OVB heat exchanger - 20kW for pool up to 20m3

OVB heat exchanger – professional pool heating without compromise

The OVB heat exchanger is designed for heating swimming pool water and water in hot tubs. It is most commonly used for pool heating with:

• gas boilers
• heat pumps
• solar collectors

Thanks to stainless steel AISI 316, it offers high corrosion resistance and long service life even in demanding pool environments.

How the heat exchanger works

Inside the exchanger body there is a bundle of small tubes through which heating water flows (primary circuit). Pool water (secondary circuit) flows around these tubes. Heat is transferred through the tube walls, allowing the pool to heat up quickly. Once the pool reaches the set temperature, the system switches off (controlled by a thermostat or automation).

Why water quality is crucial

The service life of the heat exchanger and the entire pool system is primarily influenced by water quality. Regular pH control, correct chlorine dosing, and properly functioning filtration significantly extend the lifespan of the equipment and increase bathing hygiene safety.

Operating conditions and recommendations (pool installer practice)

• Regularly check the water pH (ideally daily) and keep it within the recommended range.
• If you use a by-pass, adjust the valves to ensure the recommended flow rate through the exchanger – incorrect flow can cause corrosion or erosion.
• Keep the pool free of solid debris (leaves, grass, etc.), which degrade water quality and may increase pH.

Commissioning

Before start-up, check:

• Pressurized connections are tight and leak-free.
• The exchanger is properly mounted and connected according to the installation diagram.
• The heating circuit is filled and properly vented.
• Grounding is completed and residual current protection (30 mA RCD) is functional.

Start-up procedure:

1. Start the filtration pump.
2. Check circulation of pool water through the heat exchanger.
3. Check filling and venting of the heating circuit.
4. Switch on the residual current device (30 mA).
5. Set the desired temperature on the thermostat (or automation unit).
6. Verify correct operation of the control automation for heating and filtration.

Conditions that must switch off heating

• Lowering the set temperature on the thermostat.
• Switching off filtration or closing a valve (loss of flow).
• Switching off the heating button / heat demand.

For safe operation, a thermostat and a flow switch are required. If there is no flow, the flow switch shuts down heating to prevent overheating and deformation of piping. The thermostat prevents overheating of the pool above the desired temperature.

Important safety notice

Before performing any work on the circuit or electrical components, make sure the unit is disconnected from the power supply and the circuit is closed.

Connecting the OVB heat exchanger to the filtration and heating circuits

Secondary circuit (pool water): 1 1/2" female thread. It is recommended to use a brass fitting with a PVC tail, into which a 50 mm pipe is subsequently glued. Do not use PVC fittings directly on the exchanger thread – due to high temperatures, the thread may loosen and cause water leakage.

Primary circuit (heating water): 3/4" female thread.

Use the supplied mounting brackets to fix the exchanger to the wall.

Package contents

• Heat exchanger body
• 2× wall mounting brackets
• 2× clamps

We recommend purchasing these additional products for installation

Technical data – OVB 70 (20 kW)

Pool installer tip: most common installation mistakes

• Too low or too high flow rate through the exchanger – always adjust the by-pass to the recommended flow.
• PVC fitting directly on the exchanger thread – may loosen at higher temperatures. Use a brass fitting.
• Incorrect chemical dosing (high concentration in one spot) – may damage metal parts and seals.
• Neglected filtration – sand and debris can severely damage the exchanger and piping.

Who is the OVB heat exchanger best suited for

We recommend the OVB heat exchanger wherever stable performance, high durability, and long-term reliability are required. It is suitable for chlorinated pools with sand filtration, whether for an outdoor family pool or an indoor pool installation.