Davey Spa-Quip Spa Power Optical Water Sensor - Error 1, 4, H2O Repair Parts
Davey Spa-Quip Spa Power Optical Water Sensor - Error 1, 4, H2O Repair Parts is backordered and will ship as soon as it is back in stock.
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Don't Guess - Ask Us!
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Delivery and Shipping Info*
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Davey Spa-Quip Spa Power Optical Water Sensor - Error 1, 4, H2O Repair Parts is backordered and will ship as soon as it is back in stock.
Davey SpaQuip Spa Power optical water sensor, commonly associated with water detection faults such as Error 1, Error 4, H2O Error, H20 Error, and in some cases Error 06 on selected Davey SpaQuip Spa Power controllers.
This sensor is used on many Spa Power heater assemblies and can fail with age, cracking, over-tightening, calcium build-up, or poor water chemistry. If the clear sensor body is cracked, cloudy, calcified, or leaking, replacement may be required.
Kept in Physical Stock for Fast Shipping or Local Pick-Up
Important Fitting Notes:
- Finger-tighten only. Tools should not normally be needed. Over-tightening can crack the clear sensor body.
- Check the sensor port and heater tube for calcium build-up before fitting the new sensor.
- Poor water balance can cause sensors to scale up or fail prematurely.
- After fitting, reset the controller by holding the top 4 buttons on the touchpad at the same time until the system reboots. Once rebooted, go to the menu and select Load Defaults.
Suits selected Davey SpaQuip Spa Power controllers including:
- Spa Power 400 / SP400
- Spa Power 600 / SP600
- Spa Power 601 / SP601
- Spa Power 750 / SP750
- Spa Power 800 / SP800
- Spa Power 1000 / SP1000*
- Spa Power 1200 / SP1200
Compatibility Notes:
- SP400: May be fitted to some systems, but replacement is not always recommended without checking the exact heater assembly and fault first.
- SP1000: Some Spa Power 1000 systems used an optical sensor with a finer thread. If your system has the fine-thread version, this sensor will not fit and you may need to upgrade the heater assembly.
- Older SP500 / SP500A: This sensor does not suit older Spa Power 500 or 500A systems. They may use one of these sensors instead.
Common Search Terms:
Davey SpaQuip optical sensor, SpaQuip Spa Power water sensor, Spa Power H2O error sensor, Spa Power H20 error sensor,
Davey Spa Power Error 1 sensor, Error 4 optical sensor, Spa Power 600 optical sensor, Spa Power 800 optical sensor,
Spa Power 1000 optical water sensor, Spa Power 1200 water sensor.
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 | ~60.2–60.8 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) |
|---|---|---|
| 1/2" | 15 mm | ~21.2–21.5 mm |
| 3/4" | 20 mm | ~26.6–26.9 mm |
| 1" | 25 mm | ~33.4–33.7 mm |
| 32 mm | ~42.1–42.4 mm | |
| 1.5" | 40 mm | ~48.1–48.4 mm |
| 2" | 50 mm | ~60.2–60.8 mm |
| 65 mm | ~75.2–75.5 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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