Coates ST Series Electric Heater (Model: 12406ST)
Product Overview
We stock the Coates ST Series 5.5kW Electric Heater, a compact yet powerful heating solution designed specifically for spas up to 400 gallons. This professional-grade unit offers efficient heating in a space-saving design.
Key Features
- Digital thermostat control
- Incoloy heating elements
- Built-in flow switch protection
- Heavy-duty contactors
- Element operation indicator
Design Innovation
- Compact form factor
- Optimized water flow pattern
- Stainless steel tank construction
- Space-saving configuration
- Under-skirt installation capability
Technical Specifications
| Specification | Detail |
|---|---|
| Model Number | 12406ST |
| Power Output | 5.5kW |
| Voltage | 240V |
| Phase | Single |
| Flow Range | 15-80 GPM |
| Dimensions | 17-1/2″L x 4″W x 14″H |
| Connection Size | 1-1/2″ x 2″ |
| Connection Type | Union |
| Tank Material | Stainless Steel |
| Element Type | Incoloy |
| Max Spa Size | 400 Gallons |
Safety Systems
- Manual reset high temp limit
- Integrated flow switch
- Operation indicator light
- Contactor protection
- Temperature monitoring
Installation Features
- Universal union connections
- Compact dimensions
- Flexible positioning
- Under-skirt compatible
- PVC pipe compatibility
Performance Benefits
- Efficient heat transfer
- Wide flow rate tolerance
- Digital temperature control
- Quick heating response
- Energy-efficient operation
Construction Quality
- Premium Incoloy elements
- Stainless steel construction
- Professional-grade components
- Durable contactors
- Weather-resistant design
Usage Limitations
- Not recommended for salt chlorination systems
- Maximum spa capacity: 400 gallons
- Minimum flow rate: 15 GPM
- Maximum flow rate: 80 GPM
Note: Professional installation recommended to ensure proper system integration and safety compliance. Not compatible with salt chlorination systems
🔧 Parts and fittings for this
| Part | Our part number | Availability | Price | ||
|---|---|---|---|---|---|
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Silicone, DOW 732, 3oz Tube, Clear | DC-732-CLR-3 | 186 in stock | $17.88 | Add to cart |
Commonly replaced parts
Parts commonly replaced on this item that we stock.
| Part | Our part number | Availability | Price | ||
|---|---|---|---|---|---|
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Screwplug Element, Coates, Threaded, 5.5kw, 240v, w/ Gaskets | 20005061 | 6 in stock | $83.94 | Add to cart |
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Tailpiece, Coates, w/Split Nut, Heater, OEM | 32705010 | 23 in stock | $23.24 | Add to cart |
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Hi-Limit, 5/16" dia, 12"Cap, SPST, Screw Terminal, Coates 61L/E-6 | 22003820 | 3 in stock | $110.60 | Add to cart |
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Thermostat, Coates PH/CPH/CE/SHB/ST | 22002001 | 5 in stock | $79.00 | Add to cart |
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Contactor, Coates, DP, 35A, 240v | 21000650 | Available to order | $76.04 | |
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Coates Heater Thermostat #22002150 | 22002150 | 6 in stock | $181.68 | Add to cart |




















