Hot Water Recirculation System? Replace it with a Demand System!

Many residential single family and multi-family homes built in the past have full time hot water recirculation pumps and systems installed. This no doubt saves a whole lot of water, but it also wastes a tremendous amount of energy.

Hot water recirculation

Recirculating systems were typically used in larger homes, say 3,000 square feet and up. Long pipes mean long waits, and if you could afford a big house you didn’t want to have to wait forever for the hot water to arrive.

Full time recirculation systems slowly circulate the hot water through the hot water piping keeping the water in the pipes hot for instant use. Turn on a faucet and within a second or two you have hot water. It’s a great convenience, but there is a penalty to pay.

Wasting energy

Your hot water plumbing becomes a giant heat exchanger causing your water heater to fire more often and longer. Not only does this waste a huge amount of energy, but it substantially increases the wear and tear on your water heater.

Even if you heavily insulate the pipes and put the recirc pump on a clock timer, you still end up spending a lot of money for that wasted energy. It’s not helping your carbon footprint either.

Hot water demand systems

A demand hot water system on the other hand will still save you thousands of gallons of water each year, and it won’t waste any energy. Demand pumping systems typically use about $1.00 per year in electricity to run the pump. This is because the pump only runs for a few seconds and only when you really want hot water.

With a demand system, you simply push a button when you want hot water, and that starts the pump. The pump sends the water to the fixture at a faster rate than if the faucet was just run. When the hot water reaches the fixture, the pump shuts off, and when you turn on the faucet you have instant hot water. No water was run down the drain.

Installation is easy. Simply remove the old pump and replace it with the demand pump. Buttons can be hard-wired from the points of use, or wireless switches can be used.

You will still save water, and you will save energy and extend the life of your water heater. Best of all you will feel good every time you use your hot water knowing that you are doing your part to reduce global warming!

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.

A Water Heater and a Demand Pump - Instant Hot Water for Less Than $200

If you want instant hot water from your water heater when you turn on the faucet, then you want a demand pump. A hot water demand pump system is not the same as a recirculating or recirculation pumping system.

Recirc Pumps

Recirculation pumps, often referred to as “recirc pumps”, are for circulating a small flow of water through the piping system continuously to provide you with instant hot water when you turn on the spigot. Although you get instant hot water when you turn on the faucet, the system wastes a tremendous amount of energy since the hot water piping acts like a giant radiator. The water heater has to work much harder to replace all the lost heat and that costs you money. It also produces more green house gasses.

Demand Pumps

Demand pumps only pump hot water through the piping to your fixture when you “demand” it by pressing the pump’s start button. You won’t use any more energy than normal since you are only filling the pipe with hot water, just like you would if you turned on the tap and ran the water down the drain while you waited.

The pump typically runs for less than a minute, and thus uses very little energy of its own. The pump usually uses less than $2.00 per year in electricity.

Tankless Water Heaters

Although normal recirc pumps and recirculation systems will not work with tankless water heaters, demand pumps will, if they have enough power to turn on the heater. The Chilipepper pump has enough power to turn on any tankless water heater on the market. Others such as the Metlund D’mand System pumps have several models with different amounts of power, and some models will turn on some heaters. Be sure to check before you buy!

Tankless hot water heaters require more time to get the hot water to your fixtures since they have to heat the water first. Typically 10 to 20 seconds longer. That means you run more water down the drain waiting. With tankless hot water demand pumps are even more beneficial than with storage type water heaters.

A Green Plumbing Product

By installing a hot water demand system you not only get the convenience of fast hot water, you reduce your carbon footprint. It takes energy to pump and treat both the potable water in your residential plumbing, and the resulting sewage water from running it down the drain. By using less energy for pumping and treating the water, you release less pollution and green house gas into the atmosphere.
The Chilipepper hot water demand pump costs well under $200.00, and will pay for itself, often in a year or so.

Metlund D’mand System Pumps for Water Heaters – Flow Rate Truth

Metlund D’mand System Pumps for Water Heaters – Flow Rate Truth

I’d like to use today’s blog to answer an email we received which has a number of questions that are asked quite frequently. Maybe if I publish the letter and my answer, I won’t have to answer it again as often?

Here is the email: I am interested in your on demand hot water device chiefly because my bathroom sink and shower are on the opposite side of the house from the water heater, and a tremendous amount of water is wasted waiting for hot water to arrive at those faucets. I have looked at your on-line info and have several questions.

1) I am concerned that the chilipper reports only a 4 gallon per minute flow rate, as opposed the the 8 gpm, 14 gpm, and 28 gpm for the various Metlund models. How is it that one could expect a decent flow of water in the shower and faucet with such a low gpm? I confess, I do not under stand the comments about backflow and feet of head, so maybe that factors in some how

.2) I talked to my handyman (he would be the one to install it) a little about hot water recirulating systems, and he warned me about the ones that ar on all the time, wasting energy. My schedule varies a lot, so having the system on a timer would not work well for me. Therefore, I want to confirm that the Chilipepper operates with what sounds like a simple push of a button or flick of a switch?

3) If I forget to push the button, will the hot water faucets default to their ordinary function, where I would simply have to wait the usual time for the hot water to arrive?

4) I live in an area that has very had water - lots of minerals. What hazards would that pose to the Chilipepper and what maintenance would be necessary to cope with the problem of hard water deposits?

5) I only have one bathroom at this time. It is an eventual goal to add a second bathroom. Would one put another Chilipepper under the sink of a second bathroom to maximize function?I may come up with more questions later, but these were the ones that came to mind initially. Thank you for any information you can provide.Answering the questions in the order asked:

1. Actually I think we say 3 gallons a minute for the Chilipepper. The Metlund site is miss-leading. What they are giving you is the maximum amount of flow the pump can put out if it is not hooked up to anything.

It takes pressure to push water through pipes, and their pumps don't have enough power to develop the required pressure.

Even the Metlund S-02T doesn’t come close to having the power of the Chilipepper pump.Metlund does not recommend the smaller S-50T pump for use with any tankless water heater since it doesn't pump enough flow to turn on the water heater, even if it is less than 50 feet away.

Why? Because it won’t even pump enough water through a tankless water heater to turn it on… typically ½ gallon per minute. So if their pump is rated at 8 gallons per minute why won’t it pump even a ½ gallon per minute through a tankless water heater?

The answer of course is their pump doesn’t produce enough pressure to push that much water through the small diameter tubing in a tankless water heater’s heat exchanger.

I've written a comparison between the Metlund pumps and the Chilipepper pump if you want to read about it. http://www.chilipepperapp.com/Artcls40-Metlund-pump.htm

If you want to read about how my partner and I invented the Metlund system before we got ripped off you can read about it too.http://www.chilipepperapp.com/Artcls31-D-mand.htm

2. Yes, the press of a button turns it on. Then it turns itself off when hot water reaches it.

3. When the Chilipepper is not running, your plumbing system doesn't even know it's there. There will no change in your plumbing systems operation.

4. There are no hard water problems with the Chilipepper and no maintenance is required.

5. It all depends on your plumbing layout. Running the Chilipepper has the same result as turning on the hot water faucet until hot water reaches it and then turning it off. (Except it doesn’t run water down the drain)So you can test your plumbing.

Pretend you are a Chilipepper and turn on the hot water faucet until hot water gets there, and then turn it off. Now go to another fixture and turn on the hot water. If it shares the main hot water run you will get hot water faster.It depends on your residential plumbing layout.

In my house it takes over a minute to get hot water to the kitchen sink. But if I run the Chilipepper which is in the master bath upstairs, and then turn on the kitchen sink faucet I get hot water in 7 seconds. So I have a remote switch at the kitchen sink.

And yes, if need be you can run multiple Chilipeppers in one home.Thanks for your interest in our product!

Bill – The Hot Water Guy

State Industries Storage and Tankless Gas and Electric Hot Water Heater Website.

A Quick Look At State Storage and Tankless Gas and Electric Water Heaters

OK, that’s it. I’ve looked at the State water heater site, and it is just the same as all the rest. Besides the ones I’ve recently blogged about, I’ve also written articles about Rinnai, Takagi, Noritz, and Bosch tankless water heaters. You can see the articles here: Bosch Noritz Takagi Rinnai

While reading through the manual for one of the tankless water heaters I ran across this tid-bit, and I’ve seen it with other brands of tankless hot water heaters too.

An “LC” or “00” error code indicates the unit is beginning to lime up and must be flushed. Failure to flush the appliance will cause damage to the heat exchanger. Damage caused by lime build-up is not covered by the unit’s warranty. After flushing, reset the LC fault code by turning off the power to the unit and turning the power back on.

Here is what you need and instructions on how to flush the lime out of the tankless water heater…

Circulating Pump
5 gallon pail of virgin, food grade, white vinegar (or virgin, food grade, citric acid).
Cold Water Line
Hot Water Line
In-line Filter

1. Disconnect electrical power to the water heater.
2. Close the shutoff valves on both the hot water and cold water lines (V3 and V4).
3. Connect pump outlet hose (H1) to the cold water line at service valve V2.
4. Connect drain hose (H3) to service valve V1.
5. Pour approximately 4 gallons of virgin, food grade, white vinegar or citric acid into pail.
6. Place the drain hose (H3) and the hose (H2) to the pump inlet into the cleaning solution.
7. Open both service valves (V1 and V2) on the hot water and cold water lines.
8. Operate the pump and allow the cleaning solution to circulate through the water heater for at least 45 minutes.
9. Turn off the pump.
10. Rinse the cleaning solution from the heater as follows:
a. Remove the free end of the drain hose (H3) from the pail.
b. Close service valve, (V2), and open shutoff valve, (V4).
Do not open shutoff valve, (V3).
c. Allow water to flow through the heater for 5 minutes
d. Close service valve, (V1), and open shutoff valve, (V3).
11. Disconnect all hoses.
12. Remove the in-line filter at the cold water inlet and clean out any residue. Place filter back into unit.
13. Restore electrical power to the water heater

Boy doesn’t that sound like fun? Something to consider when you are trying to choose between a storage water heater and a tankless unit.

State water heaters has some electric water heaters that have 3 inch thick insulation and have an energy factor of .94. I think that is the highest I have ever seen for an electric storage type water heater.

Not much else of interest at the State site, so that’s it for now.

I think I will try to find a new topic for my next blog. I am all water heater’d out.

Bill the Hot Water Guy

General Electric Water Heaters, Storage, Heatpump, and Tankless Water Heaters

G.E. Water Heaters and Web Site

One would think that GE, as big and wealthy as it is, could do better than number 15 in the Google search results, but that is where it is.

The first thing you see when you arrive on the home page is GE’s new “Hybrid” water heater… a heat pump water heater. It’s not on the market yet, but is supposed to be available later this year, I think it said November.

The heat pump is mounted on what I presume to be a standard electric water heater and the controls allow you to run it in several modes, like heat pump only, heat pump with electric assist, and electric only etc. There is a vacation mode too.

GE’s heat pump water heater has an impressive Energy Factor of 2.3! That is the best I have ever seen. So if you really want a green plumbing system, at least the hot water part, this is the heater for you!

GE Tankless water heaters

While I was reading up on all the tankless water heater hype I ran across these statements:

“Care for your water heater should include evaluation of water quality. If the water exceeds the target levels provided in the table, you should treat or condition the water.

If you are in a hard water area, it is recommended to install a GE water softener prior to the water heater.”

Apparently scale buildup can ruin your tankless water heater and can even void the warranty!

Here are the maximum levels allowable without treatment to keep your warranty valid.

* Source: Part 143 National Secondary Drinking Water Regulations

MAXIMUM LEVEL

Total Hardness Up to 200 mg/L (12 grains)
Aluminum* Up to 0.2 mg/L
Chlorides* Up to 250 mg/L
Copper* Up to 1.0 mg/L
Iron* Up to 0.3 mg/L
Manganese* Up to 0.05 mg/L
pH* 6.5 to 8.5
TDS (Total Dissolved Solids)* Up to 500 mg/L
Zinc* Up to 5 mg/L

So if you live in a area with hard water you might want to get it tested before you purchase that tankless hot water heater… you might need a water softener as well.

Standard Gas and Electric Water Heaters
Like the other water heater sites, the GE site has no shortage of models. I really like the search functionality they have though.

You can search by fuel type, size in Gallons, length of warranty, and tank diameter. You are presented with all of the models that meet your criteria. Then you can sort them by price. Very handy if you are trying to choose between the 64 models they carry.

I Checked out what I think is the most expensive 50 gallon electric water heater… the Model #: SE50T12TAH

Here are the specs:

Brass drain valve
Heavy duty anode rod
Double 5,500 Watt Heating Elements
Stainless Steel Upper Heating Element
Energy Factor 0.94

Great energy factor and the 5,500 watt heating elements are the biggest I’ve seen anywhere for residential water heaters.

The GE site is useless for trouble shooting information.

I didn’t see anything else of particular interest, so it’s off to find another water heater site with storage and tankless water heaters to check out…

Bill the Hot Water Guy

Checking Out the Rheem Water Heater Web Site

Rheem Water Heaters

The first thing I noticed is that Rheem is number 1 on Google when you search for “water heaters”. They must be doing something right.

After looking over all of these hot water heater sites, they are getting pretty boring. However, Rheem does have a nice looking site and easy to navigate. There are some interesting things that I haven’t noticed at the other sites though. For instance, Rheem makes heat pump water heaters! Don’t run across them very often!

Heat Pump Water Heaters

Heat pump water heaters work just like your air conditioner, taking heat from the air around the heat pump and putting into the water. Since the heat pump is just moving heat energy from one place to another, it consumes much less energy than just heating the water up.

The warmer the ambient air temperature the more efficient they are, but if the ambient air temperature drops to around 40 degrees there just isn’t enough heat in the air for the heat pump to work effectively.

An energy factor of .9 is considered pretty good, where as the Rheem heat pump water heater has an energy factor of 2.0!

Solar water heating

Rheem seems to have a little of everything. They have several models of solar water heaters, both passive and active designs. They have all the specs and details you would ever want to know as well. And as you could assume, they have backup solar storage tanks with heating elements.

The Marathon water heater is interesting.

It’s a non-metal electric water heater. It has a plastic tank wrapped in fiberglass and other stuff. No metal to rust, and what they call a lifetime tank warranty.

It has two and a half inches of insulation which allows only 5º F heat loss in 24-hours! Other advantages include not needing an anode rod, so you don’t need to worry about smelly hot water. That rotten egg odor will not infect this tank.

It comes with a factory installed T&P (temperature & pressure relief) safety
valve and 4 feet of pipe insulation.


Tankless Water Heaters

Rheem also has a line of tankless water heaters. Typical sizes and energy factors comparable with the rest of the industry.

I did see a few features I wasn’t familiar with and have not seen with other models or brands, but then they might exist and I just haven’t run across them before.

They say they have a special cable to link two units together to operate as one for when you have for instance, really cold incoming water etc. The other related item is the ability to link up to 20 heaters using an optional manifold control assembly.

Probably wouldn’t need to do anything like that in a residential setting. LOL

Well that’s about all I’ve got for Rheem water heaters and the Rheem web site.

Later… Bill the Hot Water Guy

Bradford White Water Heaters and Web Site

Bradford White Water Heaters.

The next site I visited was the Bradford White water heater site. As with most of the other sites I’ve visited there are a zillion models of water heaters. The site seems easy to navigate and I had no trouble finding the residential products.

If you want to compare water heaters they have a great chart showing the energy factor for all their products including tankless water heaters. The chart makes it very easy to compare the energy efficiency of the various models.

I checked out the service manual for the Bradford White EverHot® Interior Tankless Gas Water Heater Models: IGI-180R-10(N,X) and IGI-180C-5(N,X) Manual 45095A

I must say they have a very extensive service manual. It does a very nice job of explaining how the models work. The theory of operation is very well explained and there are lots of timing diagrams, wiring diagrams, and illustrations. Reading through the service manual is like taking a course in tankless water heaters.

These heaters modulate the gas valve, the number of burners, and the water flow rate to obtain a stable output temperature even with changes in pressure from other appliances or faucets being turned on or off. It’s a technological marvel.

The tankless water heater trouble shooting section is even more impressive. Again, there are no shortage of diagrams illustrations and pictures to guide you. It’s extremely thorough and includes electrical trouble shooting and gas trouble shooting and anything else that can go wrong.

The only thing I found about maintenance was that sometimes you might have to use vinegar to flush the lime buildup out of the heat exchanger. Apparently the heater displays a message when it needs to be done.

Overall I liked the Bradford white site. I found it easy to use and full of useful information in a form that was easy to understand.

That’s if for Bradford White.

Bill the Hot Water Guy

A Visit to the Bosch Tankless Water Heater Web Site

At first glance the Bosch water heater site looks intimidating, but it only took me one click to find what I was looking for. On the left navigation column at the top under the heading “Consumer Information” I clicked on the link “Gas Products” and landed on a page with brief descriptions of the various gas water heater products that Bosch manufactures.

One thing I noticed right off is I don’t have to deal with PDF files! The Bosch web site quickly sends me to the page when I click on a link, and I usually find what I am looking for. Very nice.

The Model 2700ES Gas Tankless Water Heater was the first on the list, and so I clicked on the link to check out this model. The first thing I noticed was the statement that this model would supply 2-3 showers simultaneously! Wow!

I was certainly impressed. I immediately went to check the specs. Skimming the hype at the top of the page I noticed they claim a 20 year average life for the heater. I wonder if there is any evidence to back this up. Of course that doesn’t mean it did not need servicing or repairs during the 20 years, so it is of limited value at least to me.

The next section down the page is a large bulleted list of features, the first stating the water heater has an output of 7 gallons per minute! Enough for two good showers at once anyway… I don’t know about 3 though.

Now I am intrigued so I scrolled down to the technical stuff and discovered that it puts out 7.2 gallons per minute at a 45 degree F temperature rise. How disappointing! I mean it puts out plenty of hot water, certainly competitive with all the other brands, but I think the advertising is miss-leading.

After a more thorough look at the features and specs, I have to conclude that there isn’t anything very special about this gas tankless water heater.

I returned to the gas tankless water heater section and scanned down the products, and saw something that caught my eye. What I read was “The Bosch AquaStar Model 1600H incorporates a revolutionary hydro-generated ignition system, allowing the water heater to operate without a standing pilot, electricity, or a battery.”

So off I go to check it out. The features and specs page did little to enlighten me about how it works, all it said was no electricity needed, it generates it’s own. I wanted to know more about it so I went looking for some manuals.

On the manuals download page I was finally confronted with those dreaded PDF files. I first check the literature drop down box and downloaded the spec sheet. Nothing new there. Next I tried the Bosch Installation Manuals drop down box and selected the English version of the manual for the Model 1600H tankless water heater. They have the manuals in a number of different languages.

While reading the manual for the model 1600H water heater I made some interesting discoveries. How about the fact that there is periodic maintenance that needs to be performed on the heater.

Here is an excerpt from the manual:

“The GWH 1600 H requires periodic maintenance. The
below time maintenance intervals should keep the unit
operating for many years.

Every year
Inspect inlet water filter screen ( 5.2)
Inspect pilot assembly and flame ( 5.3)
Inspect burner assembly ( 5.4)
Every 2 years
Lubricate and clean water valve ( 5.2)
Every 3 to 5 years
Rebuild water valve ( 5.2)
Clean pilot assembly and clean or replace orifice”

The manual also states” Warning: Failure to perform recommended maintenance may result in complete failure of the unit over time. The warranty does not cover failures
due to improper or insufficient maintenance.

So maybe the maintenance should be done. The problem as I see it is that most people would not really want to do even the simple yearly stuff let alone rebuilding a water valve, or replacing a pilot assembly orifice.

I did find a drawing of the generator that provides the electricity to run the unit. No real useful information about it though.

I checked out the electric water heaters section and nothing new or different there. Electric tankless water heaters are pretty limited in usefulness due to the huge amount of electricity they require. Bosch doesn’t make standard tank type heaters, and only two models of tankless heaters.

They do have a couple of what they call point-of-use electric water heaters that have 5 or 6 gallon storage tanks, use 110 Volts, and produce about 6 gallons of hot water an hour.

Well I think that's about it for the Bosch Site.

Bill the Hot Water Guy