Thanks for Tank and Tankless Heaters

Last weekend, Jim and I finished making the final connections for our tankless water heater. I was admittedly nervous since this is a used Takagi TK2 tankless water heater we had gotten off of Craigslist. So rather than just cutting out the old tank model, we installed a shut-off isolation valve on our old water heater and left it in place for now. That way, just in case we run into problems with the tankless and need to revert back, it's a simple switch.

So, once the new equipment was in place and water lines were soldered together and leak free, we flipped the switch on the tankless water heater. Water flowed in and no leaks! I turned on a hot water tap, and water began to flow through the tankless. Once the flow was high enough (more than 0.5 gallons per minute), the electronic igniter lit the flames, which we could see through a tiny window (Jim is pointing to it the photo). Then the exhaust fan kicked on to push the fumes out the special stainless steel venting. Shortly, there was hot water flowing through the tap! Yay!

In a tankless water heater system, the hot water takes a bit longer to reach the taps than a regular water heater would. This happens because there is no constant heat source heating water all the time, and no standby heat is transferred to the water pipes. This is a trade-off with a tankless water heater. Less fuel is needed to heat, but more water is used and wasted down the drain as you wait for the hot water. Fortunately almost all of our plumbing runs are relatively short, so we haven't noticed this isn't a big deal. It takes maybe an extra 20 seconds at our furthest plumbing fixture.

Anyway, we've now been living with the new tankless for a week. Sunday night, Jen was very happy to finally be able fill the bath tub with hot water instead of running out halfway through! But we noticed when taking a shower that the hot water fluctuated off for about two minutes (completely, so it was cold!) and then came back on.

I read the TK2 manual, did a bit of research, and found a great discussion on problems with Takagi TK2 water heaters. This gave me some good ideas such as cleaning water inlet filter, cleaning the igniter and flame sensor (next to the tiny burner window) as well as checking the temperature sensors in the water intake and outtake lines for any clogs. So I did all this. At first, looking at this thing with the cover off is quite intimidating, but if you try to look past all the electronic wires, it's relatively straightforward.

However, after all these maintenance tweaks, it seems we still have occasional problems with the shower. We still get hot water there (and everywhere else for that matter), and there is no problem if the shower is set to full-hot (not mixing with cold water). I wonder if this is mixing valve issue so we'll have to do a bit more investigation on the temperature fluctuations (and maybe even call Takagi) to get this figured out.

Anyhow, despite these initial problems, I'm quite pleased with the fact that the system works, and I'm really looking forward to cutting out the old tank-style water heater and getting some extra space in the small utility room / shop area in our basement. But we'll hold off on that until these issues are resolved, knowing that if needed, we can fire up the old beastly water heater at any time.

Going Tankless: Part II (for Real)

Remember when our water heater went out and we thought about getting a tankless water heater? Ah, the memories. It was in May 2006, but it seems like only yesterday that I was replacing that thermocouple. Wait, that's because it was yesterday! What do I mean? Well, the thermocouple went out again already.

Yes, I fear the 23-year-old water heater has reached the end of its useful life. I've replaced the thermocouple again, but how much longer can it go on? It's time to replace the entire water heater. Since the old beast is so layered with sediment that it won't even fill up our bathtub, this replacement isn't exactly a shock to us.

In fact, after it went out in 2006, I actually found someone on our beloved Craigslist selling a tankless water heater that had been installed in a mulit-family home for a few months. While the owner was glad at the energy savings, the residents weren't too happy when four people tried to shower at once.

If you aren't aware of the main performance difference between tankless and regular water heaters, the tankless design can't accommodate the same flow rate (gallons per minute) as a traditional heater. But as long as you get the right size, it isn't a problem. For exmaple, the unit I purchased is a Takagi TK2 which supports two major appliances. So although we never do laundry at the same time as showering, in theory, with this tankless heater, we could.

So while we limp along on our old standard heater, I contacted my good friend Jim, to help with the tankless installation since he has the exact same model. Also, there are some unique install considerations for these. Since tankless water heaters burn so efficiently, you can't use a standard exhaust duct... it has to be double-walled stainless steel. Jim also installs solar thermal water heaters, so he could help me install this so that if I ever wanted to go solar later on and use the tankless as a supplemental backup (a common configuration) there would be room to cut in the solar piping. Anyway, here's another photo of it during the installation process.


As you can see, the space-saving design is already a bonus as it tucks away into a 2'-wide space between the furnace and a foundation wall. I've already got plans for the area where our old water heater currently rots rests. Anyway, we're not quite done with the installation just yet, but we'll be wrapping things up very soon.

International Water Heaters and Electric Showers?

In mid-April, we took a brief break from Humphrey House to take a well-earned vacation to Ireland with our friend Jerry and visit some of his family. Of course we took lots of photos of the many interesting sites. There were even some neat things related to construction such as building with local materials (amazing number of slate roofs and stone facades), and a proliferation of renewable energy (lots of solar water heaters, geothermal heat pumps, and large-scale renewables such as wave power and wind turbines result from favorable sustainability incentives).

We got hands-on with some interesting construction when we stayed with Jerry's and his cousin John's home outside of Cork. Besides being an excellent cook, and great guide as we traveled through Ireland, John lives in a fairly recent home (constructed within the last 10 years). At John's house, I of course was interested in the building techniques (such as no basement since Ireland is actually considered in the tropics and has palm trees) while Jen was fascinated by the gardens and chickens.

While the 3-bathroom home has a small oil-heated tank water heater, the upstairs shower actually had a unique feature - an electronically controlled shower valve that incorporates an on-demand water heater (similar to tankless water heater technology, only smaller). We came across this shower control in a couple locations during our travels.

At first, it was a bit confusing as Jen and I were both unsure how to turn it on. Once we figured it out though, we felt dumb because it was pretty obvious. These electric showers are really unique because they are connected to the cold water supply lines, and you just dial in the temperature you want and turn another dial "on" to activate it. This makes them more energy efficient, use less water, and surprisingly, there weren't any performance issues. John told me the two big manufacturers of these are Triton are Mira (owned by Kohler).

It was interesting to see how Europe (Ireland in this case) is more advanced and hold concepts like sustainability as integrated into their core. In many ways, the Irish haven't had a choice - they've had to be self-sustaining and conserving of their resources since they live on a rocky island with limited resources. So besides having a great vacation, we got a bit of education in how other parts of the world approach green building.

Going Tankless

On Friday morning, a piercing scream woke me better than any alarm ever could. I soon discovered that Jen was rudely informed by our plumbing system that our hot water heater had given out and was no longer working. Unfortunately, this was while taking a shower. Not the best way to start the morning.

I fooled around with the pilot light for awhile trying to relight the burner. The pilot light would catch, but as soon as i released the priming button to turn the burner on, the flame would go out. After work, my stepdad told me that it was likely due to the thermocouple going bad. This little copper safety device ensures the pilot flame is present. When heated by the pilot flame, a small electrical signal is generated and sent to the main gas control valve. In the event of pilot flame failure, the electrical signal is no longer generated, and the main unit shuts off the gas flow to the burner equipment. So when our electrical signal was gone, so was our water heat. Fortunately, this was a fairly easy replacement, and it only cost a whopping 4.95 for a new thermocouple!

So the water heater limps on, and we have hot water again. But the whole event got me thinking about replacing our 14 year old water heater when we redo the rest of the plumbing in the house. I've heard about tankless water heaters for awhile. They've become standard in green building technology. Low water usage, no standby heat loss (you only heat water as you use it, "on-demand", instead of constantly heating a 50 gallon tank of water all the time), and very small space requirements. The technology has been used elsewhere in the world where water is a premium (Europe, Japan), but has only recently caught on in the US.

An excellent overview of how tankless water heaters work is provided on the Takagi website, as well as other providers (Bosch, Rinnai, Paloma). Basically, you never run out of hot water... the tank can always heat water on the fly. The biggest disadvantage is that you need to get a large (read: expensive) tankless heater if you expect to have more than 1 "major application" at a time. This means 2 showers or 1 shower + dishwasher. Most can support 1 shower + a sink. But they last a LONG time, manufactures claim 20+ years. Some people say even longer.

The only other bad thing is the initial cost. It's about twice as much as a traditional tank heater. For a model that provides for 2 major applications, it is about $1000 (they also need special ventilation too). But part of this cost can be offset since because they are about 85% efficient, they qualify for a $300 energy credit for next year's taxes.

All said and done, I think the pros may outweigh the cons. In addition to the cool sustainability points for being green (and saving greenbacks in terms of nat. gas costs), I really like the space efficiency aspects. We'll have to do more investigation on these tankless units. Any feedback or insight is welcome!