A cold shower in the morning is one of the most common calls we get across Kuala Lumpur. Instant and storage water heaters fail in different ways, but most cases come down to a handful of causes. Some you can check yourself in a few minutes; others need a plumber or electrician. Always switch the heater off at its isolator switch before touching anything.
Quick checks you can do safely
- Is the power on? Check the heater's isolator switch and your DB box for a tripped breaker or RCD.
- Is the indicator light on? No light usually points to a power, switch or internal electrical fault.
- Is the water flow strong enough? Instant heaters need a minimum flow to switch on, so low pressure can stop them heating.
- Did it trip after a leak? Water near the unit or on the wiring is a sign to stop and call for help.
The 7 most common causes
- A tripped RCD or breaker, often caused by a failing heating element or moisture in the unit
- A burnt-out heating element, especially in older storage heaters
- A faulty thermostat or temperature cut-out that stops the heater from switching on
- Low water pressure or a clogged shower head, which stops instant heaters from activating
- A blocked or scaled inlet filter, common in areas with hard or sandy water
- A loose or leaking connection that lets water into the electrical parts
- An old unit at the end of its life, usually after many years of daily use
When to stop and call a plumber
If the RCD trips again as soon as you switch the heater on, if you see water leaking from the unit, or if you smell burning, switch it off and leave it off. Repeated tripping means electricity and water are meeting somewhere they should not. A plumber can test the element and thermostat, fix leaking connections and tell you honestly whether a repair or a new heater makes more sense.
Repair or replace?
Replacing an element or thermostat is often worthwhile on a heater that is a few years old. If the tank is rusting, the unit leaks from the body, or the same fault keeps coming back, a replacement is usually better value. FixPro MY repairs and installs instant, storage and solar water heaters across Kuala Lumpur, 24/7, with a clear quote before any work starts.