The Takagi T-K-Jr Tankless Hot Water Heater – A Product Review

Let’s take a brief look at the T-K Jr. the smallest water heater in the Takagi line of tankless water heaters.

According to Takagi, it can meet the hot-water needs of a small home or apartment with one or two bathrooms, as well as small commercial applications.

Takagi claims it was designed to do anything a standard 40-gallon tank-type water heater can do. The T-K Jr. works with both hydronic baseboard and radiant floor heating. It has an energy efficiency rating of .81 when burning natural gas and can provide 3.8 gallons per minute with a 60 degree temperature rise. The maximum input is 140,000 Btu.

When the water heater detects a flow of at least 0.75 gallons per minute, the heater turns on. While The computer in the controls monitors the water temperature, flow rate and gas flow.

When the burners ignite, a lamp comes on telling you the tankless water heater operating normally. The internal computer controls the gas valve and controls the water flow to maintain the preset water temperature of the water at the outlet
While reading through the owner’s manual, which you can find online at Takagi’s site, I ran found the following statement:

“The unit should be checked once a year or as necessary by a licensed technician. If repairs are needed, any repairs should be done by a licensed technician. The following systems and parts should be checked at least once a year:
1. Venting system
2. Burner
3. Manual operation of the pressure relief valve to ensure correct operation.
4. Periodic cleaning of the water filter (figure above).
5. Heat exchanger. Remove the thermistor and check for a mineral coating. A mineral
coating on the thermistor requires flushing the heat exchanger with a de-scaling
solution. Scale build up will void your warranty and shorten the life of your water
heater.”

You might have to add the cost of a yearly maintenance check to the costs of your tankless water heater, and that could reduce the savings from your tankless water heater.

Elsewhere in the Takagi site I read this:

“8. Water hardness may affect the water heater. Water heater may be damaged. The warranty will not cover damage caused by water quality.”

It’s something for you to think about if you live in a hard water area.

The Takagi T-K Jr requires a 110 Volts to operate the controls, so if there is a power failure your tankless water heater won’t be able to provide you with hot water.
The T-KJR can be used for space heating, and potable hot water heating at the same time.

The owner’s manual includes information on how to use the hot water heater for baseboard and for radiant heating applications and comes complete with diagrams of typical systems.

Turn your hot water plumbing green with an energy efficient Takagi tankless hot water heater.

Easy Home Improvement Project – Go Green with Your Plumbing

Looking for an easy project that you can do to improve your home? How about going green with your plumbing? By making your home more energy efficient and water efficient you’re are improving the resale value of your home and providing yourself with reduced water and energy bills and added convenience.

If you have to wait for an extended period of time to get your hot water you are a good candidate for one of the many instant hot water systems. Most don’t really provide you with “instant” hot water, but can considerably reduce your wait time, and can even nearly eliminate running water down the drain while you wait.

There are a couple of retro-fit friendly instant or more appropriately fast hot water systems that are easy to install with no major changes required for your plumbing layout. Although these fast hot water delivery systems install under the sink, they are not to be confused with under the sink water heaters. They make a good one-afternoon home improvement project for almost any skill level. If you can change a supply hose you can install one of these systems.

There are basically two types of systems, luke-warm circulating systems like the Laing Autocirc1, and the RedyTemp, and hot water demand systems such as the Metlund system and the Chilipepper pump.

The warm water circulating systems are small pumps designed to circulate the water from the water heater through the piping and on back to the water heater. When the pump senses the temperature has reached the lower set point, about 90 degrees, then it turns on until the pump senses the upper temperature, about 100 degrees, when it shuts off the pump. The system does this over and over keeping the water in the piping warm.

You end up paying for all that heat energy it takes to keep the piping warm. You also no longer have cold water in your cold water pipes. Now it’s warm.

The second type of system is known as a hot water demand system, and the pump only pumps the water to the fixture when you demand it by pressing a button. Hot water demand systems make a better home improvement project because they provide even more convenience and use less energy than the recirculating systems and will really add to the green aspects of your plumbing system.

Again, the pump mounts under the sink and is easy to hook up. With the demand system when the hot water reaches the pump the pump shuts off so you don’t end up with hot water in the cold water pipes.

Demand systems don’t run very long or very often so they typically use about $1.00 per year in electricity, and you don’t run any water down the drain waiting for hot water. They don’t use any more energy than a system with no pump since they only fill the pipe between the water heater and the fixture, just like if you ran the faucet.

If you’re looking for an easy home improvement project you can complete in a weekend, one that will add value to your home, and will provide you with lasting benefits like faster hot water, water savings, and energy savings, then install a demand system today!

Going Green? – Water Conservation Products

What is green plumbing? Well, green plumbing when applied to residential plumbing layouts, would mean plumbing that reduces your energy and or water wastage; an efficient plumbing system.

There are a variety of products out there that can save you water, but some are counter productive and some are a pain in the you-know-what. Others are certainly worthwhile and can even save you money.

The biggest factor involved in water and energy wastage is human behavior. It’s our behaviors that waste the most energy and the most water. We all do it… leave lights on, leave water running when not necessary, linger in the shower… Going green seems to often lead to less convenience. But humans are after exactly that… convenience. That’s why microwave ovens, took off. Dishwashers, washing machines, trash compactors, automatic sprinkler systems, it’s all about convenience.

Some water conservation products address these behaviors. Low flow fixtures reduce the rate at which water flows from a fixture, so we use less water when we leave it running. This can be an inconvenience though, when you have to stand there and wait longer to fill up that pitcher or sink. Low flow toilets that don’t always work with one flush.

There are numerous “gray water” systems that reclaim waste water like from your washing machine to use in flushing toilets or watering the lawn.

It’s not hard to find water saving appliances such as dishwashers and washing machines. Probably all of them now at least have water conservation cycles or modes. I recently was talking to a guy who had just bought a new Bosch water conserving dishwasher. He was having a problem because the dishwasher didn’t draw a high enough flow of water to turn on the water heater. To get clean dishes he has to run hot water in the sink while the dishwasher fills. So much for water conservation.

There are some water conservation products which do offer both convenience and save water. The Chilipepper hot water demand system is one such water conservation product. It gets you your hot water faster and you don’t run any water down the drain. The pump is very efficient consuming less than $2.00 per year in electricity to operate. Not only are you saving water and energy with the Chilipepper, but you are also reducing your carbon foot print.

Every gallon of water that you do not dump down the drain is one gallon less sewage that has to be treated and pumped etc which in turn uses less energy and thus results in reduced green house gas being released into the atmosphere.

Don’t confuse the Chilipepper hot water demand systems with one of those “luke warm circulating systems” on the market like the Laing Autocirc, the Grundfos Comfort System, and the Watts Premier.
These systems circulate warm water through the hot water piping and the cold water piping, but in doing so consume a lot of energy making your water heater work harder and costing you money. You also end up with less than cold water in your cold water lines and you must purge those lines of the lukewarm water to get cold water from the faucet.

Tankless water heaters typically take longer to get hot water to your fixtures wasting more water than hot water systems that use tank type water heaters. The good news is the Chilipepper works with any brand of tankless water heaters including Rinnai water heaters, Takagi water heaters, Bosch water heaters, Rheem water heaters, Noritz water heaters, and all other brands too.

So go green and install a hot water demand system. It’s a very earth friendly thing to do. You will feel good about what you are doing for the planet and you get the added convenience of fast hot water!

Slow Hot Water

I got this email regarding slow hot water and thought I would use it and my answer as my blog for today, so here it is.
Hello,My Dad wants to install new copper piping throughout his 2200 square-foot 2-story house. He is very concerned about 'slow hot water' and has decided he needs 1-1/2" insulation on the copper pipes instead of the standard 1/2" insulation.

He is calling around the country looking for that 1-1/2" insulation - and to Canada! He's found a plumber willing to install it for a higher price.
Do you have any studies that compare 1/2" insulation on copper pipes versus 1-1/2" insulation, and what the cost/benefits would be? And also, I think your pump solution sounds great, so could you show a comparison between your pump solution with the standard 1/2" copper pipe insulation versus no pump and 1-1/2" copper pipe insulation?

He has a regular tank water heater. Does he need to swap out his water heater?Thank you for your help,
My slow hot water answer

Typically pipe insulation is used for energy conservation purposes although adding insulation will reduce the amount of time it takes to get your hot water slightly.

The speed of the hot water is most affected by the flow rate of the fixtures and the diameter of the piping.

The speed or velocity of the water is dependent on the flow in gallons per minute and the pipe diameter. The larger diameter the pipe the slower the velocity and the longer it takes to get hot water.

Generally speaking it takes about 45 feet of ¾” inch diameter pipe to hold a gallon of water and about 70 feet for ½” diameter pipe. With a flow rate of 1 gallon per minute, the water in the ¾” pipe will flow 45 feet in about 60 seconds, and for the ½” diameter pipe the water will flow 70 feet in that same 60 seconds.

Since the flow is restricted by the fixtures, it will take longer to get hot water with the larger diameter pipes.

To get hot water to the shower fast, turn on the water in the bathtub full blast, it has the highest flow rate of any bathroom fixtures!
The second most important factor is the amount of heat that is pulled out of the piping material as the water travels to the fixture. That is where the pipe insulation comes into play.

If you had perfect pipe insulation and no heat could leak from the pipes, you would always have instant hot water. But there is no such thing as perfect insulation, and the heat will leak out fairly rapidly no matter how much insulation you use.

Pipe insulation is normally only used when a continuous hot water circulating system is being incorporated. It doesn’t really save energy, since the hot water will cool off very rapidly even with heavy amounts of pipe insulation. The reason 1-1/2” insulation is so hard to find is that it is a waste of money.

I don’t know of any studies that involve 1-1/2” thick pipe insulation.

Slow hot water delivery time is also related to the water velocity in another way. When water velocities are slow, the hot water traveling through the pipe travels much like a bullet would through the pipe.

Higher velocities cause laminar flow where a smaller diameter flow of water travels through the center of the pipe and the water in contact with the pipe walls doesn’t flow, getting the hot water to its destination even more quickly.

Plumbing layout is very important.

If you are planning on using a pumping system then the plumbing layout should be looped from fixture to fixture instead of a layout with T connections and lots of branch runs. That way a single pump can supply fast hot water to all of the fixtures.

About the water heater

I presume you mean should he replace is tank water heater with a tankless water heater? If so then the answer is no. Tankless water heaters take longer to deliver hot water since they have to turn on and start heating the water while the tank type water heater has already hot water to start the journey.

Tankless water heaters typically take 10 to 20 seconds longer to deliver hot water than tank type heaters.

So in conclusion, unless you live in a very cold area using pipe insulation will have a very small affect on how slow or fast your hot water delivery is. Increasing the pipe insulation beyond ¾” thick will most likely have no measurable effect.

Smaller pipes will deliver the hot water faster than large diameter pipes for a given flow rate.

Pumps such as the Chilipepper pump at a faster rate than typical flow rates available from the hot water fixtures.

For true "instant hot water" use a full time hot water recirculation system and insulate the pipes with at least 3/4" thick insulation.