The Science and Art of a Water Heater

Ok, a follow-up from my previous post. I visited the Bennington office at TechPlace 1 to solve my water pressure and "slow" hot water problem. Robert Lee, the guy in charge of technical support was very thorough and he gave an excellent demo of how the C600 works.

They actually set up a working model at one corner, and he proceeded to explain to me how fast the water will be heated up by the C600 (C600 multi-point instant) water heater. For demonstration purposes, they didn't hook up long pipes (from 5 to 10m long) to simulate the common and MBR (master bedroom) bathroom water points. But it did show how fast hot water will start flowing once the heater is triggered by water pressure. It took about 3-4 seconds - roughly the same as my current single point instant heater at home. It works, point taken. But what about my slow hot water problem?

Well, earlier, their onsite engineer has already checked that it is not due to the debris in the C600's copper tank. (Note: it is always a must for the installer to flush out the water in the pipes before connecting to the inlet of the C600 to prevent accumulated dust or other contaminants from getting into the heater tank).


So, anyway we already established that whether it is using instant heater or storage heater, the hot water needs to first travel along the pipes (even for HDB flats where the MBR and common bathroom are practically side by side), and so it will still take time for the water inside to be displaced before you can feel the hot water. I figured the water was probably displaced around 1 metre worth of pipes per second (okay I have no scientific measurements to confirm this, and going by gut feel here), so the 10 seconds initial wait was logical. But, it would probably take another 2-3 seconds per metre worth of pipes I reckon for the hot water to completely displace the pre-existing water, so you'd look at 15-20 seconds in the afternoons for the water to feel hot, and a 20-30 seconds wait in the evening/night. However, there is another hidden factor at work.

In my case, the large shower heads (on the right side in the picture above) from the original HDB fittings means that (1) more water needs to flow through to get satisfactory pressure (2) you waste more water. I also deduced that when there is more water rushing through the C600, besides wastage, it also means less time for the water to heat up fast - so the hot level doesn't reach the optimal hot level fast. So, therein lies another hidden factor - the size of the showerhead. Size, it seems, does really matter. ;-)

Robert also explained to me that his company took pains to scour the market to find the showerheads that meet their stringent requirements. So, I bought 2 of the same smaller type "standard" showerheads that come bundled with their other instant single heaters. (Note: the C600 doesn't come with showerheads as it is a multi-point heater and you're home should have the separate shower set installed). He also mentioned that some countries require hand shower to be tested to specific water saving standards and what they supply comply with such standards. When I tried them, I could feel sufficient water running through in strong jets, but yet, the total amount of water dispensed is surprisingly modest compared to my old ones. See picture below of the 2 types of showerheads that Bennington has. I choose the smaller one on the left.

When I got back, I was so happy that I made the trip to get the showerheads. The whole system from C600 to the showerheads really works! After I replaced the showerheads, I turned on the shower in the MBR, and strong jets of water came forth. Hot water started coming after around 10 seconds (you can't escape the physics portion) and it really could get hot unlike before! After a while, I even had to turn down the knob a bit to adjust it to lukewarm coz it got quite hot (but to be objective that's like after half a minute while I was testing, so I guess the whole system of heating, water flow and rate of expulsion from the shower has reached optimum). At least it works, and works well, unlike some hotel rooms where I had stayed before.

With a small turn on the showerhead, I got the "spa" mode where the water comes out in a few thicker and pulsating jets - or more like water massage mode - as it beat down on my palm. Finally, I really like the "mist" mode when you turn it all the way to one side. The showerhead becomes like tiny sprinklers and you can feel both warm mist and wind blasting out. Very therapeutic, and I think the ladies would love it.

So, now the water pressure from the shower is strong - in fact, I may turn it down the volume at the water mains so that the jets are moderately strong. In fact, I probably should have gotten the other bigger showerhead that Bennington has. Unfortunately, it only comes in the normal and "spa" mode. Would have missed out on the "mist" mode. I guess that's the "Art" part of it to appreciate how things work, and get the maximum satisfaction out of this product. I also love the fact that its more environmentally friendly, as the water-saving feature of their showerheads means I can indulge in the shower slightly longer without the guilt or a big water bill at the end of the month.

Oh, I forgot to mention that Robert explained that their heaters are tested by PSB, and besides being protected from current leakage by using earth connection, there are 2 safety thermal cut-off protections or what I term as "fail-safe" features in the heater. One fail-safe kicks in at the heater when it rises about 60 degrees to act to prevent overheating so that you won't get scaled. The 2nd fail-safe kicks in if it really rises above 90 degrees or there is major expansion to prevent any form of "explosion" or the copper tank cracking.Most heaters come with only one such thermal cut-off protection. While shopping for my lights and heater, I heard there is another brand of multi-point instant heater on the market by Rxxx, but the news is that the OEM manufacturer has apparently closed down. So, price may be low as they are clearing stock, but customer service is in question. Robert also mentioned that their C600's copper tanks are sealed using a higher temperature process called "blazing" (above 600 degrees?) which effectively makes the copper tank bonded stronger. The other manufacturer uses normal welding which will leak through prolonged use or above 500(?) degrees.

I'm glad I bought this C600, and will recommend to whoever is looking for a good balance of function, safety and reliability.

P.S. I apologise for some of the blur pictures - it was warm and misty in the bathroom. ;-)