See the little green light? That means it's all heated up. When the light turns orange, it means it's in the process of heating. If the light is orange, we know not to run the electric kettle, the stove, and/or the oven, because the combination will (and frequently does) blow the fuse.
I like the little sticker next to the green light. It tells you what to do if something bad happens.
No light equals sad face. Telephone arrow fat guy with wrench!
Several people (notably our landlord and the people who rented this apartment last year) have suggested that we can save energy (and save on our energy bill) by turning the hot water heater off during the day (when electricity is more expensive) and turn it back on at night. The tank holds enough hot water to allow for our showers and dishwashing, so there's no problem there.
The problem, as Maggie discovered with a little online research, is that shutting off electric water heaters lowers the tank's water temperature enough to encourage the proliferation of a bacteria called Legionella, which can cause Legionnaire's Disease. (Heaters using fossil-fuels are not at risk, for whatever reason.) Legionnella mostly seems prevalent in non-municipal water systems, and can only be eradicated if the tank temperature is set to 140 degrees Fahrenheit or higher. This creates another problem, since 140 degrees can scald pretty badly. Our water is certainly municipal, and Legionella seems mostly to affect those with already-compromised immune systems. So it's hard to tell just how seriously dangerous it is to turn off our water heater.
For now, au cas où (just in case), we're keeping the water heater on. But we'd love to hear from anyone who has experience with this kind of thing, or happens to know anything about the issue.
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Saw this when I was reading the delightful discussion you were having with Mike yesterday. It's probably not a big deal. You don't ever drink the water that's been sitting in the water heater, right? So that eliminates a major source of risk already. Probably heating the water to 140 degrees periodically (every few weeks?) is all that is necessary to cut down potential legionella growth, provided you don't have a severely compromised immune system.
ReplyDeleteIt seems like the biggest culprit for ingesting legionella isn't drinking water but rather vapor from showers. But I agree with you - we're probably not at risk.
ReplyDeleteThen again, I've had this darned cold for two weeks and it shows no signs of going away, so who knows? Maybe I should alert the French CDC . . .
You're right about that little sticker. It does say it all. By the way, that tip is right. You can save energy if you turn the system off during the day, then turn it back on during the night. It's not worth the risk if you're up against the Legionella.
ReplyDeleteLegionella may be hard to kill due to the fact that you need to raise the temperature of your water heater to the point that it can scald and burn your skin. The best possible solution here is to buy scald protection devices. These tools basically separate the flow of hot water from the cold water, and some tools mix the cold water with the hot water before it comes out of the shower thus providing warm and relaxing water.
ReplyDelete