Our water heater is was a natural gas burning model with a 50 gallon tank (~190 liters). It was already there when we bought this house, eight years ago, and when it recently failed it wasn’t unexpected, but still caught us a bit by surprise.
The broken water heater made me appreciate the luxury of hot water. It wasn’t leaking much (a little bit of water accumulated on the garage floor) but to stop this, I had to shut off the supply valve to the water heater, connect a drain hose, and open the relief valve. So there was no water pressure on the hot water line… which meant taking a shower, even cold, isn’t possible: the shower valve simply doesn’t let enough cold water through! π
Doing the dishes meant heating a pot of water on the stove, to then use it in the kitchen sink, mixing it with cold water. And then when the dishes are done, they need to be dried to avoid the water stains, of course. I never really thought about the fact that this is something the dishwasher also does! (the dishwasher is connected to the hot water line only, so we wouldn’t even be able to run it.)
Considering that we have solar panels, I always expected that we’d switch to an electric model (hybrid with heat pump) when the old water heater would fail. It simply seemed like the right thing to do. But after looking at everything that’s involved… we decided to go with a tankless natural gas water heater instead. π
First, there’s the cost for the device itself: the electric hybrid water heater with heat pump costs about US$2000 more than the tankless natural gas water heater. Which is exactly the same as the tankless natural gas heater after factoring in a US$2000 federal tax credit (what a coincidence!). For the tankless natural gas heater with high efficiency, we also get a tax credit, but it’s “only” US$600, so that’s the only difference between the devices. Not too bad, and if that was all, we would’ve made the switch.
But then there’s the electrical part, and this is what caught us by surprise. It was clear that the electric hybrid would require a 240V line, and running it from the electrical panel to the location of the water heater costs, ballpark number, US$1000. Okaaaay…
And then there’s the electrical panel. After adding the solar system to our house, it is full. There’s no room for additional circuit breakers. Which would mean that we’d need an entirely new electrical panel. I don’t even know how much that would cost, but anything around US$3000 would seem realistic because I’d fully expect that some wiring would also need to be updated, “to bring it all up to code”, as they say. π
Last not least, the tankless water heater includes a circulation pump, which our house didn’t have yet. I’ve always wanted one because hauling buckets around to catch the water before it’s hot when taking a shower does get old (we used that water for the plants). The circulation pump is not part of the electric hybrid water heater. If we’d want one… it would cost extra.
So it all would add up to perhaps US$4500 extra (or more) to have the climate friendly electric hybrid water heater, which would put the whole thing north of US$10000. Which already and inevitably leads to the reaction: wait, ten grand for a water heater?!
Our monthly gas bill in summer (cooking, water heater, dryer), is US$19. Taking the water heater out of that would probably mean a US$10/month saving? (I really don’t know.) Assuming that natural gas will get more expensive, we’d be looking at perhaps 25-30 years before we’d break even with the electric hybrid water heater… except that this exceeds the life expectancy of tank-based water heater, by far. The tankless system has a warranty of 15 years, and might last 20 years. A tank-based water heater is expected to last 8-12 years.
While we won’t be able to escape the electric panel update in the long run (electric cars, home battery), another consideration was that the electric hybrid water heater has a big fan and according to the installer, it runs permanently. Ugh. The tankless natural gas heater on the other hand has a smaller fan that only runs when the heater is operating. To reduce the impact of the noise to our living space, we’d have to relocate the water heater altogether, to the other side of the garage. (there are space constraints.)
For a newly built home, or a newer home, this is probably all much easier and almost makes it a no-brainer, but for our 1974-built house? In sum, it was a bit much, all in all.