I woke up to my carbon monoxide alarm buzzing. I went straight to the boiler cupboard, silenced it, opened every single window in the house, switched off the boiler and called an engineer. The air felt heavy. Stuffy. Two days before the alarm, I’d had a gas engineer round because the boiler had stopped working. He spent two days on it, on the phone with the manufacturer in Scotland, trying different fixes and picking up parts that were a 90 minute round trip. He found the heat exchanger completely clogged. Full disclosure, I hadn’t serviced the boiler in years as I’m planning to replace it with a heat pump. He fixed it and went on his merry way. When I called him about the alarm, he seemed pretty relaxed. Opened the boiler up, had a look, then said: “Oh sorry, I left an inspection flue open. Totally my fault. But don’t worry, it won’t be that much carbon monoxide.” Not that much. I’d had a leak for over two days. Presumably low enough not to trigger the alarm immediately, but still there. Needless to say, this stuff is serious. Gas boilers have served us well, but moments like this make you question how comfortable we should be having them running inside our homes. Four things this made me think about: 1. Boilers can still be dangerous 2. Servicing probably shouldn’t be optional if the consequences can be this severe 3. Repairs are often trial and error, not all boilers diagnose issues clearly 4. Glad I had a CO alarm already in the house We legally require MOTs for cars before we’re allowed on the road. We should have to do the same for our homes.