Utilising vented tank when there's no mains water?
Discussion
Our water supply failed last night, second time this year.
A few thousand properties off supply, lift pump to our local reservoir failed. They are now filling the reservoir using tankers.
2 years ago we had a vented hot water tank with a header tank in the loft. This gave us a bit of a buffer. If the cold (mains) taps stopped, we could use the hot taps until the header ran out.
We now have an unvented tank, so the hot taps stop working when the mains goes off.
Is there any sensible way of accessing the 210 litres of water in the tank?
A few thousand properties off supply, lift pump to our local reservoir failed. They are now filling the reservoir using tankers.
2 years ago we had a vented hot water tank with a header tank in the loft. This gave us a bit of a buffer. If the cold (mains) taps stopped, we could use the hot taps until the header ran out.
We now have an unvented tank, so the hot taps stop working when the mains goes off.
Is there any sensible way of accessing the 210 litres of water in the tank?
Never tried it, but I'd turn off the cold supply and disable the heating, then open some hot taps so air can flow into the tank, then open the drain valve at the bottom of the tank to let water out. I.e. I'd follow the process for draining an unvented cylinder as if I were going to do some plumbing.
Not really imo... If you put a pumped cold buffer tank in you risk burning out the pump on that when it runs dry and if you put a bleed point in on the cold feed to the unvented cylinder so you can 'unairlock' it you do have a risks of possibly vaccume collapsing it while effectively draining it which will rely on gravity and the cylinder might be to low for any outlets to get much anyway - if the unvented is way up in the loft where all the outlets in the house could work the risk of vaccume collapse becomes greater.
Sounds like a fair bit of messing around, with the risk of leaks.
We are in a bungalow, unvented tank in the integral garage, so very little head.
Probably makes more sense to keep a case of bottled water in the cupboard, plus a few 25 litre containers filled with tap water for toilet flushing etc.
SWW did a pretty good job of getting everything working again, just a bit surprised that they don't monitor the lift pump or reservoir level, so they were seemingly unaware until the system ran dry and customers started complaining.
We are in a bungalow, unvented tank in the integral garage, so very little head.
Probably makes more sense to keep a case of bottled water in the cupboard, plus a few 25 litre containers filled with tap water for toilet flushing etc.
SWW did a pretty good job of getting everything working again, just a bit surprised that they don't monitor the lift pump or reservoir level, so they were seemingly unaware until the system ran dry and customers started complaining.
I think getting a pressurised system must jinx the local water supply - counting back the blocks of text alerts we've had, our water has been off 8 times since we switched, including for a few hours last week.
We quickly got into the habit of making sure the kettle is full before going to bed.
We quickly got into the habit of making sure the kettle is full before going to bed.
Simpo Two said:
If only they'd built houses with big tanks of water in the roof. Oh hang on...
The one on my parents between-the-wars house was huge - set in a massive lead-lined drip tray with its own drain (which came in handy when the tank started weeping). It ran the toilet cisterns (but they took ages to refill) and all the taps apart from the cold in the kitchen. Apparently they were sized to run the house for 2 days.Richard-D said:
Simpo Two said:
If only they'd built houses with big tanks of water in the roof. Oh hang on...
There are down sides to that system too. In my previous house I decided that I didn't want a huge asbestos tank with dead mice in it connected to my taps. Have been progressively removing them from our properties ever since. Water pipes in uninsulated spaces just doesn’t seem like a good idea.
Why do heatpump installers seem to want to switch to unvented tanks?
I appreciate that an old vented tank will have a smaller coil, not really suitable for the lower flow temperature of a normal 55 degree heatpump, but why the reluctance to plumb a new unvented tank from an existing gravity feed?
Obviously unvented can give better flow rate for taps and showers, assuming decent mains pressure and flow rate, and it's probably healthier with no dead animals/birds in the header.
Plenty of downsides though, like no reserve, more potential failure points, stringent maintenance requirements, plumbers need more qualifications, etc.
I appreciate that an old vented tank will have a smaller coil, not really suitable for the lower flow temperature of a normal 55 degree heatpump, but why the reluctance to plumb a new unvented tank from an existing gravity feed?
Obviously unvented can give better flow rate for taps and showers, assuming decent mains pressure and flow rate, and it's probably healthier with no dead animals/birds in the header.
Plenty of downsides though, like no reserve, more potential failure points, stringent maintenance requirements, plumbers need more qualifications, etc.
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