Cleaning Cold Water Storage Tank

[Youngpup]

Hello. Decided to clean sediment from my cold water storage tank(just sediment nothing else is there). The pipe to the tank also splits off and feeds the hot water systems header tank(which also needs cleaned, but the boiler man can do that one). The water tank has 3 outlets. The overflow, one to the bathroom and one to a hot water cylinder. Basically I plan to close the mains valve in the loft and run the cold taps in the bathroom to drain the tank and then scoop out the remaining water and sediment. I also thought to first run the cold taps and disturb the sediment so it flushes down throught the bathroom pipes while the mains sends in fresh water.

Any potential problems or issue's I should be aware of? I'm a bit concerned of the sediment getting down into the hot water clyinder. Would that be an issue?

 

[steadyon]

1. Provided there is no hot water usage, there will be no flow from the cold water storage cistern into the hot water cylinder, so no transfer of sediment.
2. I wouldn't want the sediment flowing through the cold water pipes, so wouldn't stir it up. Just drain the tank, then shovel / sponge / wipe all the sediment, then refill.

 

[Ben-gee]

Again, don’t stir up the sediment!

I use a wet/dry hoover for this job. Depending on how much play is in connections I wedge something under one side of the tank to get more water out via the cold taps, this means less emptying of hoover.

 

[Ric2013]

One of my favourite tasks. So much so I often end up doing it for free. There's a lesson I need to learn here... Anyway. I have a very nice garden hose in my van. I'd give it to you if I could, but I borrowed it - err, no sorry and with apologies to Syd Barrett too (who writes this twaddle?)

I make sure one end of the hose can drain safely without flooding the house, securing it if necessary. The other (clean) end I take into the loft. Without having any of the outlets draining anything out, I push down on the ballcock float and hold the hose up to the nozzle for 30 seconds or until I can hear the hose start to suck and then I plunge the end of the hose under the water. The hose then acts like a Hoover, as the gravitational flow sets up a siphon in the hose with no electricity required. Probably best not to stir up the sediment as it is generally better to suck it off the bottom, though I must admit to sometimes draining as much as I possibly can, stirring, and then re-draining in order to suck out the remaining solids which are now in suspension: I find I sometimes cannot really clean under the ballcock properly any other way.

The above can be easier than wiping out the cistern when access to the tank for cleaning is poor (surely not!). If you have an isolator on the ballcock, you can use that to control flow into the cistern, or just tie up the float in some way if you don't want to have to go down to the stopcock.

 

[Youngpup]

In the end had the tank emptied by a plumber as i needed another issue looked at. Believe it or not I booked him to clean the tank and other issue and they turned up with a mop to stir the sediment while they drained through the bathroom. I asked why no wet vac or syphon and they went off and got one. Job done.

 

[Ric2013]

.... they turned up with a mop to stir the sediment while they drained through the bathroom....

To be fair, in my own house, I'd probably be happy with it drained through the cold to the bathroom, provided I had washered taps and not ceramic valves or something fancy that could get damaged or clogged by sediment. Quite a few provisos there!

As it is, I have to siphon, because all my cold taps are on mains pressure. Quicker, more effective, and more enjoyable anyway.