Tankless water heater annual maintenance - flushing with vinegar!

Back in 2010, our propane fired water heater tank sprang a leak and I took this as an opportunity to install a tankless on-demand water heater (detailed blog).  These heaters are much more efficient because there is no heat loss from a large tank.  When the hot water faucet is opened, the heater kicks on and fires up a propane flame to heat water passing through the heat exchanger.  The moment the hot water faucet is shut off the heater shuts down. 

Like all equipment, this device does require minimal preventive maintenance.  Most people never think to do maintenance on their water heaters but doing so can dramatically extend their life and replacing a water heater is always an expensive proposition.  Recently I blogged about replacing the anode rod in my solar storage tank which is actually an electric water heater that is disconnected electrically.  This has the potential to more than double the working life of that tank by preventing the walls of the tank from rusting through.

Maintenance for a tankless heater is a little different.  You need to take a gallon or so of virgin food grade white vinegar, and pump it through the heat exchanger to dissolve scale build up inside of it.  (Rinnai recommends using 4 gallons of vinegar but I think this is more than is necessary).  While the warranty from my heater is 12 years for the heat exchanger and five years for parts, I believe firmly in doing routine maintenance like this on an annual basis.  My Rinnai heater has valves and hose connections to simplify the process of flushing heat exchanger.

Here are the valves with the fill/drain caps removed:

The flushing procedure involves putting vinegar in a 5 gallon bucket and using a small electric pump to pump water from the bucket through the heat exchanger and back down into the bucket.   I already had a pump and several short lengths of clear garden hose that I use to drain and fill my solar heating systems annually.  I made up the hoses by purchasing clear plastic hose and adding standard hose male and female connectors to the ends so that I can see the fluid moving through them.

Here I have connected the hoses and reversed all of the valves to isolate the heater from the building water supply and switch everything over so that the vinegar passes directly through the heat exchanger and does not enter the building's plumbing:

The image below shows the complete set up:

I wired a foot switch to the pump so that I can start and stop it quickly as needed.  After running the pump for several minutes the water turned slightly turquoise which is the color of the copper plumbing oxide.  This confirms that I am removing scale build up inside the heat exchanger.

Here's a picture showing two bottles of vinegar, the one on the right contains the vinegar I used for the flushing process so you can clearly see the change in color:

By the way, the other use I have for white vinegar is as a natural weed killer.  I use a small spray bottle of 100% vinegar and spray it onto broad leaved weeds in the middle of a sunny dry day.   When the plants are thirsty they try to ingest the vinegar and it kills them quite effectively. I plan to reuse the flushed vinegar as weedkiller which is why I saved it back in the original bottle.

I am aware that I make this procedure seemed rather simple, but it does involve some experience and special equipment.  So if you are not DIY inclined, and you have a tankless water heater, you may wish to hire a plumber every year to perform the flushing procedure to ensure your investment is protected.   Tankless water heaters are significantly more expensive than a tank style heater so there is real value in this relatively affordable maintenance.

From a sustainability standpoint, maintaining equipment like this extends its life - keeping it from the landfill.  When my heater eventually fails, I intend to responsibly recycle as much of it as possible.  The heat exchanger itself contains a significant amount of valuable copper which can be recycled for instance.

If you are looking to buy a tankless water heater, here's a good review of current models: https://www.reviews.com/tankless-water-heater/

My solar lawn mower - still going strong

UPDATE 2022 - I "retired" this mower and purchased a new Greenworks mower  performs really well!  Back when I built this mower, cordless electric ones were not available and now there are dozens of models.  I was able to sell the huge motor for $200 and recycled the lead-acid battery.

Over eight years ago years ago I was inspired by a small article in Home Power magazine in which a guy named Al Latham described how he had converted his standard 22 inch gas powered lawnmower to use an electric motor and battery that he charges from solar.   I decided to make my own conversion and have been using it consistently to cut tall grass and weeds in our so-called lawn ever since.

At this time of year I transition from charging the mower from a standard automobile battery charger to using a couple of small solar panels on the south facing roof of my storage shed.  These panels combine to a total of 40 W which is enough to charge the mower in one day of clear sunlight.  The 10 amp automotive charger can charge it up in a few hours.

Gauges on the handlebar show battery Voltage and Amps drawn when the motor is running.  As you can see it draws up to 30 A and can sustain this for 20 minutes or so which gives me enough time to mow a large section of our quarter acre lawn.  

In the middle of the summer 20 minutes is about as much as I can handle because this mower is quite heavy with the very large motor and lead acid battery and it becomes sweaty work.   Nonetheless, it is a delightful mower to use because it is very quiet and powerful enough to cut through tall weeds.

Maintenance involves sharpening the blade every year and replacing the battery every 2 to 3 years at a cost of $60-$80.   So this is definitely more expensive to operate than a gasoline lawnmower, but it has zero emissions and may last significantly longer than one of its gas cousins.

If you want to learn more about the construction of my solar mower, I have a detailed blog on my website with clear instructions on how to build your own.

Firewood: it warms you twice

wood pile and my workshop building

It is early May and spring is finally here in Maine and we are getting some warm days with temperatures peaking as high as 80°F already.  I spend much of the day in my home office sitting in front of a computer or my electronics workbench where I design and develop electronic products so my days are relatively sedentary and I look forward to outdoor activities at this time of year where I can use my big muscles. 

Each year I set a goal of cutting 1 cord of firewood from our 2 acre woodlot behind our house.  This is just enough to augment the solar/propane heating system for my super insulated workshop,and it is great exercise.  As they say; "Firewood warms you twice, first when you cut and split it, and then when you burn it".

woods behind our house in Maine

The woods behind our house are relatively young - the land had been clear-cut 50 to 60 years ago so we have a lot of small young trees competing for the canopy.  Many of them do not make it and I find them dead or dying.  My strategy for responsible forestry management is to start by harvesting these dead trees or blow downs from the winter storms first.  Very often I will find trees that have been dead for a while and are already debarked and quite dry.  I place this on my pile closest to my workshop door because it will be the driest wood.  Ideally, wood cut from living trees needs to season for a minimum of 6 to 9 months, so my next step is to seek out trees that are crowding each other out and cull them to allow nearby trees to grow to maturity.  

As a sustainable guy, I cannot countenance using smelly fossil fuel powered chainsaws so I have two electric chainsaws.  One is a 14" lithium battery powered cordless saw made by Oregon:

Oregon CS250 cordless chainsaw

I use this to fell and de-branch trees back in the woods and then cut them into lengths that I can carry to my cutting station.  I am extremely pleased with this chainsaw, it cuts really briskly and the battery lasts for 20 minutes or so which is plenty of time to fell several small to medium-sized trees and cut them up.  By the time the battery needs recharging, I am usually ready for a break and charging takes about an hour or so.  It also has an unique feature in that it has a built in sharpener.  Best of all, it is relatively quiet and there is no stench of gasoline fumes.  It is also completely carbon neutral since the power for the both chainsaws comes entirely from our solar array.

I also have a Poulan 3.5 hp electric chainsaw that I run on a long extension cord:

Poulan PLN3516F 3.5 hp chainsaw

This is the saw that I use at my cutting station to buck the logs to 16 inch lengths:

bucking logs in to 16 inch lengths
photo: Rebekah Younger

Finally, I split the larger logs:

splitting a log 
photo: Rebekah Younger

I have spent about three afternoons so far and have prepared about a half cord of wood:

about 1/2 cord cut and stacked

For the uninitiated, a cord measures 4 ft. X 4 ft. X 8 ft. and has a volume of 128 cubic feet. The amount of solid wood in a cord varies depending on the size of the pieces, but for firewood it averages about 85 cubic feet.  Firewood needs to be stacked and left to dry, so I cover the top with a tarp to keep the rain off but leave the sides open until the winter.   Before the first snow I typically cover the entire wood pile with a large tarp.   Last winter we had over 3 feet of snow on the ground and it is important to keep the snow off and the wood dry.

Fortunately, the weather on the days I have been working has been pleasant and in the 60s.  As the weather gets warmer it becomes less enjoyable to work, so I try to get as much cut as I can before the warm weather.  When the heating season starts in late September, I enjoy reminiscing about the specific trees that I cut and split as I put them in the wood stove.  There is also a layer of satisfaction of knowing that I harvested all of the wood myself.  For the house where we use 2 to 3 cords of wood a year, I capitulate and purchase pre-cut firewood that we have delivered.  There is still some sweat equity involved in stacking this wood though! 

From a sustainability standpoint modest use of responsibly harvested firewood is essentially carbon neutral since I am simply shortening the carbon cycle of trees that would naturally fall and decay thus releasing their carbon.  By giving precedence to dead or dying trees, I'm reducing my impact on the natural cycle.

Replacing the anode rod in my hot water tank to extend its life

Every three to six months I connect a hose to the bottom of my water heater and drain a few gallons into a white bucket to remove gunk and the debris that comes off the sacrificial anode rod as it slowly dissolves. The purpose of this anode rod is that it dissolves through a process of electrolysis, and by doing so prevents the walls of the tank from rusting out.  Today, I decided to replace this anode rod, because when I drained water earlier I was seeing rust in the water which is a danger sign that the walls of the tank may be rusting out.  Here is a picture showing how it is installed in a standard electric water heater tank:

It is clearly visible at the top of the water heater tank as the only large nut on the top. 
 

Below is a picture of a brand-new rod, and below it what was left of the one that I replaced:

New anode rod

worn out anode rod

Clearly it had done its job, and I am concerned that the walls of my tank may have begun to rust.  I had to borrow a neighbors half inch ratchet wrench, and purchase a 1 1/8 inch socket.  He helped me by bracing the tank while I used the ratchet wrench with a six-foot pipe extension to break loose the old rod.  Fortunately the whole replacement process went fairly easily, all we had to do was shut off the water pressure and drain a little water out of the tank by opening the drain and the P/T valve at the top to allow air to enter before removing and replacing the rod.

This water tank has been in service for six years as my solar hot water storage tank, and another six years prior to that it was my primary source of hot water.  This should serve as a cautionary tale to anyone with a water heater tank.  It is a lot less expensive to replace the anode rod than it is the entire water heater!

Note: due to the low ceiling height clearance, I installed a flexible rod like the one below.  

Generally they are straight and measure 24″ to 36″ long, and some are even longer.  Your anode rod needs to be sized to match your tank.  Here's a link to the one I bought.  (as an Amazon Affiliate, I earn from qualifying purchases.)

This is part of my ongoing series that deals with the concept of repairing rather than replacing as a way of living sustainably.  One can argue that living sustainably can save you a great deal of money over the long term, and this has certainly been true for my lifestyle.

 NOTE: The tank finally sprang a leak on July 18, 2015 and I replaced it. More about that here.

Understanding solar insolation

Having solar power systems on one's home means that you become very conscious of the daily and seasonal cycles of the sun.  The word insolation is used to define the total amount of solar radiation energy received on a given surface area during a given time.  It is insolation that is used to calculate how much energy you can get from solar panels or collectors for any given location and time.

If you live on the equator you do not see significant seasonal variations in insolation, but where I live at 44° latitude, it varies considerably throughout the year and it is important to understand this in order to correctly predict how much energy one can extract from the sun.

There is a very helpful web calculator produced by PVeducation.org that produces charts of available solar energy (insolation) for given locations.  I use this tool to create the animation below that shows the available solar energy in Watts/square meter in 10 day increments for the year at my location of 44° latitude North.

I made this animation by taking screenshots at ten-day intervals by adjusting the slider on the calculators webpage.

This clearly demonstrates how the available sun hours per day varies significantly at my latitude.  The chart below shows the predicted versus actual solar energy produced by my solar array and clearly shows the seasonal variations.  The predicted energy was charted using the calculator from National Renewable  Energy Labs called PVwatts which takes into account both seasonal variations and local weather conditions.  The actual data came from monthly energy production reports from my solar array. 

 

Over the years I have added panels to my solar power system which accounts for the annual increase in output.  If you are considering installing solar power or heating systems on your home it is important to be aware of the seasonal variations and the impact of local weather. 

Repairing - not replacing our microwave oven

Our microwave oven stopped working a few days ago - it made a loud humming sound and produced no heat and smelled a little smoky.   I took this as an opportunity to blog about repairing versus replacing.   This is a recent model Sears Kenmore microwave oven that was only about four years old and sending it to the landfill is just not something I am willing to do.  So I did a web search on the model number and found a number of suppliers that sell spare parts.  I am familiar enough with microwave ovens to know that the most likely component to fail is the cavity magnetron.  This is the large expensive device inside that converts electricity to microwave energy.  (And no, it is not "radioactive"!   Microwave energy is in the radio frequency part of the spectrum).  I found a supplier that listed a replacement part for about $65 plus shipping and it arrived in the mail this morning.

Microwave oven with replacement magnetron

Most home appliance repairs can be accomplished with little more than a screwdriver, and the only challenge in repairing this microwave oven was that the screws on the back required security bits to prevent ill-informed people from opening up the device.   Fortunately, I already had a security bit set with almost every known type of security screw bit.  Sets like this can be purchased for around $10 in a good hardware store.

security bit set

After unplugging it, it was a simple matter to remove the half-dozen screws on the back, and then I found a couple of simple Phillips head screws on the sides.  Manufacturers are tricky and will often mix and match screw types and even hide screws underneath paper or plastic labels to prevent you from figuring out how to open up their products.  It is also important to document everything as you remove parts so that you can remember how to put them back together again.  This is where a smartphone comes in very handy, or any digital camera for that matter.  Also be careful never to force anything when you are taking it apart.  If something does not come loose easily, it is probably due to a hidden screw or fastener.  Slow down and look very carefully for well hidden screws or catches.  When products are manufactured the components are designed to assemble quickly and easily and so dis-assembly should require very little force.

Having removed the cover, it was easy to identify the magnetron inside:

microwave oven inside with replacement magnetron

The magnetron itself was secured with standard Phillips head screws:

magnetron secured with Phillips head screws

After I unplugged the electrical connection, I removed the magnetron and installed the replacement, and buttoned everything up again.  A quick test of the microwave oven with a cup of water proved that it was working perfectly and actually sounds quieter now.  This whole process took less than 30 minutes and anyone with the desire to do it can do this themselves.  

In our disposable economy I realize that I am somewhat heretical in that I firmly believe things should be repaired and not replaced without a thought.  I hope that anyone reading this will consider repairing a broken appliance themselves.  Not only is it very satisfying to repair something, but it also saved over $100 on the replacement cost of a new microwave oven.

If you are on a tight budget and happen to see an appliance that someone has put out with their garbage, you might want to consider it an opportunity to acquire an affordable appliance with a little repair work.  If you are even more enterprising, you could do the repair and then donate the appliance to a worthy cause!  All of this is something to consider in the spirit of keeping things out of the landfill.

Interior storm windows - thermal study

In an earlier blog post I talked about the benefits of installing interior storm windows to reduce heating bills in cold climates.   You can purchase these double pane plastic film windows for about nine dollars per square foot, or you can make them yourself for around $1.25 per square foot.   Instructions to build them yourself or on my website.   They consist of a wood or metal frame with heat shrink clear plastic on both sides creating a trapped air layer in between.  They fit snugly into the window with highly compressible weatherstripping that prevents air movement through a leaky window.

I have installed these interior storms throughout my workshop because the original windows were cheap, single pane, double hung units that are very leaky.   When I first closed in the building from being an open barn to a heated space I purchased commercial interior storms, and more recently have added my own handmade ones as well.  For every trapped layer of air, an R-value of one is added.  So starting with a single pane of glass, by adding a double pane interior storm there are two trapped air layers creating and R-value of two, and by adding a second interior storm I am upgrading my original windows by an R-value of 4 which is very significant.

Fluke VT04 Visual IR Thermometer

This evening I decided to document the thermal efficacy of these window treatments using my VT04 Visual IR Thermometer made by Fluke.  The temperature outside was almost exactly at freezing and I started by taking a picture of the window with a temperature reading of the glass surface at 31.7°F:

Then I proceeded to take thermal images of the window itself, followed by each of the additional interior storm windows:

By adding my homemade interior storm window I gained 3.6°F and then adding the commercial aluminum framed interior storm window I gained an additional 1.8°F for a total improvement of 5.4°F.  While I adjusted my thermal camera to compensate for the low emissivity of the reflective surfaces, I cannot be sure these readings are entirely accurate, but they certainly convey the concept.

My homemade window is framed with 1X2" primed pine lumber with 3/4" spacing between the panes, while the commercial one is framed in aluminum with only 1/4" between the panes.  Additionally, the air gap between the glass and my window is between one and 2 inches, while the air gap between my window and the commercial one mounted to the surface of the window framing is around 4 inches.  Larger air gaps are less efficient because they can function as a heat pump as cold air flows down at the colder surface and warm air flows up the warm surface creating a circulation.

 

Solar collectors and panels explained

I am often surprised when I come across people who are unaware of the difference between a solar panel a.k.a. PV (photovoltaic) panel and a solar collector.  Both types are seen installed on sloping roofs that face south.  (They are never seen on north facing roofs in the northern hemisphere, so if you are lost and see them on a roof you can generally assume they are facing south). So for those who do not know the difference, here is a simple clarification.

A solar collector is a device that absorbs heat from the sun which is then used directly or stored in a tank inside the home.  Collectors can be used for both building heating and domestic hot water heating.   Here is a very basic diagram showing how it works.

The principle is similar to leaving a garden hose out on your lawn on a sunny day - the water will come out warm.  Collectors are much more efficient and sophisticated version of this.

There are essentially two types of collectors.   Flat plate collectors are often confused for solar panels because they are large rectangular devices with glazing on the front.  Inside there are sheets of black metal heat absorber material coupled to copper plumbing.

The other type of collector is an evacuated tube collector like this:

These collectors have a heat absorber pipe inside something that is similar to a glass thermos bottle.  Heat is transferred to the plumbing manifold header at the top.  The vacuum glass tube prevents heat loss and improves efficiency.

On my property I use flat plate collectors on my house to heat water, and on my workshop building to heat the building via radiant floor and radiators.   Both systems also use small solar panels to provide electricity for the circulation pumps that pump the antifreeze fluid through the collector to the storage tank.  Due to the lower cost compared to solar electric panels, both of these systems generally have had a much shorter return on investment than solar electric systems.

How I eliminated junk mail

Several years ago, I decided to tackle my junk mail issue. My mailbox was filled with catalogs and other junk mail every day and I realize this amounted to an enormous amount of waste despite the fact that I recycled everything.   The idea of cutting down trees, printing catalogs and mailing them to a recipient who immediately disposes of them is the epitome of an unsustainable reality and I wanted no part of it.

I took several approaches to eliminating junk mail.   First, I subscribed to the TrustedID - one of several direct mail preference services and entered my preferences on their website.  This organization effectively handles the rest for you, here is what they say on their webpage:
We act on your behalf to protect your consumer rights and get your opt-outs processed. You can keep track of your opt-outs, and if you receive the mail again, we will follow up. We work with over 8,000 companies — and the largest data brokers — to honor your choices and protect your privacy. We have processed over 25 million opt-outs by over 1.7 million account holders. 

The direct mail industry also offers another option known as the National Do Not Mail List.  Both are good examples of an industry policing themselves in order to reduce their own costs.   Here is how they explain their service:
As direct marketers ourselves, we know that mail-order companies don't want to waste their money sending mail to people who don't want to receive it.

They'll gladly take your name off their lists when they're asked to do so. But with countless mail-order companies doing business today, you just can't contact enough of them on your own to make a difference. The postage alone would cost a fortune!

A similar option is available from DMAchoice.org  which also offers an option for reducing junk email.

Incidentally, if you have not already signed up with the National Do Not Call Registry - a service of the Federal Trade Commission, you can reduce the number of telemarketing phone calls that way.  I have signed up for that service, but still get solicitation phone calls.  The way to eliminate these is to refer to their caller ID and call them back, many of them offer an option of "press 1 to be removed from our calling list", and if not some of them will connect to an actual person who will remove you from their list if you ask nicely.  I feel that is important to be polite when asking to be removed - the person you are talking to is not the bad guy here, just an employee.

Finally, when all else fails I made a simple rubber stamp that prints the following:

please remove
from your mailing list
thanks

Of course you can also write this on their subscription form. This is particularly useful when they provide you with a postage free return envelope.  All I do is remove the return section, stamp it next to my address and stick it in their envelope.  They get the message eventually!

I also reduce mail in general by paying all my bills electronically either through direct debit or paying through the company's web portal. 

At this point I can honestly say that I rarely get any junk mail whatsoever.  I still do get a few catalogs and mailings from companies I do business with.

According to another junk mail reducing web site: www.41pounds.org: "The average adult receives 41 pounds of junk mail each year of which 44% goes to the landfill unopened" (or hopefully it is recycled).  They have more statistics that make the idea of reducing this waste very compelling.  They have a $35.00 one-time fee and use $10 to support effective non-profits like Habitat for Humanity.

If more of us took this simple action, we could have a significant impact.

On a slightly different topic, I have also subscribed to Incogni - a service that removes all of your personal information from the Internet.  From their website:
Data brokers collect your personal information and profit off it at the expense of your privacy. Let Incogni help you take back control of your data, reduce spam, and prevent scam attacks by opting you out of their databases automatically.
A one month or two months subscription should take care of everything, just be sure to cancel your subscription after two months.  After this it is largely unnecessary.

Conserving water with a circulation pump

Like many houses, our master bathroom is at the far end of the house from the water heater.  A total of about 45 feet of copper pipe that must be heated before hot water arrives at the faucet.  This takes from 80 seconds in the summer to over 2 minutes in the winter, and wastes a lot of water and energy used to heat it.  When I learned about a clever pump made by ACT, Inc., I decided to install it right away.

The principle is that a pump is installed under the sink that pulls hot water up to the pump, and returns it back down the cold water pipe to the water heater at the press of a button.  The 54 Watt pump shuts off as soon as sufficiently hot water is present.  Each time you need hot water you just press a button and wait half a minute while the water is sent back to the water heater tank instead of down the drain.  The pump shuts off at a pre-set temperature.

 

This system differs from other designs that constantly circulate hot water through the plumbing to keep it available at all the faucets constantly.  I don't  recommend that type of system as it actually wastes energy, both at the pump and due to radiated heat loss from the plumbing which acts as a defacto radiator in the walls of your house.
The D'Mand system reduces waste and saves energy in 3 ways:

• reduces the use of our 1500 Watt 240Volt  well pump.
• reduces the need to heat water that would just go to waste down the drain.
• reduces waste water entering our septic system.

The only drawback is that the pump requires electricity under the sink, which requires wiring in a new (GFCI protected) outlet in most cases.  The basic pump and controls sell for about $400, plus some plumbing parts.  So the installed parts cost was around $500.

The installation of the pump is quite simple.  After shutting off the water supply and draining the lines to the sink, the faucet shut offs are removed.  A tee is inserted, and the shut-off is replaced.  Then the 2 flexible lines to the pump are installed onto the new tee thread.  This took me about 20 minutes.

I am an experienced plumber so I had no trouble installing the pump.  Any plumber would also find this a simple installation.

The challenging part is that an electric outlet is required under the sink.  The nearest outlet in our bathroom is off to the right.  So I made a run to the hardware store to get a bunch of Wiremold (surface wiring conduit) parts.  Then I added a breakout box on top of the existing outlet and ran Wiremold channel across and down into the space under the sink where I installed a new outlet for the pump.  This part took over 3 hours!

 
I also made an attractive circular white acrylic switch plate, and used a stainless steel push button.

Once the button is pressed the pump turns on immediately and shuts off automatically as soon as it senses hot water at the pump.  This saves several gallons of water that would otherwise run down the drain, and reduces the usage of our tankless water heater.  In our home the cold line returns to the bottom our solar storage tank where the sun heats it up for free.

Before the pump was installed it would take 80 seconds for the hot water to arrive, now the pump brings it up in about 50 seconds after pressing the button, and the water runs hot from the faucet within a few seconds.  They also make a motion sensor that will turn the pump on automatically when you enter the bathroom (or kitchen).  Here is the accessories page.

This system is relatively expensive and I don't expect a payback any time soon.  This is something I did as part of my commitment to living sustainably using technology.  I admit it may not be for everyone.