I just want to say thanks to Solid for helping me install a new water heater yesterday. He has a black belt in “house fu” and wields the tools of this ancient art like a seventh-kyu Okinawan “Master of the pipe”.

We finished around midnight last night (started late around 7-ish and had a 1.5 hour break for dinner at 9) and after about 20 minutes of waiting the water coming out of the hot tap was considerably warmer than the water coming out of the cold tap so we assumed success. Solid went home and I went to bed. Needless to say, I washed away any stress I had about the new water heater with my hot shower this morning.

My trials and tribulations of swapping out a propane water heater with an electric one can be found in the rest of this post (along with lots of statistical info, prices, and wisdom).

click the title to read the whole story
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Old Water Heater – Why We Needed a New One

We had a “made in 1992” A.O. Smith “Energy Saver” 30-gallon propane water heater. When it was new, it was probably about 70% efficient (a “blue light special” even at the time). Nowadays, not so much. My guesstimate is around 40% efficient (meaning that most of the heat generated by the propane went right up the vent). Essentially, the “pilot light” burned about as much as a back yard grill and when it kicked into “full money burn” mode, you could feel the oxygen in the house being sucked into the garage. It had an effect not so dissimilar to that of that vortex ball thing in The Arrival. At least it gave us hot water… For around $270/month ($3/gallon)!

New Water Heater – Propane?

I did a lot of research and figured out that the most efficient propane hot water heaters are the new tankless models. At around 87% efficiency, they looked like they could take a huge chunk out of my propane bill (no residual heat loss and infinite hot water). However, at $700 for a 4.2 gpm model (enough for ~2 simultaneous showers) I had to ask myself, “Is propane even worth it?”

A couple of things to note about propane tankless water heaters:

• They require a wider propane feed than would be typically required for a tank heater.
• They require a larger vent than would be typically required for a tank heater.
• They require an air intake vent (i.e. it will turn your garage into a vacuum).

• They generate loads of CO and CO2 which is bad news if something goes wrong.

  Considering that my existing vent was only 5 inches wide and my propane feed line was too small, I’d need to A) Install a new vent and widen the current hole, B) run a new propane line ($$$ from the gas company), and C) spend a fortune to have someone come out to do it since I don’t want to mess with propane lines. All this added to my skepticism of propane. Besides that, propane is made from oil and prices are only going to go up

  Propane VS Electric

  But how much does it cost to heat water with propane VS electric? In order to figure this out we need to know some things:

• How much does 1 kilowatt of electricity cost in your area?
• How much does 1 gallon of propane cost in your area?
• What is the incoming water temperature for your house?
• Conversion equations, BTUs, etc.

• Efficiency ratings on equipment.

  For me, electricity is $0.098/kilowatt, propane is about $3/gallon, and the incoming water temperature is 68 degrees (Jacksonville, Florida). With that in mind, here’s the other statistical information:

• Electricity = 3,412 BTUs per kilowatt
• Propane = 92,310 BTUs per gallon
• 1 BTU will heat 1 pound of water 1 degree F.
• 1 gallon of water = 8 pounds
• 8 BTUs required to heat 1 gallon of water 1 degree
• For example’s sake, we’ll assume a 87% efficiency propane water heater (highest they come).
• For electric, we can assume a 100% efficiency rating on the heating coils since there is no heat loss (and the figure is the same for all heating coils if they’re new/maintained).
• Target water temperature is 140 degrees.

• We’ll assume we’re heating 50 gallons of water (which is my target tank size—30 was too small).

  The beginning calculations (basic):

• 80,310 BTUs per gallon of propane at 87% efficiency.
• We need to heat the water 72 degrees (140 – 68).
• 28,800 BTUs are required to heat 50 gallons of water 72 degrees.
• 0.36 gallons of propane required to get a 50 gallon tank to 140 degrees (68 degrees in).
• 8.44 kilowatts of electricity required to get a 50 gallon tank to 140 degrees (68 degrees in).

• That’s $1.08 in propane, $0.83 in electricity.

  As you can see, heating your water with electricity is significantly cheaper. Also note that electric water heaters are a lot cheaper than propane ones.

  My Choice: Kenmore Power Miser 12 (50 gallon)

  I originally thought about getting a tankless electric, but they are not as efficient as tank heaters nor are they as quick to heat up as propane models. I also decided that I wanted to upgrade from 30 gallons (which would run out of hot water regularly if my wife and I took showers quickly in sequence or if we had guests) to 50. Then there was the matter of efficiency. Being the geek that I am, I would not settle for anything less than the highest insulation rating (to reduce standby heat losses) and a fast recovery time (the time it takes to heat the whole tank if it is filled with cold water).

  Before I checked anywhere else, I looked at Sears. Why? Because they are the “big sponsor” behind Extreme Home Makeover and I prefer to spend my money at stores that support such good causes. I was even willing to pay a little extra. As it turns out, they have the cheapest AND the most efficient water heaters! Their Power Miser 12 series has the highest insulation rating I’ve seen (R24), two anode rods (makes the tank last a lot longer), and a 12 year warranty. I ended up paying $270 for a 50 gallon model (signed up for a Sears card and got 10% off). Compare that with a $347 Maytag 50 gallon model that isn’t as good.

  Installation

  The existing water heater was sitting in the corner of a closet in my garage on a platform/drain basin combo. The water pipes came in from behind the unit and the incoming line was literally affixed to the top of the unit. In order to get it out, we had to cut the copper pipe. The propane line came in right next to the copper water pipes (which were sitting on top of CPVC—on a wooden block—unsecured to the wall!) and was attached to a T fitting that continued on to the furnace.

  Before we started removing the old water heater, we ran a 4-wire, 8-gauge electrical cable through the joists across the wall and hooked it up to the electrical box which was only a few feet away. There was an existing dual-20 AMP 220V circuit already in the box for a hot water heater. I suspect that an electric unit was installed before the propane one. What was kind of scary was that there was existing wire hooked up to this 220V circuit and it was only 12 gauge! We have no idea where that line runs, but I’m going to be doing some careful inspection today trying to figure out if there’s anything else in there that is equally as unsafe.

  The 8-gauge cable for the new hot water heater was too thick to fit through an existing opening at the top of the box so we had to re-route some wires. This was annoying and time consuming as we were a cautious sort and only moved one wire at a time. Once the cable was run, we left it unconnected in the box for when we were done hooking up the new water heater.

  Once the electrical prep was done, we turned off the propane at the tank, turned off the water coming into the house, and hooked up a garden hose to drain the water heater. Draining the tank took forever. It is amazing how slowly water moves when there’s no incoming water pressure. While it was draining we cut off the end of incoming water copper pipe and disconnected the outgoing hot water hose from the other one (outgoing hot). We also disconnected the propane pipe, cut it in half, and Solid soldered it shut (capped it). We then re-attached the capped propane pipe to the propane line and tested it for leaks via soap & water. No bubbles, no propane smell. I will be buying a real screw-on cap later this week regardless.

  When the tank was sufficiently drained, Solid threw it over his shoulder and hauled ass out to the edge of the driveway where he triumphantly tossed it for the trash pick up. I’m not sure what he was trying to prove… That he would easily risk seriously injuring himself for trivial tasks, or that he was strong enough to do it. I’ll leave that exercise up to the reader =)

  Once the old tank was out, I cleaned out the area behind it (~15 years of gunk build up) and Solid began work on replacing the fitting we just cut off. He’s surprisingly good with a MAPP torch and lead-free solder. Once it was on, we moved the hot water heater into the closet for a quick double-check before we started permanently attaching things. Turns out that the hoses we bought were just a smidge too short! We needed to raise the water heater a few inches in order for the outgoing hot water hose to reach. Since it was far too late to head to Home Depot for concrete blocks, we had a scavenger hunt.

  I thought I remembered where there were some bricks in the back yard… After scouring the yard with a flashlight for a few minutes, I was surprisingly able to come up with enough bricks to safely support the heater! Oddly enough, there was a whole cache of bricks scattered about at one corner of the yard next to the fence.

  Once the bricks were in place, we laid the drain basin down and then lifted the (much heavier) hot water heater on to our brick platform. It sat very sturdily as we proceeded to hook up and tighten the hose fittings. Once that was done, we proceeded to hook up the electrical wire and enable the “optional 5500 watt” heating element feature (since I bought above-spec cable and have enough amps). This required removing some panels and screwing in a bizarre little metal clip into the side of the heating element controller (note to Sears: WTF?).

  When everything was hooked up and we felt satisfied with the look of things, we turned on the incoming water and were delighted by the sound of the filling tank. No leaks. Compared to the near 45 minutes it took to drain the 30 gallon tank, it only took about 10 minutes to completely fill the 50 gallon one. Once it was filled, we hooked up the wiring in the electrical box and threw the switch to turn it on. Nothing happened.

  I’m not sure what I was expecting. It was extremely anti-climactic. A green LED light on the heater would certainly have been helpful. So we waited.

  After ten minutes, we checked the hot water in the kitchen (which was a bad idea since it has to be the slowest flowing faucet in existence). After about 5 minutes of air sputter and solder-smelling gas coming out, we had warm water! It was a success. The rest is history… Or at least a really long blog post.

  I’ll post pictures later since my wife is monopolizing the machine with the card reader at the moment.

  Some mundane details I didn’t mention:

• We hooked up an electrical box next to the hot water heater and had the 8-gauge wire coming out of it inside some really nice cable armor (flexible PVC tubing). Very professional-looking and it would make those “safety first” people proud (you know, “them”).
• Solid showed me a neat trick when we unhooked the vent: He duct-taped a plastic bag over the end of it and cut a small hole in the bottom. He then proceeded to fill the entire vent with Big Gap foam creating an air-tight seal. Very cool way to seal an open vent… I don’t have to worry about tape coming off or a cap falling down.
• I set the thermostat on the heater to 140 degrees. Why? Because if you set it to anything lower than 133 degrees, legionella bacteria can thrive inside your tank and possibly give you Legionnaires’ Disease. If you have small children I do not recommend this as it is in the “danger zone” for scalding.
• A 1/2 inch drill bit is good enough for 8-gauge, 4-wire electrical if you wiggle it around a lot.
• We used copper U bolts to permanently affix/support the copper piping to the wall. The previous tank installer did a real crappy job.
• The “main valve” coming into the house is far too unassuming. It looked like your typical garden hose spigot. It would have been much easier to find if it were more like the main valve in Joe Versus The Volcano. Now I can empathize with Joe.
• Electrical hot water heaters are absolutely silent. No more “whooooof” and hissing flame sounds.

• My garage is now a huge mess. I need to clean and put stuff away.