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Seisco Water Heaters

water heater gas flex connectors - excellent selection of PVC fittings - electric space heaters
no minimums on our great choice of copper fittings - brass fittings - stainless steel fittings
Rheem tankless water heaters - Chronomite instant flow & instant temp water heaters
more tankless water heaters


Note: Prior to ordering, please check/confirm the temperature rise limits of all brands of instant tankless water heaters to make certain that they will meet your needs. We guarantee that they will heat as the manufacturer states in the specifications, but instant heaters are not for every water-heating application and will only offer the heat rise stated for each model.

Model # RA-11 Electric Tankless Water Heater
Two-Chamber Tankless Water Heater RA-11

Temperature Rise:
75°F @ 1.0gpm
50°F @ 1.5gpm
37°F @ 2.0gpm
30°F @ 2.5gpm

Features:
  • Size:15 3/4" x 10 1/4" x 6 1/4"
  • Heat output (max.): 37,540 BTU
  • Power rating (max.): 11 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 46 A
  • Energy factor: 0.99+
  • Heating elements: 5500 watts x 2
  • Temp. output (dial): 90-130°F
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-11 Electric Tankless Water Heater - 240V $537.78

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Model # RA-14 Electric Tankless Water Heater
Two-Chamber Tankless Water Heater RA-14

Temperature Rise:
95°F @ 1.0gpm
64°F @ 1.5gpm
48°F @ 2.0gpm
38°F @ 2.5gpm

Features:
  • Size:15 3/4" x 10 1/4" x 6 1/4"
  • Heat output (max.): 47,780 BTU
  • Power rating (max.): 14 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 58 A
  • Energy factor: 0.99+
  • Heating elements: 7000 watts x 2
  • Temp. output (dial): 90-130°F
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-14 Electric Tankless Water Heater - 240V $586.57

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Model # RA-18 - Electric Tankless Water Heater
Four-Chamber Tankless Water Heater RA-18

Temperature Rise:
61°F @ 2.0gpm
49°F @ 2.5gpm
40°F @ 3.0gpm
30°F @ 4.0gpm

Features:
  • Size:15 3/4" x 15 3/4" x 6 1/4"
  • Heat output (max.): 61,430 BTU
  • Power rating (max.): 18 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 75 A
  • Energy factor: 0.99+
  • Heating elements: 4500 watts x 4
  • Temp. output (dial): 90-130°F
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-18 Electric Tankless Water Heater - 240V $799.64

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Model # RA-22 - Electric Tankless Water Heater
Four-Chamber Tankless Water Heater RA-22

Temperature Rise:
75°F @ 2.0gpm
60°F @ 2.5gpm
50°F @ 3.0gpm
37°F @ 4.0gpm

Features:
  • Size:15 3/4" x 15 3/4" x 6 1/4"
  • Heat output (max.): 75,080 BTU
  • Power rating (max.): 22 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 91 A
  • Energy factor: 0.99+
  • Heating elements: 5500 watts x 4
  • Temp. output (dial): 90-130°F
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-22 Electric Tankless Water Heater - 240V $807.58

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Model # RA-28 - Electric Tankless Water Heater
Four-Chamber Tankless Water Heater RA-28

Temperature Rise:
95°F @ 2.0gpm
76°F @ 2.5gpm
64°F @ 3.0gpm
48°F @ 4.0gpm

Features:
  • Size:15 3/4" x 15 3/4" x 6 1/4"
  • Heat output (max.): 95,560 BTU
  • Power rating (max.): 28 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 116 A
  • Energy factor: 0.99+
  • Heating elements: 7000 watts x 4
  • Temp. output (dial): 90-130°F
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-28 Electric Tankless Water Heater - 240V $829.42

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Model # RA-32 - Electric Tankless Water Heater
Four-Chamber Tankless Water Heater RA-32

Temperature Rise:
109°F @ 2.0gpm
87°F @ 2.5gpm
73°F @ 3.0gpm
55°F @ 4.0gpm

Features:
  • Size:15 3/4" x 15 3/4" x 6 1/4"
  • Heat output (max.): 109,211 BTU
  • Power rating (max.): 32 kW
  • Voltage rating (nominal): 240 VAC
  • Current rating (max.): 133 A
  • Energy factor: 0.99+
  • Heating elements: 8000 watts x 4
  • Temp. output (dial): 90-130°F
  • No minimum flow activation required
  • Rust & corrosion resistant
  • Power sharing & variable power control technology
  • Microprocessor digital control
  • Built-in DSM utility integration option
  • Small and compact
  • 3/4" plumbing connections
  • Continuous venting
  • High performance polymer nylon chamber material
  • Built-in leak detector and alarm
  • UL 499 approval listing for water heating applications
Model # Description Price & Quantity
RA-32 Electric Tankless Water Heater - 240V $859.88

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Commercial Tankless Electric Water Heaters

Commercial Models - Electric Tankless Water Heaters
Two & Four-Chamber Tankless Water Heaters
Features:
  • Temp. output (dial): 90-130°F
  • Thermistor temperature sensing
  • Rust & corrosion resistant
  • Redundant safety features - Two water level sensors are located at the top of the water heater's chambers to prevent powering on the heating elements if sufficient water is not detected inside the water heater.
  • Power sharing & variable power control technology
  • Microprocessor digital control
  • Continuous venting
  • Service button/LED light/speaker
  • Built-in leak detector and alarm
  • 3/4" electrical conduit connection
  • Heavy gauge steel mounting panel
  • 3/4" non-ferrous inlet/outlet connections
  • Cleanout plates
  • Heating elements - Industry standard 1-1/2" hex head, direct immersion, heating elements utilize PowerShare technology to help eliminate scale build-up and prolong element life far beyond that of tank type water heaters.
  • UL 499 approval listing for water heating applications
  • 5 years manufacturer limited warranty
  • See specifications below
Two-Chamber Electric Tankless Water Heaters
Dimensions: 10-1/4" x 15-3/4" x 6-1/4"
Model # Description Price & Quantity
CA-5 Two-Chamber Electric Tankless Water Heater $618.67
CA-7 Two-Chamber Electric Tankless Water Heater $618.87
CA-9 Two-Chamber Electric Tankless Water Heater $627.63
CA-11 Two-Chamber Electric Tankless Water Heater $638.21
CA-14 Two-Chamber Electric Tankless Water Heater $679.57

Four-Chamber Electric Tankless Water Heaters
Dimensions: 15-3/4" x 15-3/4" x 6-1/4"
Model # Description Price & Quantity
CA-18 Four-Chamber Electric Tankless Water Heater $949.87
CA-22 Four-Chamber Electric Tankless Water Heater $969.46
CA-28 Four-Chamber Electric Tankless Water Heater $984.25

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Specifications for Commercial Models - Electric Tankless Water Heaters
Model CA-5 CA-7 CA-9 CA-11 CA-14 CA-18 CA-22 CA-28
KW Input 5 7 9 11 14 18 22 28
BTU Input 17,065 23,891 30,717 37,543 47,782 61,434 75,086 95,564
Weight (lbs) 15 15 15 15 15 23 23 23
240 V. Amp. 20.8 29.2 37.5 45.8 58.3 75.0 91.7 116.7
# Elements 2 2 2 2 2 4 4 4
Element KW 2.5 3.5 4.5 5.5 7 4.5 5.5 7
# Breakers (240V) 1 1 1 1 2* 2 2 4**
Breaker (amps) 25 30 40 50 30 40 50 30

* Optional: 1-60 amp breaker, ** Optional: 2-60 amp breaker

Recovery (gpm & gph) @ Temperature Rise (F)
Model Recovery 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15
CA-5 gpm 0.38 0.40 0.42 0.45 0.49 0.53 0.56 0.62 0.68 0.76 0.85 0.98 1.1 1.4 1.7 2.3
gph 22.8 24.1 25.6 27.3 29.3 31.5 34.1 37.2 41.0 45.5 51.2 58.5 68.3 81.9 102.4 136.6
CA-7 gpm 0.53 0.56 0.59 0.64 0.68 0.74 0.81 0.88 1.0 1.1 1.2 1.4 1.6 1.9 2.4 3.2
gph 31.9 33.7 35.9 38.2 41.0 44.1 47.8 52.1 57.4 63.7 71.7 81.9 95.6 114.7 143.4 191.2
CA-9 gpm 0.68 0.72 0.77 0.82 0.88 0.95 1.0 1.1 1.2 1.4 1.5 1.8 2.0 2.5 3.1 4.1
gph 41.0 43.4 46.1 49.2 52.7 56.7 61.5 67.0 73.8 81.9 92.2 105.4 122.9 147.5 184.4 245.8
CA-11 gpm 0.84 0.88 0.94 1.0 1.1 1.2 1.3 1.4 1.5 1.7 1.9 2.1 2.5 3.0 3.8 5.0
gph 50.1 53.0 56.3 60.1 64.4 69.3 75.1 81.9 90.1 100.2 112.7 128.8 150.2 180.3 225.3 300.5
CA-14 gpm 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.9 2.1 2.4 2.7 3.2 3.8 4.8 6.4
gph 63.7 67.5 71.7 76.5 81.9 88.2 95.6 104.3 114.7 127.5 143.4 163.9 191.2 229.4 286.8 382.4
CA-18 gpm 1.4 1.4 1.5 1.6 1.8 1.9 2.0 2.2 2.5 2.7 3.1 3.5 4.1 4.9 6.1 8.2
gph 81.9 86.8 92.2 98.3 105.4 113.5 122.9 134.1 147.5 163.9 184.4 210.7 245.8 295.0 368.8 491.7
CA-22 gpm 1.7 1.8 1.9 2.0 2.1 2.3 2.5 2.7 3.0 3.3 3.8 4.3 5.0 6.0 7.5 10.0
gph 100.2 106.0 112.7 120.2 128.8 138.7 150.2 163.9 180.3 200.3 225.3 257.5 300.5 360.6 450.7 600.9
CA-28 gpm 2.1 2.3 2.4 2.6 2.7 2.9 3.2 3.5 3.8 4.2 4.8 5.5 6.4 7.6 9.6 12.7
gph 127.5 135.0 143.4 153.0 163.9 176.5 191.2 208.6 229.4 254.9 286.8 327.8 382.4 458.9 573.6 764.8


Low Temperature Micro-Boiler
Residential Space Saving Tankless Water Heaters

Residential Models - Electric Tankless Water Heaters
Low Temp Micro-Boiler Two & Four-Chamber Tankless Water Heaters
Features:
  • Temp. output (dial): 90-145°F
  • High efficiency compact design provides unlimited heat and/or hot water
  • Microprocessor control
  • Power sharing & variable power control technology
  • Thermistor temperature sensing
  • Heating elements - Industry standard 1-1/2" hex head, direct immersion, heating elements utilize PowerShare technology to help eliminate scale build-up and prolong element life far beyond that of tank type water heaters.
  • Redundant safety features - Two water level sensors are located at the top of the water heater's chambers to prevent powering on the heating elements if sufficient water is not detected inside the water heater.
  • Built-in leak detector and alarm
  • Rust & corrosion resistant
  • Service button/LED light/speaker
  • Continuous venting
  • Cleanout plates
  • 3/4" electrical conduit connection
  • Heavy gauge steel mounting panel
  • 3/4" non-ferrous inlet/outlet connections
  • UL 499 approval listing for water heating applications
  • 10 years manufacturer limited warranty
  • See specifications below
Two-Chamber Electric Tankless Water Heaters
Dimensions: 10-1/4" x 15-3/4" x 6-1/4"
Model # Description Price & Quantity
SH-5 Two-Chamber Electric Tankless Water Heater $739.66
SH-7 Two-Chamber Electric Tankless Water Heater $749.87
SH-9 Two-Chamber Electric Tankless Water Heater $749.97
SH-11 Two-Chamber Electric Tankless Water Heater $799.65
SH-14 Two-Chamber Electric Tankless Water Heater $829.77

Four-Chamber Electric Tankless Water Heaters
Dimensions: 15-3/4" x 15-3/4" x 6-1/4"
Model # Description Price & Quantity
SH-18 Four-Chamber Electric Tankless Water Heater $1029.68
SH-22 Four-Chamber Electric Tankless Water Heater $1047.35
SH-28 Four-Chamber Electric Tankless Water Heater $1065.69

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Specifications for Low Temperature Micro-Boiler Residential Tankless Water Heaters
Model SH-5 SH-7 SH-9 SH-11 SH-14 SH-18 SH-22 SH-28
KW Input 5 7 9 11 14 18 22 28
BTU Input 17,065 23,891 30,717 37,543 47,782 61,434 75,086 95,564
Weight (lbs) 15 15 15 15 15 23 23 23
240 V. Amp. 20.8 29.2 37.5 45.8 58.3 75.0 91.7 116.7
# Elements 2 2 2 2 2 4 4 4
Element KW 2.5 3.5 4.5 5.5 7 4.5 5.5 7
# Breakers (240V) 1 1 1 1 2 2 2 4
Breaker (amps) 30 40 50 60 40 50 60 40

Recovery (gpm & gph) @ Temperature Rise (F)
Model Recovery 65 60 55 50 45 40 35 30 25 20 15
SH-5 gpm 0.53 0.56 0.62 0.68 0.76 0.85 0.98 1.1 1.4 1.7 2.3
gph 31.5 34.1 37.2 41.0 45.5 51.2 58.5 68.3 81.9 102.4 136.6
SH-7 gpm 0.74 0.81 0.88 1.0 1.1 1.2 1.4 1.6 1.9 2.4 3.2
gph 44.1 47.8 52.1 57.4 63.7 71.7 81.9 95.6 114.7 143.4 191.2
SH-9 gpm 0.95 1.0 1.1 1.2 1.4 1.5 1.8 2.0 2.5 3.1 4.1
gph 56.7 61.5 67.0 73.8 81.9 92.2 105.4 122.9 147.5 184.4 245.8
SH-11 gpm 1.2 1.3 1.4 1.5 1.7 1.9 2.1 2.5 3.0 3.8 5.0
gph 69.3 75.1 81.9 90.1 100.2 112.7 128.8 150.2 180.3 225.3 300.5
SH-14 gpm 1.5 1.6 1.7 1.9 2.1 2.4 2.7 3.2 3.8 4.8 6.4
gph 88.2 95.6 104.3 114.7 127.5 143.4 163.9 191.2 229.4 286.8 382.4
SH-18 gpm 1.9 2.0 2.2 2.5 2.7 3.1 3.5 4.1 4.9 6.1 8.2
gph 113.5 122.9 134.1 147.5 163.9 184.4 210.7 245.8 295.0 368.8 491.7
SH-22 gpm 2.3 2.5 2.7 3.0 3.3 3.8 4.3 5.0 6.0 7.5 10.0
gph 138.7 150.2 163.9 180.3 200.3 225.3 257.5 300.5 360.6 450.7 600.9
SH-28 gpm 2.9 3.2 3.5 3.8 4.2 4.8 5.5 6.4 7.6 9.6 12.7
gph 176.5 191.2 208.6 229.4 254.9 286.8 327.8 382.4 458.9 573.6 764.8


Hot Water Heater Scale Inhibitor System

Hot Water Heater Scale Inhibitor System
hot water heater scale inhibitor system
This water heater scale inhibitor system features:
  • 3/4" NPT
  • 6 GPM
  • Cold water feed line
  • Inhibits scale build-up caused by hard water
  • Helps protect piping from corrosion
  • Maintains efficiency and extends life of system
  • Translucent dispenser cartridge allows for convenient detection of remaining scale stopper level
  • Slow dissolve rate for long life and consistent dosing
  • Multi-application design effective on all types of hot water systems-boilers, tankless, and tank-type (gas or electric)
  • Made from FDA CFR-21 compliant materials, suitable for drinking and cooking water and all food applications
  • Replacement cartridges (AP431) are available for these in-line scale inhibitor systems
Description Price & Quantity
Hot Water Heater Scale Inhibitor System $66.10
Replacement filter for hot water heater scale inhibitor system $27.31
Note: Recommended time to change/replace filter cartridge is 6 months.
Purchase a replacement cartridge to have on hand when needed.

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Frequently asked questions about tankless water heaters

questions about hot water heater scale inhibitor "What happens if you don't change cartridges often enough on the Scale Inhibitor System?"
answers about tankless water heaters The original water condition and problem will reappear. Hardness will begin to build up again, which you want to avoid.

questions about tankless water heaters "How does the Hot Water Heater Scale Inhibitor System prevent corrosion?"
answers about tankless water heaters It forms a thin protective layer on the inside of pipes and metal parts. This film or layer is microscopic in thickness and will not build up over time.

questions about tankless water heaters "Is the Hot Water Heater Scale Inhibitor System's active ingredient safe?"
answers about hot water heater scale inhibitor Yes! All ingredients used are 100% pure food grade materials. They are approved by the USDA and meet purity requirements as a food additive by the World Health Organization.

questions about hot water heater scale inhibitor "What are the best reasons to install a Scale Inhibitor System?"
answers about tankless water heaters The system inhibits scale build-up and protects the piping from corrosion, which helps maintain efficiency and extends the life of the system.

questions about tankless water heaters "Will the Hot Water Heater Scale Inhibitor System change the taste or odor of water?"
answers about tankless water heaters No. The active ingredient is colorless, tasteless, and odorless when used as recommended.

questions about tankless water heaters"Will an instantaneous water heater save me money on my utility bills?"
answers about tankless water heaters Yes, in most applications you will see a savings. There are some variables that could reduce the amount you save. One example is you will not run out of hot water, so longer showers could cut into your savings. Also, the cost of electricity, propane and natural gas in your area will affect the amount of money saved. The higher the cost for the energy type used to heat your water, the quicker you will recover the higher initial cost of installing a tankless versus tank style water heater.

Positives:

    You will never run out of hot water. "You want an hour long shower? No problem!"
    Electric units can be installed at the point of use.
    You're not paying energy costs to heat water 24 hours a day.
    They're easy to install.
    Our electric units don't require a T&P valve. (No tank!)
    Installing a tankless water heater will indeed be a bonus to the environment (why should we choose wastefulness when we're talking about finite natural resources)?

Negatives:

    They all need a minimum flow rate & pressure to turn on.
    The faster water flows through them, the lower the temperature rise. So,if you expect to take a shower while the clothes washer is running, you will need to select a unit sized to your hot water flow requirements. (Gas units handle this a little better than electric models)
    Electric units need heavy gauge wire. Example: the 9.5kw must have 8ga wire and a 50amp breaker.
    Gas units need a much larger, special flue pipe and larger gas supply than a conventional water heater.
    At times they can produce very hot water. It's easier to get scalded.
    Gas units are more complicated than a conventional water heater.
    With some brands, parts are hard to find (not a negative if you originally purchase from us, as we like to carry parts for the units that we sell).

Summary:
Tankless water heaters have their place. They're not "the answer" to every hot water need, but if they're used correctly they can be the solution to many of them.


We offer many thoughts (quotes) to ponder, such as:
"Perfection is achieved, not when there is nothing left to add, but when there is nothing left to take away." - Antoine de St. Exupery

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