Long version:
For most of the winter the on-demand water heater wasn’t paying attention to our demands. Sometimes it would take several tries to get hot water, sometimes it would come right away, sometimes it would never come. It seemed to work better with the cover off and seemed like it might be tied to the temperature outside (it’s an outside mounted unit).

We had a plumber that works on Takagi water heaters come out to try and figure out what was wrong. Various searches on-line turned up some people with similar problems but with no answers. The blink code from the heater itself indicated one of three things and I never purchased the remote temperature unit because I never saw a need to change the temperature once it was set. It turns out it’s more useful to let it tell you specific error codes. The plumber tore apart the unit and found everything looked good, even the heat exchanger which is usually the part that causes intermittent problems with hard water deposits.

The plumber called the Takagi support people. They conferred and the plumber came back another day (no extra charge) and he checked some more things and then called the Takagi guy and did some more things with him on the phone. Still no answers. The plumber called back a few days later saying there had been more conversations with the Takagi guy and they came to the conclusion that it was probably a little internal spinning part that was frozen with hard water deposits and that it needed to be flushed. I was skeptical because the gas was flowing and a spark could be seen which means everything is starting up normally, it just wasn’t actually igniting.

The plumber gave me the Takagi guy’s phone number and after telling him everything and saying I disagreed with the stuck part theory because it wouldn’t be so reliably related to temperature and it wouldn’t be affected by the front cover being off. The Takagi guy said I needed to check the spark by pulling off the ignition wire and holding it an inch from the manifold. I should see a nice blue spark but instead I saw nothing. At about 1/4″ I saw a weak orange spark. Takagi guy said the problem was the ignition wire and that I should try cutting an inch off the end and reattaching the connector. When I did that I realized the connector was glued on and wasn’t going to be reconnected. I jammed the end on to the terminal and sure enough it was more reliable, even without the normal connector on there. Unfortunately the cable was glued into the igniter as well so I needed a new igniter and cable. It was out of warranty so it was $42 including shipping and handling. The installation took five minutes and the new one has a cable that isn’t glued in which will be helpful if this happens in the future.

Once home I verified the wasp was still there and then I just had to wait for the wasp to get within reach. I wasn’t about to get on a step stool since I figured I might seriously hurt myself in an escape attempt. I had to wait for it to crawl down to spray it, and then a second time, and then a third time, and then a fourth time. Kills in seconds is true when it’s about 1000 seconds. I was just outside the kitchen waiting when I heard it fall to the floor. I looked just in time to see it right itself and fly into the kitchen window where I lost sight of it.

I looked carefully in case it was just pissed off and waiting to strike, but I saw no evidence of a wasp. While I waited I munched on the snack food I bought when I got the bug spray so I wouldn’t be subject to another sneak attack in the kitchen. A couple hours later and I looked more thoroughly and still no sign of the wasp. My best theory is that it crawled under the window in the track but moving the windows hasn’t turned up a body yet. I’m satsfied I won’t be troubled by that wasp again.

I found on some random hardware message board with messages from a few years ago discussing motherboards with similar failures. They were from about when I got mine (6 years ago) and the failure apparently was drawing too much current from the power supply, making sure to take the pwoer supply with it.

I was planning to do the computer upgrade next year and wasn’t really prepared for this, but I kept in mind my goals for the new machine: to be quiet, to be energy efficient, to be relatively inexpensive, and to be upgradable. I picked up a low-end motherboard sporting AMD’s most recent CPU socket since they change sockets less often than Intel and upcoming processors will be backwards compatible. The CPU is an AMD X2 4600; I’m coming from a dual AMD 1900 world so the speed bump isn’t as huge as it might be coming from a single processor, but the tripling of the RAM speed makes the difference quite noticable. An extra bonus, my old CPUs were about 70-75W each, but the new dual core processor is just 65W by itself and it can be clocked more slowly when not in heavy use for even more power savings. The motherboard has pretty much everything built into it so I have no extra cards installed right now which also helps with cooling and air-flow though if I can’t get the on-board graphics to start driving two monitors I may have to resort to buying a video card.

The RAM was a good brand and on sale so I picked up 4GB. The only thing that kept the previous set of hardware from feeling old and slow after 6 years was the 3GB of RAM in it so I knew I didn’t want less than that.

I wanted to keep my hard drives since they have plenty of life in them. The only problem is that modern motherboards are all Serial ATA and I have old-school drive interfaces. So I picked up some adapters for them that I had only heard would exist when Serial ATA came on the scene. Despite seeming a little sketchy with not even a sheet showing what to hook up and just being a bare circuit board they work perfectly!

The new power supply is an Antec NEO HE (high efficiency) power supply. It’s definitely the heaviest PC power supply I’ve used. It is part of the new wave of pwoer supplies that is about 20% more energy efficient, which means it hovers around 80% efficiency. It controls its fan based on temperature, but with not enough noise that I can hear so far. Another nice feature is that you only plug in the cables you will be using in the system so there is no need to find a place to stash all those loose ends; yet another bonus for air flow!

The result? Something much faster, much quieter, much more energy efficient, and hopefully a platform that will last awhile. Oh yeah, a most of the components are RoHS compliant which means they don’t have the usual nasty stuff used for building electronics.