Making sure I don't cause a flood.

[scubapete]

Hi,

New bathroom again (thanks for all help so far)....

My job for this weekend is to remove asbestos CWC and plumb in a new Aqualisa Axis digital pumped shower.

Below is my airing cupboard:

I'm going to cut the pipe at (A) and replace with new copper from new CWC and replace that gate valve with a lever ball valve.

I'm also going to cut in an equal T at (C) (hot water out from HWC - pipe hidden in photo) and run a pipe to shower pump unit.

Finally, the gate valves with red wheel handles did go to the old power shower which I removed. The cold will come away with my chop at (A) and I intend on cutting out the hot at (B) or at least shortening the branch.

Now notice the drain cock below (A). I can use this to drain the CWC, right? Will it also drain the HWC?

I would prefer to keep the hot water in the HWC. I'm thinking that if I replace pipe to (A) and close the new valve I can cut (B) and (C) without fear of the HWC emptying over my landing. Is this correct?

 

[Bahco]

A looks like the cylinder feed from the tank. You will drain the tank and also the cylinder.

Maybe the pros will prove me wrong.

 

[Breesey]

For a pumped shower you will need a dedicated cold feed from your CWC and a dedicated hot supply from your HWC using either a Surrey or an Essex flange on the HWC. Teeing into the hot distribution pipe coming off the top of the cylinder could cause the pump to cavitate if a hot tap is used else where while the shower is in use.

Cutting the pipe at A will empty both the cold and hot onto your landing, unless you drain these down first!!. Drain the cold through the taps and the hot via that drain off below A.

 

[John M]

CWC = Cold Water Cylinder ?

How comes cylinder & not just plain olde tank .....

Just wondering

 

[Breesey]

CWC = Cold Water Cylinder ?

How comes cylinder & not just plain olde tank .....

Just wondering

Cistern old Chap!

 

[John M]

Cistern old Chap!

Oki .......... Err whats the diff between a Cistern & a Tank ? (Or am I just being St00pid now)

 

[Softus]

CWC = Cold Water Cylinder ?

How comes cylinder & not just plain olde tank .....

Just wondering

The problem with the word "tank" is that many people use it to refer to the cold storage cistern, so it's less ambiguous when referring to the DHW tank to call it a cylinder.

 

[Breesey]

Cistern old Chap!

Oki .......... Err whats the diff between a Cistern & a Tank ? (Or am I just being St00pid now)

Not alot!!

 

[John M]

it's less ambiguous when referring to the DHW tank to call it a cylinder.

But isn't a cylinder called a cylinder cos its well ..... Cylindrical ?

 

[Softus]

Oki .......... Err whats the diff between a Cistern & a Tank ?

Something that is open at the top and filled using a float valve is a cistern.

Something that is entirely enclosing, and capable of being full to the brim, is a tank.

"John M"

it's less ambiguous when referring to the DHW tank to call it a cylinder.

But isn't a cylinder called a cylinder cos its well ..... Cylindrical ?

Your point being...?

 

[John M]

Ahhhhhhhhhhhh Now I geddit

 

[scubapete]

Thanks, saved my new landing carpet! Will fit the Essex flage as suggested.

I thought the HWC would have been air-locked because all the hot taps are turned off. Is it the HWC vent pipe that allows it to empty? Or is it just plain old gravity?

Here's another one:

If I close the gate valve feeding the HWC, I will no longer get hot water out of the taps, right? If I were to then chop the hot pipe just under the bath tap, will I flood the bathroom?

At the very least won't gravity 'equalise' the water in the hot pipe between HWC and bath? i.e. in diagram the contents between A and HWC will come out.

Sorry for the paranoia. I will be fitting service valves everywhere through this project.

 

[Softus]

I thought the HWC would have been air-locked because all the hot taps are turned off. Is it the HWC vent pipe that allows it to empty? Or is it just plain old gravity?

Both.

If I close the gate valve feeding the HWC, I will no longer get hot water out of the taps, right?

You'll get the contents of the vent pipe.

If I were to then chop the hot pipe just under the bath tap, will I flood the bathroom?

Not if you open the tap first and put a drip tray under where you cut the pipe.

At the very least won't gravity 'equalise' the water in the hot pipe between HWC and bath? i.e. in diagram the contents between A and HWC will come out.

Correct.

 

[Thomasthepiperson]

How old was the cold water cylinder? I am just wondering are they all made out of Asbestos? Would my Cold water cylinder contain Asbestos? presumably fitted around 1995 or 1996.

 

[Dextraneous]

The thread is 7 years old