Home improvements - tankless hot water heater project

Its still the WEEKEND! And what do manly morons and adventurous wimmens do on weekends if they're not being couch potatoes or out shopping for shoes? They're hacking their their cribs, that's what they're doing.

When I fired the gas company last spring, due to their exorbitant "customer charge" just to read the meter and send the bill, and told them to come and get their meter, that committed ME to a couple of projects, one of which is finally complete. The hot water heater in this crib was gas, so I was going to have to switch to an electric unit. An ordinary electric unit would have proven uneconomical and I'd have been better off keeping the thieving gas company.

However, a tankless electric unit runs only when there's a demand for hot water, so its remains off and isn't maintaining a 30/40 gallon tank of hot water. I did the math and the payback period on this unit is going be about three years even considering slightly higher electric costs...but I'm already paying FPL their "customer charge" to read the meter and send me the bill, so I've eliminated the gas company's customer charge of $11.50/mo. I'll never use that much added electricity, so that's where the net win comes from, and during the summer months here in south Florida, you really don't need a hot water heater at all -- double win during the summer.

BTW, the little pic is clickable for a bigger image of what I did.

Up front, I'll state I went a little lot overboard with the plumbing and electric for this project. A tankless heater could be put in without needing its own electric panel or the elaborate 3-valve shutoff/bypass scheme I built.

The enhanced valve scheme is useful though. For one thing, I used ball valves rather than dribble prone gate valves that make soldering a nightmare. If this new heater fails, I'll be able to flip the valves on the hot and cold lines and get the whole thing swapped out in an hour or so. I had to shut off the main house valve to do this project because the single cold feed valve on the old crap leaked. You can't solder a pipe when there's water dribbling through it, it won't get hot.

Notice the bypass valve in the middle. This allows me to turn off the hot/cold lines to the heater, open the bypass, and shutdown/bypass the heater completely during the summer months.

There's a 90 amp feeder coming into the panel that serves the heater. The heater called for two 2-pole 40A breakers. I could have omitted the panel and did it quick with a couple of pieces of 8-2 Romex and been done, but that's not the way I roll, so I piped the whole thing in EMT, added a light switch and receptacles on the bottom, and flex conduit up to the heater. Some guys are proud of their cars or lawn, I'm proud of my electrical work ;->

In these days of funemployment, where leisure time is maximized, and the idea of paying plumbers and electricians maybe $2000 to do all this anathema, I think I got "out the door" on this for under $600. The heater unit was a Bosch factory refurb for under $300 shipped, that came with the same warranty as new. The panel and 3/4" EMT conduit/fitting/receptacles/switch/GFCI breaker I already had in stock. I had to buy the 1 1/4" EMT and fittings, I had the 1" flex conduit in stock. I had to buy all the plumbing fittings/pipe.

The going rate locally on a straight up tanked water heater swap from the plumbing companies is in the $600-$700 range...and that's not going to get you the 3-valve bypass mechanism or electrical. That just to swap what you got for the same shit.

posted by Purp at 01:08 PM

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