EcoOnline Vertex™ Solar Spa Heating Systems

Is your spa (or pool) heating system costing you a small $$$ fortune $$$ to run? The good news is that there is now a much smarter way to offset heating costs! Using our super efficient OKU HDPE collector, innovative Vertex™ solar spa heating system you can easily offset the majority of your heating costs, and it runs on a small PV solar panel, so it runs 100% FREE, that's right - ZERO running costs. Finally, there is such a thing as a free lunch :)

The Vertex™ system come with premium German made collector panels designed and adapted for Australian conditions that come with an extraordinary industry first 35 Year Warranty. They are made from ultra-durable (UV stabilized) potable grade HDPE - an outstanding material with proven longevity and a very long industry pedigree in the harsh Australian sun. They are made extremely tough and are resistant against all that nature can throw at them.

If you already have an existing gas or electric heater, you can still benefit from our system by offsetting utility bills and extending the life of your heater (by reducing its on time).

Solar Spa Heater Panels

celebrating 8 years of Vertex™ Systems

We're celebrating 8 years of Vertex™ heating system innovations and refinements:

  • Flood-Prime Version 1: First systems introduced to market in Jan 2011.
  • Flood-Prime Version 2: Added panel mounted under-temperature thermostat to prevent spa cooling during cold but sunny spring days.  Added stronger pumps and a new reconfigured position for the vacuum release which improved flow rates.
  • Flood Prime Version 3: Removed the need for any 12V electrical work with snap lock electrical connectors and versatile extension cord. Also added non-return valve and by-pass line.
  • Flood Prime Version 4 (Present Version):Introduced an innovative new plumbing arrangement with a self-clearing air bubble pump pre-filter and a post pump air bubble removal chamber making the system almost completely impervious to pump burnout from air-locks & blocked flow.
  • self-prime Version 1 (Present Version): First systems introduced to market in Jan 2016. Builds on all other Flood-Prime versions - adds a large fine filter canister with a new plumbing arrangement to achieve self-priming to the list of features, which means the pump and assembly can be mounted anywhere above the water level and a flexible drop line can be used as a suction line. Eliminates spa perforations and the need to mount pumps below the water level. Heat your pool or spa by flopping the suction and return lines between the two. No spa modifications means it's more portable, take it with you if you move house.

Vertex™ Spa Heater System Feature

ZERO electricity usage - help combat climate change by reducing your emissions
Uses only small pumps, which means the system is whisper quiet
Safe extra low voltage, low amps ~ 18VDC, 2.8Amps Max
German quality HDPE polymer collectors should last +35 years
Cockatoo and Hail proof, made from solid HDPE
Clean potable grade HDPE polymer & silicon joiners, no rubber or plasticized PVCs
Performance when you need it most- in Cooler Weather Conditions
No mains pump, the
system is fully powered
by a small solar PV
Fully automated & self-regulating, sunlight turns the system on/off
Simple 12V system means reliability and easy DIY

Ideal Suggested Applications

Ideal applications include:

  • Heating for a small spa or spa pool
  • Off-set utility bills for larger gas or electric heated spa or spa pools
  • or heating smaller above ground pools
The Vertex™ Solar system is sold as an easy to setup DIY12V kit. It's separate from your filter system and requires no mains 240V power connections. Includes a comprehensive step by step installation manual and can be put together in a few hours as a fun project.

How much can I save on heating costs?

This depends on what you're using to heat your pool, swim spa or spa pool and where you are located. The table below gives the heat energy collected per (1.2m²) collector gross area across an entire swimming season and the equivalent cost of this heat energy obtained using either gas, electric heat element or heat pump units.

Average Daily Insolation/m²
Energy Collected
Gas (1kWh=3.6 MJ)
Electric Element Offset
Heat Pump Offset
Melbourne (Oct-Mar)
6.7 kWh
733 kWh
Sydney (Oct-Apr)
6.5 kWh
696 kWh
Brisbane (Oct-Apr)
6.7 kWh
716 kWh


  • We assume the Vertex system is optimally mounted and undersized so that each collector is maximally utilized.
  • We count only the energy collected across the swimming season specified.
  • The Average Daily Insolations (or peak sun hours) across the swimming seasons are assumed to be 6.08kWh/m² (Melbourne), 5.94kWh/m² (Sydney) and 5.91kWh/m² (Brisbane) (source:
  • We assume an average gas price of 2.75c/MJ and electricity price of 22.5c/kWh (source:
  • We assume an overall unglazed collector conversion efficiency of 60%, gas boiler efficiency of 80%, and heat pump efficiency of 300%.

To obtain the anticipated energy savings simply multiply the size of your system by the relevant energy cost - hence for a 4 panel spa heating system in Sydney, off-setting an electric heat element the anticipated annual savings are $157 x 4 = $628.

Sizing Your Vertex™ Solar Spa or Pool Heater

For vinyl foam covered spa pool or swim spa please use our covered spa interactive sizing calculator to accurately size your system. For uncovered or solar blanket covered swim spa or small pools please use our uncovered spa interactive sizing calculator to accurately size your system. If you have any difficulty please contact us.

Roof Mounting Your Vertex™ Solar Pool Panels

In terms of roof mounting, panels are simply strapped down around their 40mm header pipes to aluminium channels top and bottom using the 6 supplied 316 stainless metal straps. The aluminium channels need to be fixed down by screwing through into battens or rafters. Tile installations are more involved using solar roof hooks that are screwed into rafters and have a protruding external under tile arm/hook that holds the aluminium channels top and bottom on the roof. Dual header panels join end to end horizontally across the roof in a single row (or two or three rows). It's even possible to mount panels on their sides; such that the short side runs up the roof. See manual for full description.

OKU performance Dimension Specifications
Dual Header OKU Panel
Gross Area (as mounted)
Aperture Area (black area)
Panel Edge to edge length
As mounted Edge to edge Length
Panel Pipe to pipe width
Absorber edge to edge width
Dual Header Pipe OD
40mm metric
Interconnect Pipe OD
25mm metric
flow rate range
Water content
Panel Weight
6 kg (or 12kg with water)
Recommended working pressure
-1 to 1psi
Frost resistant
-20 to + 115°C

Wind Loading Considerations

In terms of wind loadings on panels our roof fixing methodology is the highest in it's class up to wind region C. See manual for full description. We like to take a cautious over-engineered approach to wind loadings and suggest installers do the same as it's very easy to put down more fixings. However, there are some cases where we can't recommend panels over tubes due to high wind loadings (if in doubt please as ask). As a guide please note the following recommendations:

Wind Region
Single Story Metal Roof
Single Story Tile Roof
Double Story Metal
Double Story Tile
Wind Region A
Wind Region B
Sheltered Location Only
Not Recommend
Wind Region C
Sheltered Location Only
Not Recommend
Not Recommend
Not Recommend
Wind Region D
Not Recommend
Not Recommend
Not Recommend
Not Recommend

Spa Plumbing Considerations

You need to consider the type of system you need, self-prime or flood prime, the above mentioned sizing calculators for covered spas and uncovered spas will advice you on the type of system you'll need. We show both types of available Vertex systems below:

Vertex Flood-Prime Plumbing
Vertex self-prime Plumbing

Basically, the Flood-Prime system has strict plumbing rules, pumps must be mounted well below the waterline of the spa with appropriate slope plumbing that contains no air locks, a while the self-prime system can be mounted above the water line or with lines over the top and will always self-prime.

Available Extras (upon request)

Extra parts

1 x Extra OKU dual header panel kit

Includes joiner, clamps and strap set

oku dual header extra panel

304 Stainless Solar Roof Hooks for Tiles (height adjustable)

Dimensions: A = 47.5mm, B = 112mm, C = 60mm

Available on request for $8.50 each.

Please note: if you have tiles need solar roof hooks please contact us as we need to work out how many you'll need to use.

Solar roof hook

Shipping Cost & ETA Estimate

For a shipping estimate, please add this listing to your cart and click on the cart icon at the top right of this page, then click "Estimate Shipping" on the cart page. The shipping estimated time of arrival (ETA) can be checked on our shipping calculator here. We ship from Melbourne Victoria.

Safety Requirements and Product Limitation Considerations

    The following outlines mandatory suitability and safety requirements for installing a Vertex™ Solar heating system. Please read carefully and consider all points, if any of the following requirements cannot be met, a Vertex™ Solar system should NOT be purchased or installed.
    1. The Vertex system is to be used for chlorinated or otherwise treated outdoor spas and pools only.
    2. Under no circumstances should collectors be installed so as to compromise the effectiveness of a child pool or spa fence safety barrier by providing a climbable object.
    3. Due to the potential of falling from heights, mounting the solar panels on a roof or structure at heights should only be undertaken by a professional solar panel installer, unless you are accustomed to and confident of performing the work.
    4. Due to the remote possibility of a water drain down event caused by the Vertex system, this system should not be installed on a pool or spa pool with a mains power electrical devise that does not have a working over temperature protection device and/or will not fail safely in the event of dry running.
    5. At present this collector array system is not recommended for installations in cyclonic regions C or D, or on houses situated on top of hills exposed to strong winds, or on second story (or higher) roofs.
    6. The Vertex System is not self-priming and requires the installation of the pump outside of but below the water line of your pool/spa.
    7. We recommend collectors be installed with a minimum 5Deg roof pitch to ensure reliable evacuation of air bubbles.

      Frequently Asked Questions (FAQs)

      Q. How large are the panels?
      A. You should budget a gross panel dimension of approx 140cm in length and 85cm in pipe to pipe width or about 1.2m² per panel.

      Q. How many panels do I need?
      A. For vinyl foam covered spa pool or swim spa please use our covered spa interactive sizing calculator to accurately size your system. For uncovered or solar blanket covered swim spa or small pools please use our uncovered spa interactive sizing calculator to accurately size your system. If you have any difficulty please contact us.

      Q. Can I power this system using my own solar panel?
      A. Yes - but only if it the recommended wattage, i.e. 40W or 60W. The specific power of the solar panel is an integral design aspect of the control system. Over-powering the pump will result in the system running in cloudy conditions which would cool your spa water and be counterproductive.

      Q. What can I expect from the system throughout the year and in winter?
      A. Typically the system is sized to supply enough energy to bring the spa up to working temperature for about half the year in Southern states and three quarters of the year for mid latitude Australian states. In winter in Southern Australian states the system will struggle to come ON. Outside air temperatures need to be at least 16-18C with full sun before an unglazed panel system has any chance at harvesting energy at typical spa bath temperatures 35-38C.

      Q. Is this system stand alone?
      A. Normally no - in winter in Southern Australian states the system may not even turn ON. On demand auxiliary back up heating is required if you want on demand spa usage. On the other hand if you want to use your spa opportunistically when it is up to temperature, then the system can be considered stand alone in that respect.

      Q. I don't have independent solar lines installed on my pool can I tee into my main filter pump suction line?
      Generally we don't recommend this as you may have priming issues with your main filter pump during start up due to air been drawn in from the solar line tee you installed. Whether your filter pump will deprime in this case will depend on how far below the waterline you installed the solar tee.

      Q. Do we have installers?
      At present unfortunately no we do not have installers as we ship around Australia. However, our manuals are very comprehensive and cover most situations and issues. There is also unlimited tech support available. Most handymen/tradespeople can install our systems. From what we hear, solar pool heating installs are very seasonal, hence most specialist pool heating installers are run off their feet during the install season, this means they charge an arm and a leg for poor rushed installs. Our advice is if you can DIY safely or source a trusted installer that will take his/her time, you will save a great deal of money and headaches.

      Q. Can I download your comprehensive manual before I purchase?
      A. Yes, in fact we highly recommend you check over the manual to get a good idea of installation requirements before you purchase. The manual can freely be downloaded from our EcoOnline download page.

      Q. Is this system easy to install for tiles?
      A. Installation on tiles is more difficult and we recommend should only be attempted by experienced DIY or tradespersons.

      Q. Can I slow the flow to increase the temperature gain?
      A. No, this is a common misconception. Slowing the water flow will result in a warmer outlet but also less harvested energy overall since there is much less warm water flowing. This is because the panel is being made to work at a higher temperature and hence a lower efficiency. Faster flow rates better strip the heat from the panels (up to a point of diminishing benefit).

      Q. Can I use glazed panels with this system?
      A. Strictly No - For a number of safety reasons we strongly recommend you not use glazed panels with our system, nor should you install glazing over the panels. Glazed panels have a much higher stagnation temperature and can boil and potentially sputter boiling hot water, or otherwise send scolding high temperature water through the system. The Vertex system is designed with safety in mind first and foremost.

      Q. The 40DegC over-temperature thermostat is too high is it adjustable?
      A. The over-temperature thermostat is attached to the return pipe -hence the average spa water temperature should not reach 40DegC. It could however reach 38DegC depending on the number of panels installed and the flow rate. If a lower temperature is required we recommend a PVC ball valve is used to restrict flow and increase the temperature differential across the panels, this will drop the average spa water temperature down during thermostat cut-off. This indirect form of temperature control is preferred as it is gentler on the system.

      Q. Can I tap into my spa bath lines?
      A. No, we don't recommend this due to the potential for unforeseen interference with spa bath systems. The Vertex system should be installed as an independent system with dedicated outlets/inlet into the spa.

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