This is a really interesting read. And has links to some similarly interesting stuff. Anon's takeaway? It just might be possible to rig a hydrogen gas explosive device in someone's home remotely. And probably succeed in making it look like an accident to investigators.
How I upgraded my water heater and discovered how bad smart home security can be
Could you really control someone's hot water with just an email address?
Kevin Purdy - 5/17/2024, 6:00 AM
The hot water took too long to come out of the tap. That is what I was trying to solve. I did not intend to discover that, for a while there, water heaters like mine may have been open to anybody. That, with some API tinkering and an email address, a bad actor could possibly set its temperature or make it run constantly. That’s just how it happened.
Let’s take a step back. My wife and I moved into a new home last year. It had a Rinnai tankless water heater tucked into a utility closet in the garage. The builder and home inspector didn't say much about it, just to run a yearly cleaning cycle on it.
Because it doesn’t keep a big tank of water heated and ready to be delivered to any house tap, tankless water heaters save energy—up to 34 percent, according to the Department of Energy. But they're also, by default, slower. Opening a tap triggers the exchanger, heats up the water (with natural gas, in my case), and the device has to push it through the line to where it's needed.
That led to me routinely holding my hand under cold water in the sink or shower, waiting longer than felt right for reasonably warm water to appear. I understood the water-for-energy trade-off I was making. But the setup wasted time, in addition to potable water, however plentiful and relatively cheap it was. It just irked me.
Little did I know the solution was just around the corner.
Hot water hotspot
I mean that literally. When I went into the utility closet to shut off the hose bibbs for winter, I noticed a plastic bag magnetically stuck to the back side of the water heater. “Attention! The Control-R Wi-Fi Module must be installed for recirculation to operate,” read the intense yellow warning label. The water heater would not "recirculate" without it, it noted.
Getting weird with other people’s water
“I thought this was crazy until another GitHub user reached out and we started collaborating and came to the same conclusion. You could control any Rinnai water heater that was connected, as long as you knew the registered account's email address,” Barbour wrote me.
Full article at : https://arstechnica.com/gadgets/2024/05/how-i-upgraded-my-water-heater-and-discovered-how-bad-smart-home-security-can-be/?utm_source=pocket-newtab-en-us
Drain Water Heater to Avoid Gas Buildup
October 23, 2004 at 1:00 a.m. EDT
QDEAR BARRY: My vacation home sits vacant for several months at a time. When I return, the water always has a strong sulfur smell, like rotten eggs. What could be causing this problem? Is it unsafe? How can I keep it from happening? – Patrice
ADEAR PATRICE: Water heaters contain a specialized metal rod known as a sacrificial anode. Its purpose is to absorb the corrosive effects of minerals in the water and thereby prevent deterioration of the water tank. Gradual deterioration of this rod produces small quantities of sulfur and hydrogen gases. When the water heater is used daily, these gases pass from the plumbing system without being noticed. When the house is vacant and no water is drawn from the tank, the sulfur and hydrogen accumulate. The sulfur dissolves in the water, causing the rotten egg smell you notice. The way to eliminate this smell is to drain the tank to the yard, by way of a hose.
The sulfur itself isn't harmful; hydrogen, however, is highly combustible. Hydrogen accumulates at the top of the water heater tank. When it is released through open faucets, it can ignite or explode if exposed to a flame or spark. For example, if the dishwasher is the first fixture you operate after you have been away from the property for a long time, the fixture can become filled with hydrogen. A spark from the electronic controls can cause the appliance to blow up. For this reason, draining your water heater to the exterior is doubly recommended.
Full article at : https://www.washingtonpost.com/archive/realestate/2004/10/23/drain-water-heater-to-avoid-gas-buildup/2efc60c5-6a97-436c-a19c-b673bb34830c/