This is the first of two posts about heating water in our kitchen. This post is about the tankless water heater I installed under our kitchen sink. The second post will cover how to make electric kettles fast in the US.

My starting point is our 130-year old San Francisco victorian house. The water heater is in the garage on the ground floor and our kitchen is on the 2nd floor. I assume the hot water pipes were retrofitted at some point, and they take a meandering route from one side of the house to the other before making their way to the kitchen, including a run on the outside of the building envelope where they’re only haphazardly insulated (I added the insulation). This meant a wait of several minutes from turning on the hot faucet to when actual hot water came out (and yes, lots of wasted water)¹.

The hot water lines to different parts of the house also don’t form a “loop”, and instead branch out close to the water heater, with independent lines going to the kitchen, washer and bathrooms. With that in mind I didn’t want to install a hot water recirculation system: It would only really have helped in one place and the energy loss from hot water continuously circulating in pipes outside the house would have been severe.

Instead I chose to install an 8kW 240V Rheem tankless water heater under the kitchen sink. Since I was already running 240V 40A power lines for our new induction range, adding another set of wires for the water heater wasn’t too bad. The heater is pretty compact and fitting it under the kitchen sink was fiddly but ultimately not a problem.

Online reviews for these types of units are very mixed. People (understandably) are not happy if their showers are cold. But for us, in this one-sink application, the heater produces very hot water instantly. The thermostat is not even cranked up all the way and I don’t think we rely on the full 8kW. Importantly, our cold-water inlet temperature here in San Francisco is relatively high (“almost tepid” is how I’d describe it) which means the heater has less work to do. In retrospect a 30A, or maybe even 20A model, would probably have been adequate.

I plumbed the water heater to the cold water line and capped off the hot water line under the sink rather than putting the tankless heater inline with the hot water from the garage. It takes so long for the garage hot water to make it to the kitchen that I don’t think there’s anything to be gained from letting the garage hot water “take over” from the tankless heater when the hot faucet runs for a while.

I also plumbed our dishwasher to the tankless water heater. As predicted by another Technology Connections episode this has significantly improved cleaning performance. That’s because, for its initial pre-wash rinse, the dishwasher doesn’t use its heater and just hopes that it’s supplied with hot water. That is now actually the case, making the initial rinse much more effective.

Overall I’m very happy with this little water heater. Having instant hot water for washing hands and rinsing dishes seems like a bedrock of modern civilization but we were without it since moving here in 2017. If you can make the required 240V high-current electrical circuit happen and maybe also if your cold water inlet temperature is not too low then I think under-sink tankless water heaters are a no-brainer for solving the problem of having to wait for hot water.

1. I would love to travel back in time and relive the scene when the hot water system was originally installed in our house. I imagine the plumber and the then condo owners standing in the kitchen after the work was complete, turning on the hot water and then waiting in eager anticipation for several long minutes for the water to start turning hot. Did they then pop a bottle of champagne? Did anyone comment on whether waiting this long was actually practical when doing common kitchen tasks? We’ll never know. ↩︎

We recently replaced our gas range with an induction one and it’s lot better. My main motivation was energy savings (we have solar, so electricity is “free”) and improved indoor climate. I don’t want to get into the whole gas-stove culture war and I’m personally open to the possibility that burning gas inside may not be all that harmful. But all else being equal, there’s no way a gas stove improves indoor air quality and given the other benefits it seemed like a good idea to make the switch.

I had two requirements when shopping for the induction range:

• Controls on the front so you don’t have to reach over boiling pots and pans to adjust the burners
• Actual hardware knobs so you don’t have to fiddle with a touch interface embedded in the cooking surface

The cheapest model to fit those criteria was a $900 (at time of purchase) Samsung model. The fastest burner can boost to 3200W which is decent but not outstanding. I’ve been tracking Impulse Labs which has battery-boosted 10kW burners but is currently only a cooktop and not actually shipping yet. Other ranges were slightly more powerful but also at least 3x the cost and so not worth it. I also did consider an upgrade option from Samsung with a dehydrator, but it was $600 more and I’m pretty sure I’m never in my lifetime going to dehydrate $600 worth of stuff.

The Samsung replaced a $5000 stainless steel 4-burner Thermador Professional. These kinds of stoves are an artifact of the inflated San Francisco property market: When condos and houses are put up for sale they’re given a lick of paint, some marble countertops and a flashy new stove that looks impressive for the open house. They’re not actually good for home use though: All four burners are the same size and huge, so that anything but our largest pan had flames licking up the sides, even at moderate power settings.

Figuring out the electrical wiring was fiddly, but doing it myself at least meant that I knew everything was going to plug in and work. If you read online induction range reviews and installation experiences you’ll see that many folks end up with the wrong kind of outlet or an outlet installed in a way where the big 40A 240V plugs with stiff power cords don’t plug in.

It’s now been a couple of months and it’s astounding just how much better the induction range is. I was expecting the cooking experience to be about similar or even for the induction range to be somewhat slower, but that’s not the case at all. I didn’t time the gas range, but I’m pretty sure the induction range boils water and heats up pans faster just because it puts the heat into the pot/pan instead of blasting most of it up the sides and into the rest of the kitchen.

And the ancillary benefits are many:

• The flat ceramic cooktop is so much easier to clean and you don’t have to manhandle cast iron inserts to do so
• Handles of pans and cooking utensils don’t get super hot from gas flames. You can lift pots off the range without using oven mitts or a tea towel
• The cooktop doesn’t get hot except for the area right under the pot, so less scary to have kids help stir
• When not in use, the flat cooktop is much more useful for setting down grocery bags and other stuff
• The oven is much larger and you can place two cooking sheets side-by-side. There’s even a storage drawer below the oven

Overall, it’s just so nice that cooking is no longer a flaming, sputtering inferno, and that it’s still fast.

The only thing that was nicer on the flashy gas range was that the oven racks ran on smooth roller bearing slides (the Samsung has crude grooves in the oven wall). The Samsung also comes with a digital clock which is not a pro because, like all appliance clocks, it’s invariably wrong. Amazingly the Samsung range actually connects to the internet and you can even use an app to set the clock, but it cannot sync automatically over NTP.

Except for our cast iron pans (which we frankly don’t use much) we had to get new pots and pans. And I had to install a stainless steel backsplash to cover an un-painted patch of wall, but that proved a boon because the backsplash has a shelf and hooks for hanging utensils.

Overall, if you can make the wiring and power work and you have the option, I heartily recommend switching from gas to induction, even if you go for a cheap induction range like we did.

This weekend I installed a Tesla Wall Connector and a Neurio W2 Power Meter and configured them for dynamic load management. Dynamic load management means that the EV charger will dial down the charge rate from 48A whenever the Power Meter detects that total load is close to the maximum load of the electrical service to the house. For houses like ours with 100A (or less) electrical connections that’s very convenient because we can charge our EV quickly without tripping the main breaker in the few brief instances where we’re both charging our car and running all the other electrical loads in the house.

You obviously should never do what I did and should always hire a licensed electrician and Tesla installer.

Parts

• Tesla Wall Connector. I bought this retail from the online Tesla store.
• “Tesla” Neurio W2 Power Meter. These can be had from eBay.
• Cable to connect Wall Connector and power meter. The part number is 1133339-00-A and I also bought one from eBay. It’s just a low-voltage, two-conductor cable with a 6-wire connector on one end. I’m sure it would be very easy to improvise but I couldn’t be bothered to figure exactly what connector it uses. The cable does have a fancy QR-code tag on it, but scanning it is not part of the setup. Update: A commenter on Reddit notes that the comms cables are sold out and also provided helpful details on how to put together your own comms cable.
• Breaker, electrical wire (eg. 6/2 or similar THHN if you’re using conduit) and other stuff for wiring the wall connector.

Installation

1. Install the Neurio Power Meter. There’s a good how-to video on YouTube. It’s unclear to me if the WiFi connection is required when paired with a Tesla Wall Connector but I added the antenna for good measure. The main challenge for me at this stage was finding a spot in our already busy electrical panel and fiddling with cables for CT clamps and so on.
2. Install the Wall Connector. Ours is installed right below our electrical panel with the power wire coming from behind.
3. Connect power meter and wall connector. I chose to drill a separate hole in the wall connector back-plate for the power meter comms cable instead of trying to run it with the power wires, mostly because the comms cable isn’t very long and that way I didn’t have to mess with trying to extend it. The Wall Connector has an elegant design where the power wires all attach to the back plate and then the face plate just slots on. Unfortunately the comms-port is not part of that scheme and is on the face-plate assembly. So you have to connect the power meter comms wires while balancing the face-plate and then secure the whole thing to the back-plate.
4. Initialize the Wall Connector. You can do this using the Tesla One app. The app is supposedly only for Tesla employees and 3rd party contractors but you can log in using a normal retail Tesla user account just fine. When you scan the QR code that’s on the Neurio power meter it starts showing up as part of the install and you can configure the CT clamps. Check if you need to “flip” them to ensure the meter registers power flowing in the right direction (“import” vs. “export”). At this stage you can also configure the max load where you want EV charging to start dialing down. Note that I didn’t configure the Neurio separately, it was all through the Tesla app.

Summary

We haven’t taken delivery of our Tesla car yet so I haven’t actually tested the dynamic load management. But I wanted to document this process since it does seem to work and the power meter registers with the Tesla app and site install and appears to be recognized. I’ll update this post when I’ve confirmed the setup works and throttles charging when we’re using all of our other appliances.

This is very exciting to me: For years a broom has been stashed in drain vent on the side of one of our neighbors’ house (a couple houses over). The house is currently on the market so I went to the open house, made polite conversation with the real estate agents and then proceeded up to the patio and took the broom out of the vent and put it on the deck.

I don’t fault the folks that used to live there for storing the broom in the vent. For them it was probably a convenient and out-of-the-way place to stash a bulky and infrequently-used implement. But for me, every time I gazed out over the San Francisco Bay from our patio my view was marred by an upside-down broom sticking out of a vent at an odd angle.

This post details how I replaced the noisy plastic wheels on a Little Tikes push car with high-quality rubber-coated steel wheels. The default wheels are probably OK for grass but on pavement they make a deafening grinding noise and I felt bad for my neighbors (and my son) just going one block over to the park behind our house.

To be clear, upgrading the wheels doesn’t make economic sense: A push car with noisy wheels costs $60 and the “whisper ride” model with rubber-coated wheels costs $80. Four steel wheels will set you back about $40 before considering time and additional parts. But we were emotionally attached to our push car and I thought it’d be a fun project.

Before switching out the wheels I did try just hot-glueing strips of old bike-tires to the plastic wheels but that didn’t last.

Wheel Change Instructions

Materials:

• 7″ steel wheels. I used these 7″ x 1.5″ ones.
• Assuming your wheels have 1/2″ ID ball bearings and the axle rod on the push-car is 3/8″ you need 3/8″ ID x 1/2″ OD metal sleeves of some kind. These are not strictly required but the wheels wobble without them
• 3/8″ push nuts (you may be able to re-use the ones that come one the car if you take them off carefully)

Steps:

1. Yank the axle-rods off the bottom of the car. The axles snap into the bottom of the molded plastic car body
2. Get the push nuts off the axle ends and take the old wheels off
3. Press the 3/8″ x 1/2″ sleeves on the axle ends. This may require some combination of sanding, lubrication and hammering
4. Mount the new wheels on the sleeves on the axles and put the whole thing back together.

UPDATE: As of December 2023 it appears that the HomeBridge plugin is no longer working, possibly because MrCOOL added additional CAPTCHAs or other validation when logging in.

Last year I installed a DIY 4-zone MRCOOL mini-split in our condo. Once I got the system running I wanted to control it through Apple HomeKit. Unfortunately MRCOOL only integrates with Amazon Alexa and Google Home.

I already run HomeBridge to tie together some of our home automation and a supposedly MRCOOL-compatible plugin was available. The plugin is called “smart-cielo” because many mini-split systems on the market share components but are sold under different brands in different configurations, “Cielo” being one.

Until recently the HomeBrdige plugin didn’t actually work with my particular system, but that’s now fixed!

From memory, here’s a rough guide to using a MRCOOL mini-split with Apple HomeKit and HomeBridge.

Prerequisites:

1. MRCOOL mini-split with WiFi smart controllers setup and working and you can control your mini-splits from the MRCOOL iOS app
2. HomeBridge running and working with HomeKit Home Hub. I run HomeBridge in a Docker container on a server in our home, but any HomeBridge setup will work
3. The network MAC address of each mini-split head unit wifi controller. You can find the MAC addresses in the MRCOOL app or in the admin interface of your WiFi router

Steps:

1. Install the smart-cielo HomeBridge plugin. If you have trouble finding it, the GitHub issue has suggestions for search terms
2. Configure the plugin with the username (email address) and password used in the MRCOOL app (this is the password used with the HTTP API that the plugin interacts with to control the head units)
3. Plug in the MAC address for each head unit in the plugin setttings
4. Check that it works!

Alternatives

Before the HomeBridge plugin became available I researched and experimented with a couple of other options for integrating “dumb” mini-splits into smart home setups. My notes might be useful is you’re reading this and don’t want to get into HomeBridge. The least broken option I found is the Sensibo Air, and I bought two. They do work (by sending infra-red signals to the head-unit like the normal MRCOOL remote). But overall I think the Sensibos are way overpriced for what they do, and I don’t recommend them. I also remember being annoyed by the requirement for a monthly subscription to access more advanced features.

The best alternative to a HomeBridge HomeKit setup is probably to just stick with the MRCOOL app. It’s clunky and the automation options are simplistic, but once my excitement about HomeKit integration dissipated I found it to be mostly good enough. The reason is probably that the mini-splits are per-room, so getting up and using the remote control is easy. Unlike the whole-house furnace that could only be controlled from the hallway thermostat (before installing an ecobee).

In case you didn’t know, wall outlets with USB ports are a thing. They’re neat for a couple reasons:

• Cleaner look, no wall-wart chargers hanging off the wall or falling out the socket
• Always there and don’t disappear because someone has to quickly pack for a business trip
• 110V receptacles can be used for other things that USB-chargers

When we moved in 2017 I installed outlets with USB-A ports in a couple of strategic locations and really liked them. The most-used locations are the kitchen and hallway where we tend to charge phones, bike-lights and so on.

I also installed an outlet with USB-ports behind our bed headboard to charge phones at night. This works fine, but in retrospect was it also relatively pointless: There’s already power strip behind the headboard to power reading lights and other stuff so the USB outlet doesn’t make it any cleaner or more convenient than a wall-wart in the power strip.

12W USB-A type outlets were fine for 2017: USB-C wasn’t all that common (at least not for charging phones and tablets) and you couldn’t get outlets with high-power PD type USB-C ports anyway. That left me without an elegant way to charge our USB-C/Thunderbolt-port laptops. Without having done any research, my understanding is that Ultrabook-style Windows laptops generally require at least 45W to charge, and can typically accept higher charge rates. Way more than what comes out of the USB-A ports.

Laptop charging around the house became less of a problem with the pandemic because both my partner and I now haw full-featured home desk setups that we plug into, but a new one cropped up: HomePod Minis. These are in plain sight in our kitchen and I never really liked the look of the 20W wall-wart with a wire snaking down to the inevitable coil around the base of the speaker. HomePod Minis originally required the full output of the included 20W charger, but a software update dialed that down to 18W—still too much for USB-A outlets.

I’ve periodically checked for outlets with higher-power USB-C ports, and they finally starting showing up this past year. I was slightly annoyed it took so long since it’s an obvious improvement and 3rd party wall-wart manufacturers like Anker were perfectly capable of churning out GAN-based chargers that would fit within the envelope of a standard US wall receptacle. I guess safety regulations, heat-dissipation and reliability requirements combine to make designing a wall-plug receptacle integrating high-power USB-C ports harder than it seems. 

Regardless, we’re now spoiled for choice and you can get outlets with (at the time of writing) up to 60W single-port output, enough to charge even relatively powerful laptops. When deciding which ones to get, I was tempted to spring for the most powerful (and expensive) option, also because installing outlets involves turning off electrical breakers and is generally annoying and not something I’d want to do again later to upgrade. But I ended up going for a much cheaper dual USB-C ELEGRP model with 36W max output (18W per port) that I can’t find on Amazon anymore.

I chose those partly because they’re powerful enough to power our HomePod Minis and high-output MagSafe chargers, and partly because I’ve largely switched to Apple Silicon Laptops that have much lower power draw. In fact, both my M2 MacBook Air and (work) M1 MacBook Pro can charge (albeit very slowly) off the old USB-A style outlets (I’m sure someone’s going to point out in the comments that one should only use a proper Mac charger and that I’m ruining my laptop batteries and so on, but I’m going to go ahead and assume that whoever designed the charge controller chose to add support for those charging speeds because it’s safe).

So there you have it: Wall outlets with integrated USB charging ports are awesome and are now powerful enough to power small speakers and even laptops, in addition to charging phones and tablets. And outlets with built-in USB ports look much cleaner than wall-warts that fall out, go missing and take up an outlet.

This post covers how I upgraded our home thermostat from a battery-powered two-wire setup to an Ecobee3 Lite supporting both heating and fan-only modes. I wanted the fan-only mode to circulate air in our two-level condo where hot days often result in a hot and stale 2nd floor and a frigid 1st floor.

Note that I’m neither an electrician nor an HVAC pro and it’s very possible that what I did is a very bad idea. But it worked for me, so I thought I’d share.

Our house only has two wires running from the thermostat mount in the condo to the furnace in the garage, just enough to complete an electrical on/off circuit used to tell the furnace whether to heat or not. This is the dreaded “no C-wire” situation with no way to power a smart thermostat and no way for the thermostat to tell the furnace to just run the air circulation fan. Our furnace is relatively modern and has more wire terminals, but running additional wires from the condo down to the garage was not really an option.

To overcome this I bought two items:

• A 24V transformer that’s plugged into an outlet near the thermostat mount inside the condo. This powers the Ecobee
• A Fast-Stat Model 1000. This gizmo consists of sender (inside) and receiver (furnace) components. It works by multiplexing additional control signals (for fan-only, in my case) over the single installed wire-pair. Higher-model-number Fast-Stats can provide more virtualized wires, but I just needed one

The first step was to install the Fast-Stat. It comes with easy-to-follow instructions and wiring it into our furnace’s clearly labeled bread-board-like circuit board was relatively simple.

With the Fast-Stat installed I could run both heating and fan-only modes using the old dumb thermostat, validating that it’s working correctly.

Next, I mounted the new Ecobee and wired it up with the wires from the Fast-Stat and from the 24V transformer. The first time I did this, I got it wrong. I wired the transformer wires to C (“Common”) and R(c) (for “Red-Cooling”, I believe) and put the black wire in R(h) (for “Red-Heating”). I guess I thought that the Ecobee wanted it that way because it’s going to be running the heating system (hence R(h)) and the transformer instructions said to connect to C and R(c) wires.

With that ready the Ecobee turned on fine and all the wires showed up in the Ecobee configuration interface. Heating even worked! I couldn’t make the Ecobee run the fan-only mode, however, and at this point I actually gave up on fan-only for a couple of months, happy that I could at least control heating using the fancy new smart thermostat.

This weekend I had a chance to fiddle with the thermostat some more, and managed to get everything working. First I tried just connecting the G (“Green”) terminal (which runs just the fan) to R(h) with a piece of wire and the fan duly started whooshing air around. This was not surprising since the old dumb thermostat could to that too, but at least it showed that the wiring and connections on the Ecobee mount were OK.

Then I tried simply reversing the inputs to the R(c) and R(h) terminals so the transformer wire went to R(h) and the furnace control wire to R(c). In that configuration the Ecobee wasn’t getting any power and wouldn’t turn on. The breakthrough was to simply jam both the transformer and the furnace control wire into the R(c) terminal of the Ecobee mount. Re-reading the Ecobee instructions that makes some sense because the Ecobee wants to always use the R(c) terminal for systems with only one R-wire.

In spite of much googling I never found complete instructions for combining a 24V transformer and a Fast-Stat to make an Ecobee work for both heating and fan-only with a two-wire system. I hope this post helps others with the same setup.