As we have seen in the recent Straits Times article, “Rupture of storage water heater at Marine Parade”, storage heaters will seriously malfunction if not installed well.
Terrible incidents are usually triggered by a combination of many small factors that have gone wrong. What went wrong?
The three safety devices in storage heaters prevent ruptures.
Safety Device 1. Thermostat
Every heater has a thermostat in it. A thermostat is an electronic device which helps to regulate the temperature inside your heater tank. Safe operational temperatures for water heaters are between 50 to 75 degrees.
The thermostat will stop the heating element inside the heater from working when the temperature reaches 75 degrees.
What to look out for:
You will know that the thermostat is not working when the heater does not produce hot water at all, despite the main heater switch (with red light) being on
Safety Device 2. Thermal cut out
In addition to the thermostat, a thermal cutout is also fitted in the heater. In case any fault occurs and the tank temperature exceeds the highest preset temperature (93 degrees), the switch instantly cuts off the live wire for the user’s safety.
What to look out for:
If your heater trips, a service team should be going up to check that the thermal cut out is reset and working well.
Safety Device 3. Pressure relief valve
The last safety device is one most often overlooked by contractors because it is an external fitting and not in-built in the water heater. The pressure relief valve is a safety valve that is mandatory for every storage system. It helps to relief pressure in the tank throughout the daily operation of the water heater. It does so by releasing tiny droplets of water.
What to look out for:
Ensure your relief valve is not blocked. Tiny droplets of water are normal but it is not normal to see water flowing out of your valve like a tap. Call your service hotline if anything like this happens.
Observe the 3 checks above to ensure the relief valve is working normally and that the drainage tube is not blocked and is downward facing. If there is a blockage in the tube, pressure will not be released from the tank.
How do the safety devices prevent tank ruptures?
Every time water is heated, the temperature in the tank increases and the internal pressure increases. Each of the safety devices in the heater reduces the internal tank pressure by:
Ensuring the temperature does not rise past 75°C, and
Releasing excess pressure
The constant release and regulation of tank pressure keeps the tank ‘healthy’ and rupture free.
Use an experienced installer
Most water heater problems are caused by incorrect installation by unfamiliar parties. Instead of following proper installation procedures, installation mistakes of bypassing the thermostat and thermal cut out (2 of 3 of the safety devices) will cause situations similar to the Marine Parade apartment rupture.
Digital water heaters
If you are using a digital water heater, these systems boast an additional safety function. Digital water heaters come with a control panel which serves as a ‘brain’ for the heater. The control panel ‘brain’ constantly scans the heater for any faulty internal devices.
The system automatically reflects an error message on the panel that isolates the heater fault. If the faulty component is crucial to the safety of the user, the heater will be shut down.In addition, you can always monitor your temperature levels to ensure nothing is amiss.
Beware: Poor Installation Techniques and Maintenance
Quality storage heaters are extremely safe and reliable. In Singapore especially, they are tested under rigorous standards by a third party before being passed to sell in the open market. Any faults arising from their use are mostly due to poor installation or maintenance.
Storage heaters are still the leading choice for hotels, clubs and private residences today.
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