First Issue: Why water gets hot and cold alternatively
Occurrence: mostly when there is a mixer tap and applies for standard gas geysers.
Advanced gas geysers do not have such issues at all with mixer unit taps
Possible cause: Cold water pressure too strong, causing back feed to the geyser and causing geyser to switch off. Gas geysers have an automatic systems that shuts off when there is potential danger. As such, a back feed is considered to be a safety concern and hence the geyser will switch off
Solution: turn hot water on first on the mixer, then gradually turn cold water until you get desired temperature
Install non return valve to prevent cold water back feeding to geyser
Recommendations – check that the hot water pressure is not being affected by a blockage at the geyser or along at the mixer. This is particularly true if incoming water has a significant amount of minerals, as hot water tends to cause mineral precipitation that may result in blockages
Common Gas Geyser Problems: No Hot Water
Occurrence: Mostly when water heater pilot light goes out
Possible causes: gas valve, thermocouple failure
In gas geysers, heat transfer works by means of combustion of natural gas or liquid propane gas. There is a burner inside of a gas chamber that ignites gas through a pilot light. The air that facilitates this combustion is let in through a flame trap.
In order for this system to work in a safe manner, there is a device that informs the valve to release gas or shut off gas. This device, called thermocouple, will “tell” the gas valve to open for gas supply whenever the pilot light is lit, and to shut off gas supply when the light goes off.
This means that all these components should be functional for water to heat up
A faulty or broken thermocouple will not sense that the pilot light is on, and hence will incorrectly inform the valve to shut off
A malfunctioning valve will also not be able to perform as expected and result in no gas flow
The pilot light will need replacement if it no longer works accordingly.
Some modern geysers however do not have a thermocouple. Instead, they make use of a microprocessor that accurately maintains temperature and monitors the pilot light. This system has a flashing LED to indicate that the pilot light is on
Lukewarm or Water not Hot Enough
Occurrence: when there is a faulty regulator, incorrect temperature settings or simply gas running out
Inspect thermostat setting are correct for summer/winter as case may be
Ensure gas inlet adjustment is completely open.
Inspect and ensure water inlet completely is fully open.