Solar Water Heaters and the Winter Season
1. In the winter season, we permit the use of the system only together with protection in the form of a control system and an electric heating element.
Based on our conducted research, even during -20°C frosts, the water in the tank should not freeze if the collector is regularly cleared of snow. On sunny winter days, water temperatures have been known to exceed 60°C. The excellent insulation of the tank ensures that the water temperature drops quite slowly. Unfortunately, there are days in winter when the amount of sunlight may be insufficient. A short day, the possibility of the solar system being covered with snow, or heavy frost on the vacuum tubes will also limit the amount of heat obtained. If we do not monitor the water temperature, freezing and failure may occur. To prevent this, it is sufficient to install an electronic temperature sensor in the tank. In the event of a dangerous temperature drop, the electric heater is turned on. The entire control and system protection process can be automated by connecting an appropriate controller.
2. We recommend completely draining the system of water for the winter season.
a) In the case of heaters from the PROECO Solaris-P, Hydra-P and HP (pressurized) series:
- Completely drain the installation of water – however, in this case, the vacuum tubes with heat pipes must be dismantled (or covered with a dark, light-impermeable material). Leaving the vacuum tubes heating an empty tank can cause damage to the thermal insulation (melting of the polyurethane foam) and, in the worst-case scenario, even damage to the tank (implosion).
- Relieve the pressure inside the tank and drain the water to below half of its capacity (to about 1/3 of the volume). In the building, shut off the ball valves located on the cold and hot water lines, then open the temperature & pressure relief valve located on the tank. However, the solar collector must be regularly cleared of snow. Leaving the vacuum tubes in place can cause mechanical damage by ice (snow accumulated between the vacuum tubes). The connection pipes (water inlet and outlet) can also be damaged.
b) In the case of heaters from the PROECO Solaris-L, Hydra-L and YL (non-pressurized) series and MK collectors (if filled with water):
- Completely drain the installation of water. In this case, the vacuum tubes must also be dismantled. Leaving water in the vacuum tubes can cause them to break (and will lead to scale build-up inside them). Leaving the vacuum tubes in place can also cause mechanical damage by ice (snow accumulated between the vacuum tubes).
c) In the case of heaters from the PROECO Solaris-X and HX (coil-type, instant-flow) series:
We recommend complete disassembly (of the tank and the vacuum tubes). However, if the tank must remain outside during the winter, you should:
- Unscrew the connection fittings at the coil and then tilt the tank so the fittings point downwards. Wait until all the water drains out of the coil.
- Blow through the entire coil with compressed air (e.g., using a compressor)
Leaving water in the copper coil can cause it to break.
Leaving the vacuum tubes in place can also cause mechanical damage by ice (snow accumulated between the vacuum tubes).
3. Do not drain the tank of water when the anti-freeze protection is installed and active in the form of a control system and an electric heating element. This can lead to burning out the heater or even cause a fire. If the tank has been drained of water even partially, the electric heater inside the tank becomes exposed. The power supply to the electric heater must be permanently disconnected.
4. In the winter season, the pipes supplying water to the device must also be protected against freezing. This is particularly important when pipes are made of hard and brittle materials (copper, cast iron, steel). We recommend using electric heating cables for this purpose. Plastic pipes (e.g., PEX pipes) tolerate water freezing within them much better.
5. All valves, and in particular safety valves, should be located inside heated buildings. The only exception is the temperature & pressure relief valve mounted at the top of the tank on PROECO Solaris-P and HP series heaters.
Any failures resulting from the user's non-compliance with our recommendations (which are also listed in the installation and operating instructions of the devices) may lead to the rejection of the warranty claim.