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.

I See A

While I was up in the northern reaches of Wisconsin, Jen attended the The Historic Chicago Bungalow & Green Home Expo and picked up some really neat information from tons of vendors on bungalow restoration and renewable energy sources.

Well I was kinda bummed that I didn't get to make it to the expo. So when I heard that last Saturday was national solar day with local tours across the country, I quickly went to the ISEA website (pronounced I-See-A) to find out what the local group had planned. To my surprise, they were planning a viewing of 4 different buildings right in Oak Park! One of the homes even featured the tankless hot water heater that we bought (but have yet to install) for our house. The homes all featured solar thermal technology, which captures the sun's heat using water and transfers to your home hot water heater, essentially pre-heating it. A large system can also pre-heat the return air in an HVAC furnace by running the solar-heated water through a heating coil. Kind of like an automotive radiator that works in reverse. As a bonus, I got to see a converted electric only S-10 pickup and a diesel Jetta modified using a "Frybrid" system. The owner told me he drives for free using used cooking oil from local restaurants(biodiesel). All in all a pretty exciting afternoon!

Getting back to solar thermal systems though, the event put the attainability of a solar system within reach. A professionally installed system, after rebates from the state and a minimal federal tax credit come out to several thousand dollars. But the components themselves are relatively affordable except for the collector plates that mount on the roof. So I'm thinking that before we close up our walls upstairs (yes, we're still insulating), I might run some insulated 3/4" pipe up. Although with copper prices so expensive, maybe PEX is a better choice.