Install a water heater - plumbing.straw.waterheater PEP BB

I usually do stuff around the house/property and only after the fact think "I wonder if there is a PEP badge for this?"

Anyway, this is my first attempt at documenting something for points so if I'm doing this wrong, let me know.

I came across a deal on a small instant hot water heater that someone bought, looked at the scope of the project, and for whatever reason chickened out.  And no wonder!  Despite their look these things aren't plug-in appliances require some pretty serious power.  This one requires a 240v (aka two-phase) electricity on a 60 amp circuit!  And it's considered a small one... barely able to handle 1 shower at a time!

Anyway, the price was right and the wh that came with our house was getting a liitle old.  Indeed, if it wasn't so packed with sediment, I'm pretty sure it would have rusted through by now.

The installation steps were as follows (see photos below)

1) Finding a spot accessible to both plumbing and power.

2) Running cable and install a board to mount the unit to.  This used some pretty beefy 6-gauge cable, which is quite a beast to wrestle, and also (as I found out the hard way) takes HomeDepot a week to get in. :/

3) After running the cable, I installed new breakers.  Remember, this is two-phase, so it's a double breaker.  Fortunately in my case the blower for the old water heater happened to be right next to an empty slot so I didn't have to re-route anything. :)

4) Hook up the plumbing.  Unfortunately the model I got (ECOSmart ECO-11) used "compression fitting" threads, which are somewhat rare.  To make the adapter I needed I had to solder a compresson fitting nut to a 3/4 pipe adapter and jam an o-ring down in there for a seal.  And, yes, that arrangement took a fair amount of head-scratching and very wet trial and error to come up with.  (If you have the same connundrum and my description is unclear, message me and I'll get you more details)

5) After purging the air lines of bubbles as per the instructions, I powered on and everything works!  Hurray!  Now the only problem is staying in the shower too long because there is no such thing as "running out" anymore.

FUTURE NOTE:  I do still need to add an anti-scale filter inline with this.  Apparently mineral build-up can really kill the efficiency of these things.

LAZINESS NOTE:  For now I left the old water heater in place as I don't have a plug to cap off the gas line.  I could drag it out, but DW had the idea to use it as a reserve water storage tank.  Hmm...  What do you all think about that idea?

HUMOROUS NOTE:  So, I wanted to drain the old water heater, but when I hooked up a hose and opened the drainage valve, only a dribble came out.
"Aha!" I thought, "There must be so much sediment in the bottom that it's clogging the drain"
So taking a mighty breath like the big bad wolf about to blow a little pig's house down, I blew into the end of the hose.
"Yep.  That was it aright." I thought a second later, with water running down my shirt and a mouth full of black mud.
Cough, cough, spit, spit.
LOL! :D

I converted a school bus into and tiny home and installed a 7-gallon electric hot water heater for the sink and shower. It was pretty easy except for the tight space to work in and one sad night of water spraying everywhere from a loose fitting. But, now we have an instant supply of hot water and it's been working great for 6 months, no leaks!

I put a water heater I'm a new place in my basement.  

Here's a couple pics of the completed wiring

[Update note: Mike Haasl kindly pointed out that I didn't have a "before" photo, and like a dolt, I didn't ever take pics of my back porch as I was building it. SO, my "Before" shot is fig. 11, from when the house was delivered, showing yea verily no solar water heater (or porch). I think I mentioned in the post that I did this in stages, and mechanical assembly happened a bit before the plumbing/electrical hookup. It sits on S5! anchors, screwed through the roof/deck and into cross-blocking under each of the 4 feet.]

Hello, PEP-folks,
This is a project that I and my family finished over the weekend (but I bought the unit maybe 2 years back... sigh). I will describe both the mechanism of operation and the installation, and include photos. I am not a slick host-them-on-another-site-and-write-HTML type, so they may be in an undifferentiated mass at the bottom. Oh well.

The Duda Diesel company provides many wonderful things, including their open-loop solar water heaters. The closed-loop siblings of these are ideal in a cold climate, but I live in central AZ, and freezing is not an issue. The model I installed was the SUS304 150L (~40gal) stainless steel exterior one. I liked the shiny-ness.

These are billed as a triple-reflector vacuum tube (fig. 1). Imagine, if you will, a test tube nested inside of and sealed at the open end to another test tube, both ends pointed down. The inner tube is metallized on both sides, with the outer layer having a solar-absorptive coating, and the inner layer being apparently copper (fig. 2). There is an open-to-air well down the length of the tube (fig. 2 shows the open end). In this well sits a bent sheet aluminum reflector (looks vaguely like the Bat-symbol), inside which nestles the ultimate target, a copper heat pipe.

Depending on the position of the incoming ray of light striking the outer tube, it might HIT or MISS the inner tube. If it MISSES the inner tube, the back reflection from the inside of the outer tube back wall is the first bounce, and the ray will be directed into the back of the inner tube. If the ray HITS the inner tube, pretty much anywhere, the metallization on the INSIDE of the INNER tube will bounce the ray into the sheet aluminum reflector, thence to the heat pipe. Basically, within three bounces at most, a ray which strikes the outer tube at any angle will end up depositing most of its energy into the heat pipe, and a key function of the outer tube is to stop convective heat loss from the tubes. Noon is better than sunrise/sunset, but mostly because of the cosine term associated with the whole collector area. Fig. 3 jumps the queue a little bit, but shows the tube array to help illustrate what we are talking about.

The heat pipe at the center of the tube is about 6ft long. I am still taller, but it makes me feel rivaled. It is a partially evacuated tube with a phase change material (not sure what this one uses, ammonia or water are common). The condensation happens AT THE TOP inside the water tank. The hot water is cooling the hotter fluid. Then the fluid by condensing it. Then the liquid dribbles or wicks back down the tube, and is re-evaporated against the hot-hot walls that are lit by the sun. Vapor flows up the hollow core of the tube to condense at the top. They are nifty, they are in use all over the space station, and they like a well-defined slope (they don't work inverted, generally, except the NASA ones that don't care about gravity anymore). This carries the heat from the sunlight up into the water. I do not know the details of the receiver at the top, where there is a brass well in the water tank which receives the condenser bulb at top of the heat pipe, and if you zoom in on fig. 4 you might see it in the last socket.

The water heater is an insulated horizontal  tank with an aluminum-zinc anode rod (like 12in long, 3/4in dia, biggie), a backup electric element, and a thermowell where the RTD sits to measure the water temperature. It has a T&P relief valve up top, and a nicely color-coded cold-in and hot-out line. All lines are 3/4NPT - bless their souls. It sits on a frame which gives a decidedly underbuilt impression, but it seems to work, and has cross-bracing, so it ends up stiff. I installed the frame a while back, before getting up gumption to cut holes in my porch roof. See fig. 5.

Piping cut-in was at the feed to the interior water heater, which I left in place and operational, no change to the setpoint, but with only a single 2kW element rather than both. We are fully off-grid, and the 4kW hit of a water heater turning on in the early AM can dip your voltage below cutout sometimes. More on the solar system in future posts. Fig. 6 shows the bypass installed, it is possible to isolate the roof from the utility closet and leave the flow only going through the indoor heater. I have since applied pipe insulation to the hot side of this loop. You will see that it is PEX-B, which is the Home Depot kind, and came with the house. I am a PEX (crosslinked polyethylene) aficionado, and install PEX-A (Uponor, the original from Canada) wherever I can, but the pipe type you have is the pipe type you use. I did transition to copper (after 6ft of PEX-B on each line) for the run out of the house and up to the roof, as seen in fig.s 7-8 (again, some photos prior to full pipe insulation).

A drain hosebibb was left below the tank on the roof, to empty an isolated tank if required. Unions are installed below each threaded tank connection for service. Lead-free brass is used throughout for valves, NSF61 compliant. All threaded plumbing seals use the Tru-Blu goo from Home Depot, which I have consistently had success with in a variety of installations for water. (I do not like teflon tape for outdoor connections, or even really on hot water lines. It is too active and slippy, in my opinion. Your mileage may vary, not trying to start a fight about pipe tape... we're all blocking the same spiral leak path here...)

I added a 20A 120V circuit to feed the controller, fig.s 9-10. The controller receives signal from the RTD in the tank, and controls the supplemental heater. That heater is there to keep the temperature above legionella-land. However, so far, the temperature in the tank has daily reached self-sterilization temperatures >165F, so I have not programmed the heater yet. Probably will for winter. The manual is, er, poorly grammatical. Maybe by winter I will have figured out the programming screens. Recall that this is upstream of the still-operating conventional heater, too. The lowest we have seen the water temperature is 115F in the early morning.

I mentioned that we were off-grid. This device made an immediate positive impact on our power balance, since we are running the main water heater way less than before. It means that hot baths for kids at night are not a power nightmare (they have appreciated).

And yeah, about figs 1 & 2. Those tubes sure are broken. I thought ahead and bought the extra 6-pack of glass tubes thinking to have spares for years to come. Well, while they were in boxes on their pallet, my kids climbed on them and jumped off. Crunch. Exactly six tubes broke (between all 3 boxes). So I have a complete system, but no spares, but I will count my blessings. They're good farm/ranch kids, their instinct is "let's climb it and jump off", and I wouldn't ask for anything else except maybe better comprehension of warning symbols on boxes. They'll get there, too.

Happy homesteading, comments and feedback welcome!
Mark