How to guide

How to pre-charge pressure in the integrated pressure tank of the SCALA2

Watch the video and learn how to pre-charge pressure in the integrated pressure tank of the SCALA2.

Checking the pre-charge pressure

Grundfos recommends adjusting the pre-charge pressure in the integrated pressure tank of the SCALA2 during installation, followed by a yearly check. This is because all pressure systems with air expansion vessels require proper pre-charge pressure for optimal operation. Failure to maintain proper pre-charge pressure can lead to issues such as noisy operation, fluctuating pressure, increased risk of damage, and higher energy consumption.

Step 1: Stop and depressurise the system

Stop the SCALA2 by pressing the STOP button. To depressurise the system, close the supply pipe and either open a tap to release any remaining pressure in the system or disconnect the pump from the pipes.

Step 2: Adjust the air pressure

Unscrew the air valve cap on the pressure tank. Pump in air until the required pressure is reached, which should be 70% of the setpoint value/desired discharge pressure (see table below for optimal tank pre-charge pressure settings). Remount and securely tighten the air valve cap.

Step 3: Reopen the supply valve and restart SCALA2

Open the supply cut-off valve and turn the SCALA2 back on.

Optimal tank pre-charge pressure setting – Bar(Psi)

Grundfos advises ensuring optimal pre-charge pressure at the pump installation, setting the pressure to be at 70% of the setpoint value/desired discharge pressure and never above it. The SCALA2 is delivered with a default pre-charge pressure of 1.8 Bar/26 Psi, due to transport regulations, and a default setpoint of 3 Bar/44 Psi, which is the optimal discharge pressure for most households. The correct pre-charge pressure should be adjusted according to the setpoint value when installed.

Learn how to install SCALA2