The pressure in the solar circuit of DualSun Spring installations will tend to drop during its first days/weeks of operation, until it stabilizes. This phenomenon of pressure loss is normal, and it is due to the relaxation of the polypropylene heat exchangers. These work mechanically under the effect of internal pressure, and over time this pressure slowly decreases until it stabilizes at the head of the installation.
Overall the pressure of DualSun installations will stabilize around the value corresponding to the head of the installation (approximately Hinstallation/10). Sometimes the manometer pressure will read 0, but it is indeed supposed to be Hinstallation/10.
NB: With a measuring range between 0 and 10 bar, the sensitivity of the solar station manometer is sometimes insufficient to observe this pressure.
If a leak on your DualSun installation is suspected, the first step is to check if the system is running properly. For this it is recommended to turn the pump to 100% on the control unit. Then check that the flowrate indicated by the flowmeter is sufficient (1 L/min/panel). As long as the flow is operational, even if the pressure appears low, the installation can function normally.
If there is no flow or it is significantly lower than the nominal flow rate at the time of commissioning, then you will have to ensure there are no micro-leaks along the hydraulic circuit (look for white traces or drops of glycol).
Then, before refilling the installation, make sure that the expansion vessel is inflated. It must be set to P = 0.5 + Hinstallation/10.
Below is a flow chart with the actions recommended by DualSun to verify the correct operation of a Spring installation: