A Simple Step-by-Step Guide to Installing a Yonos PICO-Z Pump

This simple guide aims to provide installers with helpful tips for fitting the Wilo Yonos PICO-Z hot water circulation pump as a swap out for an existing bronze pump. We’ll cover everything from unboxing, right through to setting up the pump post-installation.

Before getting into it though, let’s first explain why you need a Yonos PICO-Z. Quite simply, it is one of the most efficient stainless steel hot water pumps on the market, and it is a perfect replacement for bronze pumps which are now becoming antiquated with their technology.

You might be asking, why? Well, while bronze pumps have done the job for years for hot water recirculating systems, they tend to offer only three fixed speeds for operation, drawing up to 100 watts and making them highly energy inefficient. Modern stainless steel alternatives like the Yonos PICO-Z offer better energy savings due to their EC motors. We ourselves are advocating for the ‘End of the Bronze Age’, and to show that we mean it, we’re discontinuing the sale of our own SB30 Bronze Pump from August 2025.

OK, now that’s explained, let’s get into it!

Step one – Unboxing

In the UK, Wilo sells pumps in 130mm and 180mm sizes, so be sure to get the right one from your local plumbing and heating merchant.

Before getting started, make sure to check that all contents are included. Within the box, there should be:

• A QR code to access the Wilo-Assistant app – this has a range of information on pump replacements, troubleshooting guidance and details on other Wilo products
• An instruction manual
• A quick-fit Wilo-Connector for the electrical connection to the pump
• Two replacement rubber washers for the pump valves
• The pump itself (!)

Side note: Our pumps are compliant with Regulation 4 of the UK’s Water Supply (Water Quality) Regulations 2016, which ensures products that encounter potable water are safe and suitable for use.

Step two – Remove the bronze pump

Start by switching off the power supply to the existing pump. You can use a voltage stick to check there is no power going to the pump, and to be extra safe, you can turn off the fused spur at the switch.

Using a spanner, the two pump valves on either side of the existing hot water return pump will then need to be isolated, so that water isn’t flowing through the pump itself.

Once done, you undo the top and bottom nuts on the valves, and then remove the bronze pump, but before you do that, make sure to have a bucket or something similar nearby to catch any residual water from the pipework.

After removing the bronze pump, you can disconnect the power supply and wiring to the pump and set the old pump aside. Now, the Wilo Yonos PICO-Z is ready to be fitted.

Step two – Install the new Yonos PICO-Z pump

Before installing the Yonos PICO-Z pump, make sure that the pump head is orientated correctly – otherwise it will not work effectively.

Doing this is quite easy, as the pump has an adjustable pump head. Quite simply, undo the four bolts in the corners on the face of the pump, spin the direction of the head around to suit the orientation of the pipework, and screw the bolts back in.

Then, position the pump in place between the valves on the hot water system, making sure to also install the new rubber washers supplied at the same time. Use a spanner to lock the pump back into place and ensure a watertight connection.

Finally, lag the pump so that it is properly insulated. Conveniently, the Yonos PICO-Z comes with a thermal insulation shell so that you don’t need to manually cut out lagging for the pump.

The pump also comes with a handy LED display, a dial and buttons to help with commissioning, ongoing monitoring, and maintenance. Therefore, make sure that when installing, the front of the pump is accessible.

Step three – Wiring the pump

The wiring of the Yonos PICO-Z is more straightforward than you might think. Instead of having to fiddle around with each wire separately like most other pumps, we have our unique Wilo-Connector plug for a hassle-free connection.

First of all, if the existing cables are too long, then cut them down so that they are a suitable length. Then, strip the earth, neutral and live wires so that they are exposed, and once that’s done, they can be easily inserted into the Wilo-Connector. Simply pop the cables into the connector and use the tabs to lock them into place, and you’re then ready to push the connector into to the Yonos PICO-Z.

Step four – Commissioning the pump

Once the power cable is connected and the power is turned back on, the pump will fire up.

Here, installers can either use three preprogrammed speed settings, or fine tune the pump’s speed (flow rate) and pressure (head) to suit the building’s needs. All the settings can be accessed from the pump’s green button, which dials left and right.

The Yonos PICO-Z provides users with 42 incremental flow rate settings and 42 incremental pressure settings to optimise the system and make it more energy efficient. Use the left-hand side of the dial to adjust the pump speed, and the right hand side to adjust the pump’s pressure.

As a general rule of thumb, lower speeds will suit smaller commercial properties or homes and means the pump can work from as low as four watts. Meanwhile, the highest speed, is more suited for larger hot water systems and buildings.

Step five – Vent and unblock the pump (optional)

Two other features of the pump that installers might find handy are the venting and de-blocking functions. With the new pump now in place, venting will occur automatically. However, if you need to manually activate this function during future service visits, simply press the white circular button and the pump will vent itself for 10 minutes.

The new model also allows for users to unblock the pump should there be a blockage in the pump. To do this, press the same white button twice.

Both of these functions, and the error codes which feature on the pump’s LED display make it easy to identify and remove airlocks or blockages and ensure the pump is working at its best.

For more information about the Wilo Yonos PICO-Z, visit Wilo-Yonos PICO-Z.