Madimack MJ Box Pump Controller - Heat Demand Controller
Madimack MJ Box Pump Controller - Heat Demand Controller is temporarily out of stock and will ship as soon as it's available.
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Delivery and Shipping Info
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Warranty Information
Warranty Information
Madimack MJ Box Pump Controller - Heat Demand Controller is temporarily out of stock and will ship as soon as it's available.
Madimack MJ Box Single Pump Controller, Heat Demand Control
The MJ Box lets your pool heat pump call for the filtration pump on demand, overriding a chlorinator, dosing system or timer. You use the same filtration pump for heating instead of running a second pump, which saves energy and simplifies the equipment area. Part code MM-MJBOX-400.
- RRP $553.81 is the manufacturer's recommended retail price.
- Warranty: Madimack's published schedule for the MJ Box single pump controller is 2 years.
- Australian Consumer Law guarantees apply to every purchase, on top of any manufacturer warranty.
- FREE SHIPPING on all Madimack products over $149.00
- Physically Stocked, unlike most "drop-shipping" websites.
- Shipped from VIC, NSW, WA, QLD
Documentation: Specification Sheets & Updated Manuals | Up-to-Date Madimack Recommended Retail Prices
This allows pump control override of a chlorinator, dosing system or timer, using the same filtration pump for heating. Save energy by not having to run another pump to initiate the pool heat pump. Basically, you just set the temperature on the heat pump, and it will automatically run the circulation pump while it's heating, bypassing any other timers set up. Simple!
How do you install it?
Hard-wire the single pump controller to your heat pump, plug it in, and there you have it. We provide a wiring diagram with every single pump controller.
How does it work?
- The onboard output relay initiates the filtration pump through the single pump controller regardless of the chlorinator timers.
- The output relay is initiated as soon as the heat pump is turned on, and the output keeps running until the desired heating temperature is reached, or until the heat pump is turned off by the Wi-Fi timers or manually from the round controller.
- If the unit reaches temperature while still within the timer set points, it tests the water by starting the filtration pump once an hour for 2 minutes to get an accurate temperature reading, then starts the heating process again if required.
- When Wi-Fi timers are set through the app, the relay switch runs the pump output accordingly.
- Timers for the heat pump are on the Wi-Fi app. If no Wi-Fi is available an additional timer may be required, and internal settings need changing to suit this operation.
- The chlorinator runs independently, maintaining the right chemical balance for your pool water.
As with all electrical work, a qualified person such as an electrician should carry out any electrical related work.
MM-MJBOX-400
Warranty
Madimack's published warranty schedule for the MJ Box single pump controller is 2 years. Australian Consumer Law guarantees apply to every purchase, on top of any manufacturer warranty.
Frequently Asked Questions
What does the MJ Box actually do?
It gives your heat pump control of the filtration pump. When the heat pump calls for heat, the MJ Box runs the circulation pump regardless of the chlorinator or timer settings, and stops it once the set temperature is reached.
What does it connect to?
It hard-wires to your pool heat pump and switches a single filtration pump. The chlorinator stays on its own circuit and keeps running independently to maintain water balance.
Do I need an electrician to install it?
Yes. As with all electrical work, a qualified person such as an electrician should carry out any electrical related work. A wiring diagram is supplied with every single pump controller.
Will it still heat if my chlorinator timers are off?
Yes. The onboard output relay initiates the filtration pump regardless of the chlorinator timers, so heating is not limited to your chlorinator's run windows.
Does it need Wi-Fi?
Heat pump timers are set through the Wi-Fi app. If no Wi-Fi is available an additional timer may be required, and internal settings need changing to suit that operation.
What does the warranty cover?
Madimack's published schedule for the MJ Box single pump controller is 2 years. Australian Consumer Law guarantees apply on top of that manufacturer warranty.
To the layperson, plumbing sizes and their names can be confusing due to the nominal sizes and naming conventions used.
This is not something we made up. Plumbers and manufacturers have used nominal (meaning ‘by name only’) sizing for decades.
Simply put, in plumbing, named sizes are often not the actual measurements of the pipe, fitting, or part. A PVC pipe called “50mm” or “2"” does not measure 50 mm anywhere. Instead, it follows nominal sizing, an internationally-standardised naming system.
Almost all fittings we use in the pool & spa industry use “pressure PVC” pipe & fittings. Do not confuse with “DWV” or other pipe & fittings and their names and sizes.
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) |
|---|---|---|
| 1/2" | 15mm | ~21.2–21.5 mm |
| 3/4" | 20mm | ~26.6–26.9 mm |
| 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 |
To reiterate, these are nominal sizes and are designed to fit matching fittings — not to measure what their name suggests. These are based on PVC Pressure Pipe AS/NZ 1477 Dimensions1.
- 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.
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 and other plumbing areas 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).
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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MM-MJBOX400


