Do it Yourself: Re: [DIY] New Hot Water "System"

02 November 2013

Re: [DIY] New Hot Water "System"

There is nothing wrong with POU tanks as long as they are not the only source of hot water. Their intended purpose is to provide instant hot water as an integral part of a total hot water system. I have seen those who tried to use POU heaters as their only source and the results were not very satisfactory as they were constantly being required to heat cold water which was sometimes very cold. When installed in the hot water line and used for their intended purpose they work very well and actually cut down on overall water and energy consumption.

If I lived in the south, which I do not and probably never will, I would attempt solar hot water, but I would be very hesitant to apply full water pressure to any solar system. There needs to be a separate transfer loop and circulating pump just for the solar system, and I don't know of anyone who presently offers a factory certified tank with a circulation loop already installed. In any area where freezing is a possibility the solar loop needs to be filled with some form of antifreeze and this must be certifiably kept separate from the main water system for obvious health and legal reasons. Perhaps no one is willing to assume this degree of liability at affordable costs.

Dale in the Flatlands. "Why waste time learning when ignorance is instantaneous."

Ron Johnson wrote:

Thanks for the info. I never trusted the POU tank, but I haven't been keeping up with the new products. As time goes on, I'm sure the technology will get better end better.

Speaking of which, I was wondering if anyone out there has used solar water heating and what the pros and cons are. We own a few apartment buildings and I've always thought it would be good to use it there, but I'm leery about that, too.

To: DoIt_Yourself@yahoogroups.com
From: dalu@hbcomm.net
Date: Sat, 2 Nov 2013 00:24:11 -0500
Subject: [DIY] New Hot Water "System"

The observant reader will notice that I wrote "system" in the subject line and so I will explain. Our hot water tank was 20 years old and still working fine but I decided that it was time to change while I could until waiting until I had to. I was well aware of some of the features of the tankless systems that I did not particularly care for when ordering our new heater late last summer. The wife was going to be gone for the month of October and I thought that would be a good time to install the replacement. It also gave me time to examine the system and make my decisions before starting.

There have been numerous improvements in the last several years since I installed my first tankless system for a customer. Ours was ordered with the remote which I knew we would not be happy without as the older systems failed back to the lowest temp in the case of a power outage requiring the customer to go down to the unit to reset the temp. The unit I settled on was a Rheem as were the several others I had installed because number one they are made in America and I have found their service and parts response to be excellent. It turns out that the system now has memory and after a power disconnect it returns to the previous setting. This unit is also high efficiency and will condensate if the exhaust run is over a certain length, ours however is not so I did not install the condensate drain.

I knew my wife would not be happy with either the lag in hot water or the tepid temperatures at the kitchen sink that is typical of these tankless units so I also installed a 6 gallon point of use electric tank in the hot water line and was able to place it in the basement directly under the kitchen so that it only takes about 8 oz of water before she has piping hot liquid. She likes her kitchen and dishwasher water at or above140+ and so with this setup she is able to have very hot water in the kitchen while leaving the remote control set at 104 to 108 for bathing and washing. The remote, which by the way is the only control provided for the system, was mounted in the bathroom.

For those who might be considering a tankless water heater, you may as well plan on adding a point of use tank in the beginning. These are available in several capacities ranging from 2 to 6 gallons and since they are installed in the hot water line never actually see cold water. Some may opt for a circulating pump but be aware that either a switch must installed at the primary point of use or a timer that is preset to run the pump during normal hours of expected water needs. One is a pain in the neck and the other seems to defeat the savings one might expect to incur from a tankless system, hence my decision to opt for the additional point of use tank which was in fact about 1/2 the price of a circulating pump and timer system.

I also noticed in reading the installation instructions that someone has finally decided to admit that these units will need to be occasionally flushed using a mild acid to remove scale build up and so the service connection and associated valves are recommended during original installation. Rheem also offers a pump and container to be used when servicing. I installed the isolation valves on both hot and cold water lines but opted to add the service valves and connections later, because ours is installed using plastic pipe and easily modified as required.

Our tankless unit is gas and the point of use unit is 120 vac at 1500 watts or 12.5 amps. I deliberately started the point of use heater with cold water and it had reached its set temp and shut off in less than 15 minutes. We have yet to even begin to see a difference in water temp at the kitchen sink. The POU heater is a brand I had never heard of but is a subsidiary of Bosh and appears to be very well constructed although made in China, but then what isn't.

Dale in the Flatlands. "Why waste time learning when ignorance is instantaneous."