1 Oct 2024

Preventing Backflow in Storage Heaters: Ensuring Safe Water in Singapore and Insights from New Zealand

STORAGE HEATER

Preventing Backflow in Storage Heaters: Ensuring Safe Water in Singapore and Insights from New Zealand

Backflow, a critical issue in plumbing systems, occurs when water flows in the reverse direction, potentially leading to contamination of the water supply. In Singapore, this problem is particularly relevant when installing storage water heaters that do not comply with the SS636: 2018 standards, specifically clause 6.5.2(b), which mandates the installation of an efficient device to prevent the siphonage of water back through the inlet.

Siphonage, or backflow, can pose serious contamination risks if storage water heaters are installed incorrectly. A common issue in many HDB flats and private residences is that storage water heaters are not fitted with proper backflow preventers, thereby failing to meet the strict safety measures outlined in the SS636.

Widespread Non-Compliance

In Singapore, hundreds of storage water heater replacements are carried out annually, with 80% of the bulk going to HDB flats. Despite the importance of adhering to backflow prevention standards, over 500 shops, including online retailers, sell storage water heaters, often bundled with installation services. However, many of these installations over 90% are carried out by unlicensed handymen, which is a breach of PUB regulations.

Legal Implications of Unlicensed Installation

According to the PUB’s guidelines, it is illegal to engage an unlicensed plumber for regulated water service and sanitary plumbing work. Despite this, it has been observed that a significant number of installations are performed without adhering to the proper legal requirements, leaving homeowners vulnerable to both health risks and potential legal consequences.

Ensuring a Safe Water Supply

To avoid drinking contaminated water due to backflow, it is essential that storage water heaters are installed with proper backflow preventers, as required by SS636 6.5.2(b). We strongly recommend that the public engages only PUB-licensed plumbers for installation and maintenance work. Licensed plumbers ensure compliance with the latest safety standards, safeguarding the public water supply from contamination.

If you have any questions or concerns about the safety of your water supply or the installation of your storage heater, we encourage you to contact PUB directly via email.

New Zealand's Approach to Backflow Prevention

New Zealand has also recognised the critical importance of preventing backflow contamination in its water supply. The introduction of the Health (Drinking Water) Amendment Act 2007 has redefined responsibilities across various stakeholders, including local authorities, water suppliers, and health agencies, to ensure the safety of drinking water supplies.

A key aspect of New Zealand’s strategy is the development of Public Health Risk Management Plans (PHRMPs). These plans are required to mitigate contamination risks, including backflow, by implementing integrated, risk-based approaches across the water distribution network. This ensures that the entire supply chain from source to tap adheres to rigorous safety standards