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Flo-Thru Heater Assembly, 4.0 KW, 15" Caldera & Coleman Spas, 20-00318
Was: $211.99Now: $176.95 -
SpaShopper
Gecko Spa Hot Tub S-Class Heater 5.5kw w/ Pigtails and Gasket, SSPA How To Video
MSRP: $259.95$223.95 -
SpaShopper
Cal Spa Complete Heater 4.0kw Retrofit XL Heat Exchanger Upgrade Video How To
MSRP: $299.95$269.95 -
SpaShopper
Gecko Spa Hot Tub S-Class Heater 4.0kw Soldered Tab Style with Gasket SSPA How To Video
MSRP: $259.99$212.95 -
SpaShopper
Heater FloThru Tube Complete ACC or Acura Electronics 1000 or 2000, 15", 230v, 5.5kW
MSRP: $329.95$269.95 -
SpaShopper
Gecko Spa Hot Tub S-Class Heater 4.0kw w/ Pigtails, Pressure Switch and Gaskets, SSPA How To Video
MSRP: $249.95$223.95 -
Heater Assemblies, Flow Thru
Heater assemblies, flow thru are complete, ready-to-install electric heating units designed for hot tubs and spas. Water flows directly through the heater manifold (typically stainless steel or titanium for corrosion resistance), where the element heats it efficiently and safely—preventing dry firing via integrated sensors or switches.
This category features a full range of replacement flow thru heater assemblies compatible with leading brands including Balboa (M7 systems), Gecko (in.ye/in.stream), HydroQuip (universal and OEM-style), Sundance, Jacuzzi, Cal Spa, Watkins/Caldera, Therm Products, and more. Assemblies come in various specs: 4.0kW to 11kW ratings, 120V/240V, 15" or longer lengths, 1-1/2" or 2" plumbing unions, low-flow/high-flow designs, and options with M7 dual temp/hi-limit sensors, pressure switches, or slide plates for easy retrofits.
These assemblies vary by kW output, voltage, manifold length/diameter, sensor type (e.g., Balboa M7 dual thermistor), union style (split nuts/tailpieces), and spa-specific features—exact matching to your control system and plumbing is crucial for proper fit, flow detection, and heater safety. Universal models offer broad compatibility for many older or discontinued packs.
Common issues include no heat from failed elements/sensors, overheating/shutdowns due to scale buildup or bad hi-limits, flow errors (e.g., FL codes) from poor circulation or faulty pressure switches, leaks at unions/gaskets, or corrosion in aggressive water chemistry. Replacing the full flow thru heater assembly often resolves multiple problems at once, restoring fast, reliable heating without piecemeal fixes.
To ensure the right assembly:
- Identify your spa brand, model, year, control pack (e.g., Balboa VS, Gecko Y-series), voltage, current kW, plumbing size, and sensor setup.
- Note any error codes (e.g., OH, HL, FLO) or heater dimensions.
- Avoid guessing—send us clear photos of your existing heater assembly, sensors, plumbing unions, manifold labels, control box, and spa label (model/serial number) for precise verification.
Text photos to 772-800-5445 or call 844-500-4645—we'll confirm compatibility before you order. SpaShopper is not affiliated with any spa manufacturer. Brand names and part numbers are used for compatibility and identification purposes only.
Shop our flow thru heater assemblies today to get your hot tub back to perfect temperature quickly and enjoy consistent, worry-free warmth.