Go through these points
- whether the heater is getting power and the breaker isn't tripped
- whether the thermostat is set to its usual level
- whether hot water runs out faster than before — points to limescale or the heating element
- whether the mixer tap is blending cold water into the hot — then the problem is in the mixer, not the heater
- whether there are signs of moisture under the heater — then it's the tank or a connection
What's repairable and what isn't
The heating element, thermostat, anode and connections are replaceable parts. But if the tank itself is corroded through and leaking, repair isn't sensible and the unit needs to be replaced.
Limescale buildup slows down heating and puts strain on the heating element. During maintenance the deposit is removed and the anode's condition is checked.
How to delay the next fault
Regular maintenance with an anode check is the simplest way to extend the water heater's lifespan. Keeping the temperature very high speeds up limescale formation.
How to tell the heater apart from the mixer tap
A common situation: the heater works, but the tap gives lukewarm water. The cause is usually a thermostatic mixer or a single-lever mixer cartridge that blends cold water into the hot. To check, compare the water at two different taps — if one gives hot water and the other doesn't, the cause is in the mixer.
If all taps give lukewarm water and hot water runs out quickly, the unit itself needs to be checked inside. Then it's the heating element, thermostat, or sediment gathered at the bottom of the tank.
When to repair, when to replace
Repair makes sense if the tank is sound and the fault concerns replaceable parts. Replacement comes into question when the tank is leaking, the unit is very old, or the parts needed for repair are no longer available.
For a replacement, the scope of work is affected by the installation location, the condition of the connections, and whether the new unit's size fits the existing niche. We look at these on site before taking anything apart.
What to note before calling a technician
- the heater's capacity and approximate age
- whether the water is completely cold or lukewarm
- whether hot water runs out faster than before
- whether there's moisture under the heater or around the connections
- whether the unit has switched off on its own or the breaker has tripped
Frequently asked questions
- Why does hot water run out faster than before?
- A common cause is sediment gathered at the bottom of the tank, which reduces the usable volume, or a partially faulty heating element. Both come to light during maintenance.
- Is it worth repairing a water heater older than ten years?
- If the tank is sound and the fault concerns the heating element or thermostat, repair is often sensible. If the tank is already leaking or suitable parts are no longer available, replacement is the more practical solution.