On-demand hot water for shower

[Doug Coulter]

"Don't try this at home" - everyone told me it wouldn't work, would burn down the house, kill me with carbon monoxide. whiteboard wouldn't do as it'd rot or sag - even though it doesn't get wet.. Well, nope.

I got a small propane on-demand heater intended for camping (who the heck needs that - some new definition of camping?). Cheap stuff, but careful installation and don't twist off the connectors and it's good.
A friend, Jeremiah, came over and installed it with some whiteboard Bill had brought me. The quick coupling for the shower head was drippy at my line pressure, so I installed a ball valve, mostly because it was not dissimilar metal and was F-F npt - and a nipple and hose clamp instead of their arrangement - not one drip.

Side view. It's a tiny room so I couldn't get back far enough to get the whole thing in frame.

My mod to the hot water side.

The CO monitor (another donation from Bill) I put in the room didn't go off. Because "everyone knows" it's going to burn the house down - despite being an on the spot fire extinguisher...I used the thermal camera to take some pics after a good long wash. Heh. It's efficient, most of the energy goes into the water, as it should. Only the exhaust port gets actually hot.
Here's the thermal pix.

Ceiling above the unit

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And the unit. Of course, the clock in the camera is way off...as is the registration between the visible and IR. But it was cheap!

Only the exhaust port gets hot.

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Here's a link to the unit on Amaon.
The reviews about the crappy shower hose can be disregarded, they fixed it with a better one. But the quick coupler for the output leaks like a compressed air fitting (which it's a copy of).
Can't have that, so I added the ball valve and a real hose nipple and clamp.


So, after some years having to make sure I had surplus water, and surplus electricity, which rarely happen together...now I can wash my sorry butt pretty much anytime. This doesn't waste water or propane.

[johnf]

A big improvement

keep them coming

[Doug Coulter]

Well, with some parts from Amazon, and some help from Bill, this project seems pretty complete other than the usual workout of any bugs.
Got a seat, some handle/hangers etc installed.

Shower head hanger - I lost the original and it wasn't great anyway.

Grab bars, seat

We also fixed an issue with my auto-fill setup that transfers water from the rain barrel to the basement cistern and auto stops when it's full. I thought it was the valve, but nope, just a wire that corroded through somewhere I didn't notice it. Oh well, those aren't expensive valves and they are super good. And now I have a few spare ones. That's another thread, but this is all controlled by an esp8266 down there in the crawl space that also collects water level and in/out weather data for this building. A pi polls it once in awhile to get the data we plot from a mysql database on the pi. It's even got over the air updates...nice little sketch.

[Doug Coulter]

Just did a test shower to see how all this works in real life. It's very nice! It uses a lot less water than the old low flow setup did as well and not putting as much past the shower curtain onto the bathroom floor.
Just a lot more efficient, took a lot less to refill the cistern afterward.
And now I know where to put the second shower head/washcloth hanger, which was the point of the exercise as well as getting clean. I'll be able to shower a lot more often now, which is nice to say the least.