How often does a solar water heater need servicing?

The short answer

The manufacturers who publish a service interval for their solar water heaters — Elco and Solar Star, among the brands checked so far — both specify the same one: every 2 years. That is when the magnesium anode inside the tank is due to be inspected and, almost always, replaced. If you don't know when your unit was last checked, treat two years since installation (or since the last service) as the point to book one. Always defer to your own model's manual where it states a different interval — not every brand publishes one.

What a service actually covers

On the two brands with a documented service scope, the same short list recurs:

• Magnesium (sacrificial) anode — inspected, and replaced if consumed
• The gasket or flange sealing the anode into the tank
• The safety/pressure-relief valve — checked on every visit, replaced on a longer cycle
• The solar thermal fluid in the collector loop — topped up at each service, fully

replaced on a longer cycle

The anode is the item that actually drives the two-year cadence. The rest gets checked at the same visit because the technician is already there, not because each part independently needs attention that often.

Why the anode is the part that matters

A magnesium anode exists to corrode instead of the tank. It is a sacrificial piece of metal that gives up its electrons to the surrounding water so the steel tank around it doesn't. Once it's consumed, that protection stops — and the tank itself starts corroding instead. An anode that looks intact from the outside can already be spent internally, which is why this is an inspection you book on a schedule rather than one you wait to need.

A tank replaced early because nobody checked the anode costs far more than the anode check itself would have.

Parts on a longer cycle

Not everything on the list runs on the same clock as the anode:

1. Safety valve — Elco's documentation puts this on a 4-year replacement cycle, longer than

the anode check

1. Solar thermal fluid — topped up at every 2-year service, fully replaced roughly every

4 years

Both of these are still worth tracking on their own dates rather than folding them silently into "the service" — a technician working from a checklist is less likely to skip a part that has its own due date than one that's implied by "while you're in there."

Before you rely on this

The 2-year figure above reflects the two manufacturers in Epimeleia's catalogue that publish a service interval for their solar water heaters — it is not a universal Greek or EU requirement, and other brands may specify something different or nothing at all. Check your own unit's installation manual or ask your installer for the interval that applies to your model.

Track it in Epimeleia

Add your solar water heater as an item under the property, set its service interval to 24 months (or whatever your manual specifies), and attach the anode-check record each time. The next reminder arrives on schedule, and the history of what was checked is already on the item — no need to remember which year you're due.