Wanting to empty toilet cistern of water without turning off water.

[blocked]

Hi people,

I appreciate I may be wanting the impossible.

I wish to replace the dual flush siphon in a toilet cistern. The toilet is quite old (possible 20 years old) and the siphon looks like it has been in there since then. The toilet has not been flushing properly and I am nearly certain it is the siphon that is broken

I live in an apartment (that may be relevant) and I have turned the main water supply off. The reason I did that was because I can not access any tap to turn off the water going to just the cistern. There may be one, but it may have been enclosed behind a structure (housing) immediately beneath the cistern that seems to be made of wood and his covered in wall tiles. I am not going to tear it apart to see if there is a tap within it.

Despite having turned off the main water supply water is still going into the cistern. Obviously I need to stop water from flowing into the cistern to be able to remove it and replace the siphon. There seems to be a cold water tank (in a closet in the bathroom) and I think that is where the water in the cistern is coming from. Should I simply drain that by leaving the cold water tap on the bath running (can that even happen?)? I've looked for a tap running from the cold water tank to the cistern but I can't find any. There are 2 gate valves connecting the cold water tank to an immersion heater (that information may be of some use).

Help will obviously be appreciated :smile5:.

L.

 

[Dsp]

Check for a valve at the bottom of the fill valve.
What type of fill valve do you have??
Is the fill valve solid piped or flexi??

 

[blocked]

Hey Dsp,

There is no valve at the bottom of the fill valve. I don't know exactly what kind of fill valve is in the cistern but I think it is a solid piped one. I think I will need to stop water from getting anywhere near the cistern never mind into it, as I think I need to detach the cistern.

 

[blocked]

There appears to be no isolating valve between the main water supply and the cistern. Also, I think I am right in assuming, the water going into the cistern seems to be coming from a cold water tank and again there is no obvious of isolating the cistern from that water supply. There may be, I just may not be spotting it or simply don't know where to look.

 

[Dsp]

Yes you need to isolate the water completely to replace the syphon as you will need to remove the cistern from the pan, you may also need a new close couple sealing ring/kit with all the bolts to fasten it back together again,
Where in the country are you as a local member might be able to help you

 

[blocked]

I'm in Belfast.

 

[Dsp]

If there isn't a means of isolation you need one fitting usually by freezing a pipe to fit one

 

[SimonG]

Tie the float valve up in the cistern. Just make sure it stays put when you pull the syphon out. That is if its a low level flush and not close coupled.

 

[blocked]

Can I stop water from getting into the cistern by draining the cold water tank? Is that advisable to do? Can I do that by leaving the cold water tap in the bath running? I've turned the stopcock to off so I assume that if no water is getting from the cold water tank to the pipe leading to the cistern I can go ahead and remove the cistern. I expect to deal with a bit of leftover water coming the pipe but it can't be much. Does that sound plausible?

 

[blocked]

Hi SimonG,

It is close coupled

Thanks though.

 

[Dsp]

Can I stop water from getting into the cistern by draining the cold water tank? Is that advisable to do? Can I do that by leaving the cold water tap in the bath running? I've turned the stopcock to off so I assume that if no water is getting from the cold water tank to the pipe leading to the cistern I can go ahead and remove the cistern. I expect to deal with a bit of leftover water coming the pipe but it can't be much. Does that sound plausible?

Hold the ball valve up in the tank, drain the tank via taps and flushing the toilet if possible and check if water stops entering the toilet if not I think you need a plumber to come take a look

 

[KingDoey]

The easiest way to explain to you is tojust turn both the gate valves off under the cold water tank you mentioned. One of them will be the cold feed to your bathroom.

 

[Ray Stafford]

The easiest way to explain to you is tojust turn both the gate valves off under the cold water tank you mentioned. One of them will be the cold feed to your bathroom.

And with luck, after donkeys years on not being used, at least one of them will still work!

 

[Kndb2915]

Try draining off all the water, isolate mains supply and drain hot and cold through bath ( sounds like your cold fed from tank in loft. Once this is drained completely, cut pipe to cistern and put an isolation valve Iin place. Turn water back on in street (make sure isolation valve is in off position) check ball valve in loft not stuck and this will make it easier to change cistern

 

[kris]

You mentioned u shut the mains off. Do that then drain the tank by opening all the hot outlets.
The 2 gate valves u mentioned one is for the hot water tank and the other might be for the bathroom feed from the storage tank. Or it could be for a shower.