Solar Water Heater Maintenance: Limescale, Heating Element, Anode and Leaks
In Cyprus most homes get their hot water from rooftop solar panels and a storage tank. The system looks simple, but hard water and sun reduce its performance over time. Regular maintenance protects both your hot water and the life of the tank.
Why does the hot water run short?
- Limescale: hard water leaves scale in the tank and panels, making it harder to heat the water
- Dirty panel glass: dust and sand reduce the sunlight reaching the panels
- A faulty heating element or thermostat: the electric heater that works on cloudy days may have failed
- A leak in the tank or pipes
If the heating element trips the RCD
An RCD that trips when the heating element is switched on is a common problem; usually the element is scaled up or has failed. Do not keep switching it back on; a technician checks the element and wiring and replaces it if needed.
What does the magnesium anode do?
The magnesium anode inside the tank corrodes on purpose to protect the tank from rust. Once it is used up, the protection ends and the tank starts rusting from the inside — rusty or brown hot water can be a sign. Checking and replacing the anode at intervals extends the tank’s life.
What does a service include?
- Cleaning the panel glass and checking the connections
- Draining and descaling the tank
- Checking the heating element, thermostat and magnesium anode
- Checking valves, fittings and pipes for leaks; renewing insulation on outdoor pipes
Where the water is hard, a yearly check is a good habit.
What affects the price?
- Number of panels and tank size
- How hard the roof is to access
- Whether the element, thermostat or anode need replacing besides descaling
- Where any leak is and which part has to be replaced
Frequently asked questions
How often should a solar water heater be serviced?
In homes with hard water a yearly check is recommended. If hot water drops or comes out discoloured, have it checked without waiting.
Why is the hot water rusty?
Usually the magnesium anode is used up and the tank has started to rust inside. The anode needs replacing and the tank checking.
Solar is not enough in winter — is that normal?
On short, cloudy days the sun may not be enough, which is why the system has an electric heating element. If the element does not work or trips the breaker, have it checked.