SpaNET SV2, SV3, SV4 V2 Heaters - Variable Output Heater Assemblies
SpaNET SV2, SV3, SV4 V2 Heaters - Variable Output Heater Assemblies - is backordered and will ship as soon as it is back in stock.
Delivery and Shipping
Delivery and Shipping
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SpaNET SV Heater Assembly
- Complete assembly: optical sensor, heater element, temperature sensors, wiring loom
- V2 heaters only are currently available — V1 heaters are discontinued and will require an upgraded control box. Important: V2 heaters cannot be used in V1 SpaNET Control Boxes
- Compatible with SV2, SV3, SV4 V2 control systems (see model table below)
- Standalone heater elements are not sold separately
Important: Heaters may no longer include unions (images may show unions for reference only)
Which version do I need? (V1 vs V2)
- Find the serial number on the front of your controller
- If the serial number ends with “V2” → order the V2 heater
- If the serial number has no “V” number → it is a V1 controller.
Note: V1 heaters are discontinued. If you have a V1 5–6 kW heater, you must upgrade to a new control box (SV2, SV3, or SV4)
Visual check: You can also tell by looking at the heater itself. If it has two Triacs (small components covered by white silicone) it is a V2. If it has one Triac covered by white silicone, it is a V1.
Compatibility at a Glance
| Heater Version | Power Rating | Fits Controllers | Status |
|---|---|---|---|
| SV (V2) | 3.0 kW | SV2 | Available |
| SV (V2) | 5.25 / 5.5 / 6 kW | SV2, SV3, SV4 | Available |
| SV (V1) | 3.0 kW | Usually found in SV2 controllers | No longer available — replace control box |
| SV (V1) | 6.0 kW | SV2, SV3, SV4 | No longer available — replace control box |
What's in the Box
- Heater assembly with integrated heater element
- Optical sensor
- Temperature sensors
- Wiring loom
- Unions are not included
Notes & Installation
- Check your controller serial number before ordering
- V1 5–6 kW setups require a control box upgrade (SV2, SV3, SV4)
- Standalone heating elements are not sold separately
Need help?
Email us with your controller’s serial number and a photo of the data label so we can confirm compatibility.
Contact us
In plumbing, named sizes are not the actual measurements. A pipe called “50mm” or “2"” does not measure 50 mm across. Instead, it follows nominal sizing, an internationally-standardised naming system.
Use the Outside Diameter (OD) to check your pipe against fittings. Below is a quick reference for common spa & pool pipe sizes:
| Imperial Name | Metric Name | Pipe Diameter (OD) |
|---|---|---|
| 1" | 25 mm | ~33.4–33.7 mm |
| 1.5" | 40 mm | ~48.1–48.4 mm |
| 2" | 50 mm | ~60.2–60.5 mm |
| 2.5" | 65 mm | ~75.2–75.5 mm |
These are nominal sizes and are designed to fit matching fittings — not to measure exactly what their name suggests.
Understanding Plumbing Sizes & Nominal Measurements
Plumbing sizes can be confusing. PVC and many other pipe systems use nominal sizes—the size is a name, not the exact measured dimension. This convention is used across most pool and spa systems so that pipes and fittings remain compatible.
Why pipe sizes don’t match the measurements
The Nominal Pipe Size (NPS) system standardises pipe dimensions so that pipes, fittings, valves, and accessories interoperate. Plumbers work with these nominal names every day, but DIYers can be tripped up if they try to match by a tape-measure alone.
How to Measure Pipe Correctly
-
Pipe size is identified by:
- The pipe’s Outside Diameter (OD).
- The fitting’s Inside Diameter (ID) (socket opening).
- Pipe Class / Schedule (e.g., Class 9, 12, 18 or Sch 40) relates to wall thickness and therefore the Internal Diameter (ID) and pressure rating.
- The outside diameter of a fitting is not useful (wall thickness varies by manufacturer).
PVC Pressure Pipe AS/NZ 1477 Dimensions1:
Common nominal sizes with typical outside diameters and indicative inside diameters by class.
| Imperial Name | Metric Name | Outside Diameter (OD) | Class 9 IDº | Class 12 IDº | Class 18 IDº |
|---|---|---|---|---|---|
| 1/2" | 15 mm | ~21.2–21.5 mm | 18.3 mm | 17.8 mm | |
| 3/4" | 20 mm | ~26.6–26.9 mm | 23.7 mm | 22.4 mm | |
| 1" | 25 mm | ~33.4–33.7 mm | 30.5 mm | 29.8 mm | 28.1 mm |
| 32 mm | ~42.1–42.4 mm | 38.5 mm | 37.5 mm | 35.4 mm | |
| 1.5" | 40 mm | ~48.1–48.4 mm | 45.2 mm | 44.1 mm | 42.8 mm |
| 2" | 50 mm | ~60.2–60.5 mm | 55.2 mm | 53.7 mm | 50.5 mm |
| 65 mm | ~75.2–75.5 mm | 68.9 mm | 67.0 mm | 63.2 mm | |
| 2.5" | ~73 mm |
- º Internal diameters vary slightly by manufacturer and class.
- 1 Not all pool/spa fittings match these dimensions exactly. Some do not follow Australian or international standards. Chinese spas may use proprietary fittings.
Hose & Tube Dimensions
Common flexible hose sizes used in pool/spa systems (approximate IDs).
| Imperial Name | Metric Name | Inside Diameter (ID) |
|---|---|---|
| 3/8" | 9–10 mm | ~9 mm |
| 3/4" | 19 mm | ~19 mm |
BSP – British Standard Pipe Thread Sizes
BSP thread names are also nominal. The thread OD will not equal the nominal name.
| BSP Thread Size Naming | Outside Diameter (mm / inch) | TPI |
|---|---|---|
| 1/16" BSP | 7.7 mm / 0.304" | 28 |
| 1/8" BSP | 9.7 mm / 0.383" | 28 |
| 1/4" BSP | 13.16 mm / 0.518" | 19 |
| 3/8" BSP | 16.66 mm / 0.656" | 19 |
| 1/2" BSP / 15 mm | 20.99 mm / 0.825" | 14 |
| 5/8" BSP | 22.99 mm / 0.902" | 14 |
| 3/4" BSP / 20 mm | 26.44 mm / 1.041" | 14 |
| 7/8" BSP | 30.20 mm / 1.189" | 14 |
| 1" BSP / 25 mm | 33.25 mm / 1.309" | 11 |
| 1-1/4" BSP | 41.91 mm / 1.650" | 11 |
| 1-1/2" BSP / 40 mm | 47.80 mm / 1.882" | 11 |
| 2" BSP / 50 mm | 59.61 mm / 2.347" | 11 |
| 2-1/4" BSP | 65.71 mm / 2.587" | 11 |
| 2-1/2" BSP | 75.18 mm / 2.960" | 11 |
| 3" BSP | 87.88 mm / 3.460" | 11 |
| 4" BSP | 113.03 mm / 4.450" | 11 |
| 5" BSP | 138.43 mm / 5.450" | 11 |
| 6" BSP | 163.83 mm / 6.450" | 11 |
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