A solar water heater has more moving parts than solar panels and therefore requires regular maintenance. This not only extends the lifespan of your system but also ensures you keep enjoying affordable hot water.
For a solar water heater in top condition
The various moving components (pump, valves, sensors, and a closed circuit with fluid) can wear out or become dirty over time. Without maintenance, you risk reduced performance, leaks, and even freezing of the system during severe winters.
6 simple checks you can do yourself
You don’t need to be a technician to carry out a few easy inspections:
- Check the thermal insulation of the outdoor pipes, as birds often pick pieces off to build their nests.
- Does a message or flashing light appear on the control unit? Check whether the probe wire has been damaged by birds.
- Make sure the passage through the roof is still watertight, especially after heavy rain.
- Inspect the connections and valves for any leaks.
- Ensure the sensors are not covered with dead leaves.
- Check the pressure on the pump unit of the solar system. If the gauge shows a value near zero or below the mark, contact your installer. Low pressure means the system is not functioning properly.
What does a technician check?
Although regular self-checks are important, professional maintenance remains essential. An installer will examine:
- the pump, seals, valves, and other wear-prone parts
- the condition, settings, and parameters of the expansion vessel
- the antifreeze fluid, which protects against freezing down to -25°C. Depending on the system type, it usually needs replacing every 4 to 10 years
- the storage tank (checking for scale, corrosion, and anode wear)
Descaling the storage tank: essential for your solar water heater
In Brussels, tap water is quite hard, which means limescale builds up faster in the hot water tank. This slows heating and increases energy consumption.
A technician can clean and descale the tank – usually every 3 to 5 years, depending on your home. Regular descaling can save up to €50 per year on your energy bill and keep your solar water heater in top condition.
Do you live in the Brussels-Capital Region? Check the water hardness in your street
Is maintenance mandatory?
No, maintenance is not legally required as it is for boilers. However, it is strongly recommended: regular inspections prevent breakdowns, significantly extend lifespan, and guarantee optimal performance. Without maintenance, you may also lose warranty rights.
How often is maintenance needed?
For most households, a check every three years is sufficient. However, more frequent maintenance may be wise in cases of high hot water consumption or hard tap water (often the case in Brussels).
Money-saving tip
- Do you have a solar water heater combined with a boiler? Schedule maintenance together with the mandatory boiler inspection to pay for just one visit.
- Using a heat pump alongside your solar water heater? Plan the annual check of the cooling circuit at the same time as the solar heater inspection.