For the plumbing technicians at Whywait Plumbing listening to clients recollecting the days gone by when high water pressure was the norm are a frequent occurrence. For many high water pressure had been a bonus, especially when water was virtually provided for free. High water pressure enabled many to stand in one spot and water the whole garden or to literally pressure clean the car or driveway.
Both Gold Coast and Logan regions had high water pressure delivery, frequently in excess of 800kPa and often as high as 1100kPa. In reality high water pressures caused many problems with damage to pipes, appliances, taps, valves and fittings from water hammer which also reduced their operational life plus caused excessive noise in the water reticulation system.
Legally under AS/NZS 3500.1:2003, Plumbing and Drainage – Water Services, the relevant clause is 3.3.4 which states, “Maximum pressure within buildings – Provision shall be made to ensure that the maximum operating pressure at any outlet, other than a fire service outlet, within a building does not exceed 500 kPa.” This was further reinforced with amendments in 2010 to clause 3.2.1 which states, “The maximum flow rate from a shower, basin and kitchen sink or laundry trough outlet shall not exceed 9 L/min.”
These very clear definitions within Australian Standards create a dangerous situation that many home and building owners are unaware of. This is because they have the incoming mains water pressure set above the maximum legislated operating pressure of 500kPa level for most connected plumbing fixtures. These plumbing fixtures include dishwashers, washing machines, mixer taps, refrigerators with water purification and hot water systems.
Having excessive water pressure can cause you more problems than you may be aware of. Aside from damage to pipes, appliances, taps, valves and fittings from water hammer which also reduced their operational life plus caused excessive noise in the water reticulation system, you may also be voiding your property insurance and manufacturer’s warranty on any number of these expensive household appliances.
Most insurance policies and appliance warranties are void if your water pressure is above the recommended operational levels. This will always come back to the requirements of Australian Standards which is of course 500kPa.
Most hot water system warranties are void above 500kPa once again with the reference point being the requirements of Australian Standards. Many people are fooled into thinking they have a compliant system as they have pressure limiting valves installed. In reality the majority of these valves over 3 years old are faulty and in need of replacement.
As council water retailers will not guarantee supply pressures the onus is back on home and building owners to ensure they are compliant with Australian Standards. Most homes and buildings constructed since 2003 have pressure reduction valves installed after the water meter but these frequently require recalibration. Homes and buildings constructed before 2003 seldom have a pressure reduction valve installed which means they are susceptible to the fluctuations in water supply pressure.
If you think a flooded house cannot happen to you then read the story Faulty Plumbing Will Flood Your Home where faulty piping in the ceiling flooded part of a home and resulted in water damage in excess of $50,000. Luckily this homes water pressure was reduced to a compliant level of 500kPa and their insurance policy covered the damage.
If you are unsure of what your water pressure is and whether your system is compliant in regard to your insurance policies then contact Whywait Plumbing Services now to carry out a comprehensive analysis of your incoming water pressure.
