I'm in Hot Water Now

It was my own fault that I thought I could flush my 12 year-old plus hot water tank without repercussions. In this case, having to turn off the main supply to the house and get a new water heater.

However, this gave me the chance to walk-the-walk and buy an on-demand, whole-house water heater. I've been recommending them to anyone who would listen, but had been procrastinating in replacing my own.

This model is a Bosch Aquastar with a pilot light, but there is a version with an electronic ignition. As a dedicated do-it-yourselfer (read cheapskate), I liked the idea of going to Home Depot, where it is available off the shelf, and having hot water back on line that afternoon. Well it didn't quite go that smoothly as you will read below, but the thought was right.

As you can see from the photo the heater is in a utility room next to the washer. This makes it easy to test how "instantaneously" the water heats. I can attest that it is virtually instantaneous.

There are only two objections that I have heard voiced to buying one:

  1. Can it supply enough flow if more than two things are running?
  2. Why aren't more people using them?

In answer to the first question, it has 1/2" piping (but there is a 3/4" model). The 1/2" version I got is spec'd to deliver 3 gallons per minute. If you have low flow faucets and showerheads, they are 1.5 gallons per minute or less, then this is at least two fixtures, full-on, at 100% hot water. Then there is the fact that some products like the dishwasher and clothes washer rely on a certain volume of water, not pressure. So even if the dishwasher, clothes washer and shower were turned on simultaneously, the clothes and dishes would still come out just fine.

I think more people aren't using them because of shear momentum. I would guess most people usually need a hot water heater in a hurry because their last one broke. They call up some plumbing service and get a new one. Since it's an unexpected expense they probably don't want to hear about something that is a couple of hundred dollars more.

Even when building a new home, there are so many decisions to make, who needs to argue with your builder about some new fangled technology he's never heard about?

In the end, it's about energy that has been too cheap to drive new behavior. This may be changing.

And of course there are the many advantages:

  • Unlimited hot water. Unless I run out of natural gas, I will never run out of hot water.
  • Longer warranty and greater reliability. Instead of a tank that lasts between 6 and 12 years, I have a device warranteed for 15.
  • Saves energy. I don't know how much, but I'm anxious to find out. I do know that I no longer hear the sound of my hot water heater burbling away as it tries to keep a full tank of water piping hot all through the coldest night just so I can take a quick shower in the morning.
  • I swear my hot water smells better. This may be pure fantasy, but my hot water doesn't sit around. It's made fresh.
  • It takes up a lot less space. In my tiny utility room I got back about 4 square feet.

Installation would have been easy for anyone with any knowledge of pipe soldering. I'd done some 25 years ago, and thought, "how hard could it be?" The pipes for the Bosch need to connect from the bottom, and not from the top as with a conventional tank heater. Therefore I had to reroute the pipes slightly.

I put together all the fittings, and soldered them. I was right proud of my arrangement and the neat layout. I turned on the mains from outside and went into the utility room to check for leaks. It was like the Trevi fountain. Water was spraying in fine jets in every direction. I'd even neglected to solder the new washing machine connection entirely. Two pounds of brass and copper started to lift off like the space shuttle, and before I could even start to turn around it went into orbit while water gushed out all over the floor.

Humbled, I tried again, this time honing my skills on a test rig before final assembly. The second time round was a charm with zero leaks.

The only additional item was the replacement of my 4" flue with a 5" one. That wasn't very difficult but did add to the expense.

In total, I'm extremely pleased with my new water heater, and highly recommend it.