15-11-2016, 08:16 PM
I dare-say the expansion of the water in the header tank might've caused some output from its overflow, but that's beside the point. That family had only moved into the rented property that day - in amongst the stress and hassle of unpacking and settling down their children, they can be forgiven for not spotting water flowing from the overflow - assuming any did, and assuming the overflow had been placed in a sensibly conspicuous place.
But the problem occurred because the header tank in the loft - the tank containing all the cold water that feeds into the hot water cylinder - was made of plastic. As most are. The immersion heater stuck on, which led to the water in the tank in the loft heating up, and at some point, that caused the plastic tank to fail catastrophically, releasing all those gallons of stored water in an instant.
Perhaps I am using the term "header tank" incorrectly? I mean the cold water storage tank that provides water (and "head") to the hot water cylinder. Some references suggest that the term "header tank" might refer to the small tank that non-sealed central heating systems used. Either way, it's completely clear from the context from just a perfunctory skim of the news story.
The trouble with immersion heaters is that they can have long service life, especially where the water is "kind" to them, so there must be plenty of 20+ year old ones out there. Certainly, the one that failed was a type that lacked a separate cut-out. I'm not sure what type I have in my DHW cylinder - it must be around 20 years old. We have gas, so it's only for backup. I was glad of it when the boiler failed 5 years ago - it meant that I could take my time deciding how to go about replacing it, rather than just making a "panic buy". During that time, I was monitoring the current it took for safety and energy assessment reasons (I concluded it was cheaper to leave it on 24/7, once I'd satisfied myself it was reliable).
That poor family though. And others, it would appear. The story certainly touched me at the time, with a 2 year old, and another baby on the way.
But the problem occurred because the header tank in the loft - the tank containing all the cold water that feeds into the hot water cylinder - was made of plastic. As most are. The immersion heater stuck on, which led to the water in the tank in the loft heating up, and at some point, that caused the plastic tank to fail catastrophically, releasing all those gallons of stored water in an instant.
Perhaps I am using the term "header tank" incorrectly? I mean the cold water storage tank that provides water (and "head") to the hot water cylinder. Some references suggest that the term "header tank" might refer to the small tank that non-sealed central heating systems used. Either way, it's completely clear from the context from just a perfunctory skim of the news story.
The trouble with immersion heaters is that they can have long service life, especially where the water is "kind" to them, so there must be plenty of 20+ year old ones out there. Certainly, the one that failed was a type that lacked a separate cut-out. I'm not sure what type I have in my DHW cylinder - it must be around 20 years old. We have gas, so it's only for backup. I was glad of it when the boiler failed 5 years ago - it meant that I could take my time deciding how to go about replacing it, rather than just making a "panic buy". During that time, I was monitoring the current it took for safety and energy assessment reasons (I concluded it was cheaper to leave it on 24/7, once I'd satisfied myself it was reliable).
That poor family though. And others, it would appear. The story certainly touched me at the time, with a 2 year old, and another baby on the way.
