day = $15.07 mo  .53  .44 
70°  120°  3.66 Kwh  1 Hour 2 minutes  .42 per day = $12.56 mo  .44  .36 
80°  120°  2.93 Kwh  50 minutes  .33 per day = $10.03 mo  .35  .29 
90°  120°  2.2 Kwh  37 minutes  .25 per day = $7.52 mo  .26  .22 
54°  Approx annual
average outdoor
temperature for northern US states See avertage underground water temperature chart 
65°  Approx annual average outdoor temperature for southern US states 
Any underground water pipe is using geothermal heat from ground to assist water heater 
40 Gallon Water Heater
with
4500 Watt Elements
40 x 8.34 pounds per gallon = 333.6 pounds of water < it takes .000293 Kwh to raise 1 pound of water 1° F (assuming ideal conditions inside tank) 333.6 x .000293 x rise in temperature = Kwh 

Temperature of water at start time 
Raise temperature to 120\°\  40 Gallon/
4500 Watt Water heater > delivers 4.5 Kilowatts per hour.. Kwh needed to make 40 gallons of 120° hot water 
Set timer to make 40
gallons: (For gas heater, divide times by half) 
Cost per day at 14˘ per Kwh  Cost
per day: @ 12˘ 
ost
per day: @ 10˘ 
<32°  120°  8.60 Kwh  1 Hour 54 minutes  1.20 per day = $36.00 mo  1.03  .86 
40°  120°  7.82 Kwh  1 Hour 44 minutes  1.09 per day = $32.84 mo  .94  .78 
50°  120°/td>  6.84 Kwh  1 Hour 31 minutes  .96 per day = $28.73 mo  .82  .68 
60°  120°  5.86 Kwh  1 Hour 18 minutes  .82 per day = $24.61 mo  .70  .58 
70°  120°  4.88 Kwh  1 Hour 5 minutes  .68 per day = $20.50 mo  .58  .48 
80°  120°  3.91 Kwh  52 minutes  .54 per day = $16.42 mo  .47  .39 
90°  120°  2.93 Kwh  39 minutes  .41 per day = $12.31 mo  .35  .29 
50 Gallon Water Heater
with
4500 Watt Elements
50 x 8.34 pounds per gallon = 417 pounds of water <>it takes .000293 Kwh to raise 1 pound of water 1° F (assuming ideal conditions inside tank*) 417 x .000293 = .122181 x rise in temperature = Kwh 

Temperature of water at start time 
Raise temperature to 120°  50 Gallon/
4500 Watt Water heater > delivers 4.5 Kilowatts per hour.. Kwh needed to make 50 gallons of 120° hot water< 
Set timer to make 50
gallons: (For gas heater, divide times by half) 
Cost per day at 14˘ per Kwh  Cost
per day: @ 12˘ 
Cost
per day: @ 10<˘ 
32°  120/td>  10.75 Kwh  2 Hour 23 minutes  1.50 per day = $45.00 mo  1.29  1.07 
40°  120°  9.77 Kwh  2 Hour 20 minutes  1.37 per day = $41.34 mo  1.17  .98 
50°  120°  8.55 Kwh  1 Hour 54 minutes  1.20 per day = $35.91 mo  1.03  .86 
60°  120  7.33 Kwh  1 Hour 37 minutes  1.03 per day = $30.79 mo  .88  .73 
70°/td>  120°/td>  6.10 Kwh  1 Hour 21 minutes  .85 per day = $25.62 mo  .73  .61 
80°  120°  4.88 Kwh<  1 Hour 5 minutes  .68 per day = $20.50 mo  .59  .49 
90°/td>  120°  3.66 Kwh  49 minutes  .51 per day = $15.371 mo  .44  .37 
50+ Gallon Water Heater with 5500
Watt Elements 50 x 8.34 pounds per gallon = 417 pounds of water <> it takes .000293 Kwh to raise 1 pound of water 1° F (assuming ideal conditions inside tank*) 417 x .000293 x rise in temperature = Kwh 

Temperature of water at start time 
Raise temperature to
120° d 
50 Gallon/ 5500 Watt Water heater > delivers 5.5 Kilowatts per hour.. Kwh needed to make 50 gallons of 120° hot water  Set timer to make 50 gallons: (For gas heater, divide times by half)  Cost per day at 14˘ per Kwh  Cost
per day: @ 12˘ 
Cost
per day: @ 10˘ 
32°  120°  10.75 Kwh  1Hour 57 minutes  1.51 per day = $45.15 mo  1.29  1.07 
40°  120°  9.77 Kwh  1 Hour 47 minutes  1.36 per day = $41.03 mo  1.17  .98 
50°  120  8.55 Kwh  1 ;Hour 33 minutes  1.18 per day = $35.91 mo  1.02  .85 
120°  7.33 Kwh<  1 Hour 20 minutes  1.02 per day = $30.78 mo  .88  .73  
70°  120°  6.11 Kwh  1 Hour 6 minutes  .85 per day = $25.66 mo  .73  .61 
80°  120  4.89 Kwh  53 minutes  .68 per day = $20.54 mo  .58  .49 
90°  120°  3.66 Kwh  40 minutes  .51 per day = $15.32 mo  .44  .36 
Use safety grab bar on bathtub Safety grab bar at Amazon Bathtub safety grab bars 
Regular bath uses 13 15
gallons hot water (20 gal water total) Set water heater timer for 4560 minutes for hot bath Resources Compare water heater timers Off peak water heater options Buy: Bathtubs and shower stalls at Amazon 
Fully heated 40 gallon tank gives 2 baths and 1 shower 
Shower uses
6  8
gallons of hot water (10 gal water total) Set water heater timer for 2030 minutes for hot shower Buy: Shower stalls at Amazon Home energy savings books at Amazon 
Clean shower and doors with White vinegar or CLR calcium and rust remover CLR shower cleaner Amazon Shower stalls at Amazon 
See example chart 
Old sizing chart Post 2015 heaters require high tech for sizes over 50 gallon Take showers instead of bath. Save 10 gallons hot water each time. To achieve same hot water consumption as previous heater withut buying more expensive heater install 2 water heaters, cut consumption, maintain heater, turn up thermostat temperature Two water heaters 9 ways to save with water heater Maintain water heater How to adjust themostat Ways to increase hot water Calculate first hour delivery 
For large bathtub, use 80 gallon first hour 
What size water heater?Size chart shows First Hour delivery ratingFirst hour is capacity of tank at peakusage times. For example at night when everybody is taking a shower or bath Increase amount of hot water with changes and maintenance How to adjust temperature How to increase amount of hot water How to maintain water heater Homes with garden tub, whirlpool bath, or oversized tub = first hour 80 gallon 
Avoid oversized bathtubs. It's not cheap to heat all that hot water. Buy a spa. Drive to ocean and support tourism. 
What size water heater for oversize bathtub?Large bathtub / whirlpool tubRecommend 80 gallon first hour delivery Electric: minimum 60to80 gallon size just for that one tub Gas: minimum 50 gallon size just for that one tub Electric heat pump water heaters generally cannot produce enough hot water. Tankless promise unlimited hot water, but temperature of water is 120 F and water in tub may be cool by time tub fills. Cost of maintenance and repairs never pay back. All costs are energy. Troubleshoot Rheem tankless Turn up thermostat on any water heater to increase amount of available hot water How to adjust temperature How to increase amount of hot water Cost to run water heater 
How to install gas water heater Troubleshoot gas water heater Troubleshoot electric water heater 
54°  Approx annual average outdoor temperature for northern US states  
65°  Approx annual average outdoor temperature for southern US states  
See shallow groundwater temperature map  
Read sediment; sediment removal; softened water 
Buy Electronic parts Industrial supplies Tools and home improvement Home and garden Hayward pool Pentair pool Southwire electric 

Buy
Tools DEWALT Black and Decker Stanley SKIL Makita PorterCable Bosch Irwin Hand tools Klein hand tools Fluke electrical testing Dremel hobby tools Campbell Hausfeld air powered Tekton automotive Powerbuilt automotive Saws and saw blades 

Resource: Compare box timers DPDT timers Intermatic Control water heater w/ Zwave 

Resource: Intermatic control centers: and parts Digital control centers and parts Tork control centers and parts Subpanels All control centers and parts Enclosures 

Resource: Programmable timers Countdown timers Off delay timers On delay timers Timer modules Din rail Twin & oneshot Woods Intermatic Tork 

Recirculation systems 
Enter Amazon from
my links Amazon Email: geno03245w@gmail.com My response might end up in spam folder, check email folders Waterheatertimer on Twitter 