Need to replace tap washer - no isolation valve

[St23]

I need to replace the tap washer on my hot tap in my utility room. Unfortunately there is no isolation valve on the pipework.

My hot water supply comes from copper cylinder in bathroom airing cupboard and this is fed from plastic cold water storage tank in the loft.

There are various red wheels in the bathroom airing cupboard. Do I need to turn one of these or do I need to drain the water from the copper cylinder, but then how woulld I stop it from getting re-filled from the loft tank?

I've heard people mention isolation valves next to the tank in the loft. Don't know if I have these.

Can anyone advise me on what to do?

 

[Burnerman]

The cold water from the loft tank enters the copper cylinder at the lowest connection......22mm it should be. If you can find one of your wheel valves on that pipe run, closing it off will stop water entering, and hence leaving, the copper cylinder.
Sometimes......the wheel valves are too tight to turn, sometimes they don't stop the flow completely, and occasionally they can leak from the gland afterwards but its worth giving it a go.
John

 

[I Like Sleeping]

Be careful with gate valves, if they're old they might not turn back on again. If unsure turn the water off at the main stop tap and turn on all the hot water taps until they stop running. You may want to open up a cold tap first to ensure that the mains have isolated correctly.

 

[dcawkwell]

Just tie up the ball valve in the cold tank above open
the hot tap until that thank drains.
You can now chance your tap washer.

 

[St23]

Just tie up the ball valve in the cold tank above open
the hot tap until that thank drains.
You can now chance your tap washer.

So this means that both the copper cylinder in bathroom will empty and also the loft tank.

Might have got this wrong, but I am sure I once read somewhere about tanks collapsing when empty?????

 

[Johnmelad]

Might have got this wrong, but I am sure I once read somewhere about tanks collapsing when empty?????

 

[Dan Robinson]

No - hot water cylinders fill from the bottom and discharge from the top.

It will be fine as long as it isn't something horrid like a Primatic.

 

[St23]

No - hot water cylinders fill from the bottom and discharge from the top.

It will be fine as long as it isn't something horrid like a Primatic.

So, do I have to leave the hot tap open until the copper cylinder is empty?

 

[Dan Robinson]

No. The cylinder isn't going to empty. Just wait until the water stops.

 

[St23]

Why won't the copper tank empty?

As long as the hot tap is turned on and water is coming out of the tap, well this is emptying the copper cylinder.

Please feel free to elaborate if I seem to be missing something.

 

[Burnerman]

The hot water will continue to flow until the header tank in the loft empties - the copper cylinder remains full.
John

 

[Dan Robinson]

Water goes into the bottom of the cylinder and comes out of the top to the taps.

Turn the water off to the cylinder and it will not fill, thus water will stop coming out of the top.

 

[Armo74]

As already said the cylinder discharges water from the top because the cold coming down from the CWSC enters the bottom of the cylinder and forces the hot out the top whilst replenishing the hot water that was in the cylinder with cold. If there is no cold water in the CWSC then there is nothing to force the hot water out but the cylinder will still be full because of the water from the CWSC. The only way to get rid of that water is to drain the cylinder.

 

[St23]

I seem to have had quite a bit of advice - unfortunately you don't all seem to give the same advice.

Please could someone tell me. in very simple terms, and in a step by step fashioon, what I need to do and which cylinder or tank (or both) will need to be emptied.

 

[HERTS P&D]

Turn off your incoming mains to the property
Open cold kitchen tap to check water has stopped.
Open hot and cold bath taps
One water has stopped flowing change the faulty washer and fit an isolator
Close all taps
Open incoming mains
Wait 10 minutes and open taps to remove any air.

Job done!

Andy