Gas water heaters are common in Australian homes because they work well, are low maintenance, and are efficient. If your gas system is failing to heat the water properly, then it is time to schedule a service call. Fortunately, most causes of poor heating are easily and quickly repaired.

1. Ignitor Failure

The ignitor is what lights the gas to produce the heat in the burner that will warm the water. Most gas heaters are controlled by an electric ignition system, so an electrical short could result in failure to ignite and heat. A hot water service can inspect the ignition system and make any necessary electrical repairs. Another common ignitor issue is a clog in the fuel valve that serves the ignition system. Cleaning the valve solves the problem.

2. Dirty Burner

The burner is where ignition and heat production occurs. When the burner is dirty, the fuel may not combust thoroughly or evenly, which can lead to poorly warmed or even cold water. Dirt comes from dust and residue left behind by impurities in the fuel. It can also be due to partial combustion issues. Your service technician can easily clean the burner. They will also determine the cause of the dirt so any related issues, such as those leading to incomplete combustion, can also be repaired. 

3. Blocked Filters

Most modern heaters have a filter on the cold water inflow line. Its purpose is to filter out any minerals or other impurities in the water that could precipitate out during heating and clog up the hot water heating and delivery systems. Over time the cold water filter can be clogged with debris, particularly in areas with hard water. Your technician can remove the clogged filter and either clean it or replace it, depending on the needs of your heater model and the extent of the clogging.

4. Flow Sensor Failure

A flow sensor is an important safety device, as it only allows the ignitor to fire if liquid flow is detected in the water system. If the water isn't flowing for some reason, then the water system won't fire and create a gas hazard. This also ensures efficiency, since the ignitor won't come on unless there is actual water to heat. A failed flow sensor can lead to a false no-flow reading, resulting in no heat. Replacing the sensor should resolve the issue.

Contact a hot water service if your gas water system is leaving you in the cold.