We have hard water where we live. Like, REALLY hard. Super hard. It’s like water on Viagra. When we moved into our house we soon discovered our natural gas water heater was doubling as a popcorn maker, poppity-popping for a half hour after the evening’s showers. It was only a few years old, so I spent a bunch of time, energy and money draining it, flushing it, descaling it, trying to remove the calcium deposits. For a while it would work, but the popping would always return.
Another problem we had with that water heater was the dip tube broke. That was fun.
Eventually, I got tired of that unit and bought a new one. That was fine, for a while. Then the popping began again.
Uhg. So, I’ve lived with that for a while…
Even though I’ve only had that water heater for about 15-16 months and I could get a lot more life out of it if I regularly drained and flushed it, I began to think it may be time to do something different. One of the issues we have with the old tank was that it was only 40 gallons, simply not enough for 6 people. For convenience and to keep costs down (I already had some idea I’d eventually be going tankless), I replaced the original tank with another 40 gallon tank. I became interested in tankless heaters some years ago, for their energy saving and convenience qualities. I began to research them, and learned you have to be kind of careful.
Many people make the mistake of buying an on demand water heater that doesn’t have the capacity that they really require. It’s very important to get the best unit you can afford. Watch for features such as a high capacity (gpm), freeze protection, electronic ignition, carbon monoxide protection, overheat protection, self diagnostics, and high efficiency rating. Most of the better units will have an energy factor of over 0.80, which will qualify you for a $300 tax credit through the end of 2007. Also look for a modulating btu range, and the higher the top number, the better it can keep up with the demands of your family.
The on demand tankless water heater I chose was the Paloma PTG-74PVP-1. This is a 7.4 gallon per minute heater with an efficiency rating of 84%, an energy factor of 0.82 and a modulating btu range of 19,000 to 199,900 btus, which is as high as I could find. It also has every feature you can think of. This unit normally sells at Home Depot for $999, but I purchased it on ebay for $600 plus shipping. Paloma makes an outdoor unit, which simplifies installation because it mounts to the side of the house eliminating the need to vent the exhaust out of the house. I bought the indoor model, and performed the installation myself.
Installation was a breeze, here’s how:
Here’s what I had to work with. There’s no good way to gain access through the basement walls of my house. The field stone walls are 2 feet thick and go all the way up to the subfloor, past the joists. The only plausible option then is to go through what was formerly a window. As you can see, the former owner had the same idea. On the left is the vent for the current water heater, which as you can see, is far from code. It’s single wall pipe, with no protective thimble, slants upward instead of downward, and the minimum clearances to combustibles wasn’t even considered during installation. Note the expanding insulating foam wad on the one side of the vent pipe and the duct tape on the vent pipe. Groovy.
I got started by ripping out the old vent and cutting the hole big enough for the thimble for the new vent. I then installed the new thimble and part of the vent.
The kind of vent I’m using is called Z-Vent, which is cuttable. This is good, because this comes into the basement too far.
Then it was time to hang the heater. These window wells are so big the heater would be on the floor if I secured it directly to the wall, so I decided to span the window well with a piece of galvanized steel.
Then I hung the tankless water heater. Now, doesn’t that look nice? Takes up a lot less space than the 40 gallon tank.
I then trimmed the vent to fit and connected the exhaust.
Then it was time to tackle the plumbing. I purchased an isolator valve kit. These are great, they allow you to turn off the hot and cold and disconnect the unit by the built in unions for service, tap off the hot or cold at the heater, or isolate the hot and cold lines and run descaling solution through the heat exchanger without unhooking anything. And, the hot side has a built in port for the temperature/pressure relief valve. An inline check valve should also be installed on the cold side.
I love PEX tubing because it’s so easy to work with, and will eventually replumb the entire house in PEX. Until that time, I decided to make temporary connections to the existing plumbing.
Cutting PEX is easy with this handy-dandy ratcheting cutter. Makes for nice, clean, straight cuts.
Copper rings are slipped over the end of the tubing, and the tubing slipped over the fitting. Then the copper ring is crimped with the PEX crimping tool.
Always check the rings with the ring guage. The guage has a ‘GO’ side…
and a ‘NO GO’ side for each size. It measures that the ring is crimped enough, but not too much.
Here’s the plumbing complete. Next it’s time to get the gas line run. Of course, always have gas work completed by a qualified gas technician.
Installation is nearly complete, all that remains is securing the plumbing and natural gas lines. Here I’ve temporarily mounted the water heater’s remote control to the left of the unit for testing. Works great! One nice thing about the remote is you can mount it in your bathroom, set it to whaever temp you want your bath or shower to be and turn on only the hot tap. What sense does it make to heat the water to 120 degrees and then cool it down to your comfort level by adding cold water? And this way, your shower is a steady 106 degrees (or whatever you prefer) during your entire shower.
