What's Your Hot Water Setting?

For the past few weeks, I've been turning my boiler completely off at night. This came about after I went down to the basement one day to throw in a load of laundry and found that my boiler was running. In June. The only thing it would be running for in June is hot water, and I hadn't called for any hot water, since I'd just gotten home from work.

You see, I have what's called "residential hot water," or "tankless" hot water. There's a small reserve tank, but that's just for water that my furnace heats; I have no hot water heater, per se. I realized that day that the furnace actually runs, all day, to keep the reserve tank at the right temperature. So, at night after my shower I've been going back to the basement and turning the emergency power switch to the furnace to "OFF," and it doesn't get turned on again until the next evening when I get home from work. The reserve tank insulates the hot water well enough so that I have enough warm water to wash my hands in the morning.

Tonight, though, when I went downstairs to turn the thing off, I decided to check the temperature to which the boiler was heating the water in the reserve tank...

Let's back up here. Here's some background info, before I tell you what temp the tank was at:

"Popular Mechanics" (November 2005) says "A factory setting of 120 F on a new residential water heater is recommended (and is sometimes mandated by state law) because it is the highest setting considered to be safe; higher temperatures can cause severe scalding.

"According to the Shriners Hospitals for Children, a person exposed to 140 F water for about 3 seconds receives a second-degree burn and after 5 seconds will have a third-degree burn. At 120 F it will take approximately 5 minutes to receive a third-degree burn. It can take less than half that time for a child to be scalded."


Well, folks, my hot water heater was set at 180 DEGREES.

Needless to say, I was pissed. Now, I knew it was hot (I do, after all do a ton of baby/breast pump dishes by hand every night). But not THAT hot. So, not only had I been wasting precious oil by keeping the boiler on day and night, but I'd REALLY been wasting oil (and creating a dangerous situation in my house with an infant around) by having too-hot water coming out of the tap. In my opinion, the hottest water that comes out of your tap should be just hot enough to stand without adding cold water, because if you have to add cold water to hot water, aren't you kind of defeating the purpose of heating all that water?

Anyway, lesson learned. My aquastat is now set at 120 degrees, but I'm still turning off the boiler at night, because I'm a cheap Yankee, and damn proud of it.

Check your aquastat today!

Addendum: I had meant to mention that I'm mostly pissed with my oil company, which also services my boiler, because they MUST have known that the aquastat was set so dangerously and wastefully high. Hell, they may have even set it at that temperature. At the very least, they should have been checking it during annual inspections! I certainly have never, ever opened up the panel that houses the aquastat. I only found it by dubbing around; it's totally not obvious or easily accessible. I would switch oil companies tomorrow if the oil company owner weren't my next-door neighbor, and if she weren't a darn sweet 80-something widow who thinks my son is just adorable. Sigh...