Aussie engineering pours cold water on the notion that instant hot water is a costly luxury for our bigger homes that need it

Ross and Hilde James – “Before we got the Aqueous, we used to have to wait a whole minute for hot water to do a 10-second job”

With the average Australian new house size topping 230 sq m – more than double the size of those built in the 1950s and 60s – some hot water systems are struggling to deliver their output to taps quickly enough.

That’s because hot water may have to travel five or ten metres or more to reach hot taps of the kitchen, bathrooms, wash house or flats in new or renovated properties, taking what seems like ages to arrive, while all the time flushing valuable cold water down the sink until it does finally heat up for the job at hand.

One efficient solution that appealed to retired engineer Ross James was an Australian-developed compact heater – the 10L Aqueous design from Aus J Hot Water Solutions – that can be wall or floor-mounted close to the sink, shower or utility in question to deliver near-immediate hot water where it is most needed.

The 10L and even more compact 6L Aqueous – which each cost $350 online, plus modest plumbing-in costs – are typically installed in cupboards or under floors so they can deliver hot water as needed to relieve the aggravation of householders who previously had to wait a minute to do a dishwashing job, for example, that might just take seconds to complete when the hot water eventually arrives.

Ross James says that – despite the trend to tiny houses and apartment living – there are plenty of bigger houses, such as theirs overlooking Pittwater, where the speed of hot water supply hasn’t kept up with household demands. Methodically – as befits an engineer – he researched the best and most cost-effective solution to his problem, eventually settling on an Aqueous installed under the floor of the kitchen used by him and his wife Hilde.

The installation undertaken by Ross James, complete with bypass valve for contingency use. The total cost for a high-quality job, including Aqueous, was a fraction of alternatives

The Aqueous comes with Australian WaterMark accreditation, which means that it passed extensive tests and requirements regarding its suitability for safely supplying water for human consumption.

“We looked at an instant hot water heater for about $3,000, but the Aqueous was better suited to the purpose and a fraction of the price. Even after plumbing it in, it was about $600 all up – and that includes quality fittings and a bypass valve.”

Hilde James says that, in service the new hot water supply “is great for me. Before we got it, I used to have to wait a whole minute for hot water to do a 10-second job. It got to the stage where I would put off doing some jobs until nighttime, so I could do them altogether. We were very impressed with the followup. It is the kind of service you don’t see much of these days.”

Ross James says he purchased his new unit for the kitchen “because it is a long way from my off-peak heater, and we waited too long for hot water.”

“I was able to install the unit under the house, directly below the sink. I have a couple of valves that allow me to bypass the unit in case of power failure. I installed a pressure regulator, just to ensure maximum pressure couldn't be exceeded. Of course, it has an over-pressure valve anyway, which is essential for thermal expansion.”

“The unit seems to be well built. It installed easily and was easy to set up – turn it on and set the temperature. It takes about 40 minutes to fully heat up. Now we have hot water five seconds after turning on the tap.

“I was considering installing the 6L version but went for the 10L. Good decision. I wouldn't recommend less than 10L for a normal house kitchen. About 5L is plenty to do normal washing up (mixed with some cold water gives significantly more), but, if you are using much more in one go, the temperature starts to drop.”

“We've only run short on hot water once, soon after installation. This was because I set the thermostat fairly low, and we used some hot water for rinsing before washing up. After turning up the thermostat (not quite maximum), and being sensible with rinsing, we haven't had any problems.”

“I understand from Jay that the hot water supply from a large tank could feed into this, instead of just cold water. This would give quick hot water, and plenty of it, which would have to be balanced against heat loss and greater electricity cost.”

Ross James says that Aus J Hot water Solutions Managing Director Jay King was always available for advice and follow up. “His personal service was outstanding. And it is a quality product that is very affordable – far more cost-effective than alternatives.”

“We are now talking about the Aqueous to all our neighbors around here in Bayview, because it is ideal for the big houses here, which often have long runs from the water heater to the tap.”

Since installing the first Aqueous, Ross and Hilde have now installed a second to provide water for a bathroom sink typically used only to wash hands. Because this outlet has limited use, the smaller Aqueous unit was selected, with the even more compact 6l unit again installed under the house. (As below)\

“We have used the Aqueous units because we previously had to wait too long for hot water – and we wasted lots of water waiting for it to arrive. In summary, the units in service are doing exactly what I intended.”

Aus J Hot Water Solutions ( ) offers a range of innovative gas and electric water heaters with models for domestic, commercial and recreational applications, including a 12v/240v 10-litre Duoetto water heater for recreational vehicles that delivers enough capacity and temperature range for people to enjoy civilised home comforts wherever they are on the road or the water.