blocked pipe

[neiloneil]

I looked at my sister’s header tank today (the large 40 gallon one), as water has been flowing from the overflow. The insulating jacket was wrapped up with the ball cock (hence the overflowing) and the tank is half full with the fiberglass filling material, which has emptied out of the jacket. I figure maybe some creature has fallen into the uncovered tank and clawed the insulation into the tank while trying to get out.

I decided to drain the tank so I could clear the debris.
I turned off the main stopcock. The kitchen tap instantly lost pressure (which I expected), but so did 2 toilets and two basins. I presume they are also fed from the mains.

The bath tap flowed for say 15 to 20 seconds reducing to a trickle. I think the stirred up debris has now clogged the pipe as only a trickle still emerges after turning the stopcock back on.


My question is

how should I go about draining the tank and clearing the blockage?

 

[TicklyT]

Roll your sleeves up, and have a feel around the outlet at the bottom of the tank, removing any debris you find.

Connecting a hose between a cold and hot tap, and running some mains pressure cold back into the hot system may help dislodge anything already drawn into the tank outlet.

Pinch a colander from the kitchen, and drop it over the tank outlet to help prevent a repeat episode whilst you drain the tank.

Syphon the tank using a garden hose.

Fit a proper cover to the tank to support the insulation jacket.
Pieces of MDF, chipboard, hardboard etc. will always turn into something resembling soggy wheetabix, and collapse into the tank eventually.