The main causes include: Depleted ignition batteries; Low water pressure or a clogged water inlet filter; A damaged or torn water diaphragm (membrane) preventing the gas valve from opening; Blocked flue/chimney triggering the draft safety sensor.

In regions with hard water, servicing the tank and replacing the magnesium anode is recommended once every 12 months. The anode protects the inner tank walls and heating element from corrosion; failing to replace it in time leads to element failure and tank leaks.