# Tank full but no cold water



## Peckham (12 Nov 2010)

For some reason I'm not getting any cold water through bathroom taps, nor is the toilet cistern filling. I've plenty of hot water, and when I use the hot water I can hear the tank refilling to replace the water used.

Any idea what might be going on. I came back from 10 day holiday yesterday, and it may be the case that the problem happened whilst I was away and I've only now drained the tank of cold water.


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## Brendan Burgess (12 Nov 2010)

I had a similar problem and a neighbour had a look at it.

He said it was an airlock. He turned on the cold tap full, but put the palm of his hand over it to form a complete seal. after a few minutes the water came gushing out.


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## Peckham (12 Nov 2010)

Thanks Brendan. 

Did he turn both taps on and form a seal around the working tap? I read this somewhere else, but it doesn't seem to be working for me.


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## Peckham (12 Nov 2010)

Update: Tried this using the mixer tap on the bath - i.e. turning on both the hot and cold taps on the bath, and the cold tap in the sink. After a few seconds hot water comes out of the cold tap in the sink (and the toilet cistern fills), but as soon as I take my hand off the mixer tap in the bath, the flow from the sink tap stops.


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## SparkRite (12 Nov 2010)

Peckham said:


> Thanks Brendan.
> 
> Did he turn both taps on and form a seal around the working tap? I read this somewhere else, but it doesn't seem to be working for me.



The method Brendan has outlined will only work where you have an airlock in your hot water circuit and you use a mixer tap downstairs to force the mains fed cold back through the hot circuit to force any air out.

If you wish you can use a length of hosepipe to connect the mains fed cold to any tank fed cold tap (preferably one downstairs) and try to back feed the system to remove any airlock.


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## SparkRite (12 Nov 2010)

Peckham said:


> Update: Tried this using the mixer tap on the bath - i.e. turning on both the hot and cold taps on the bath, and the cold tap in the sink. After a few seconds hot water comes out of the cold tap in the sink (and the toilet cistern fills), but as soon as I take my hand off the mixer tap in the bath, the flow from the sink tap stops.



All you have done here is form a "local loop" and have not forced any water/air anywhere.

You need to do as I have said in above post with all taps off except the ones that are attached to the hose and you should hear the air being expelled in the header tank.


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## Peckham (12 Nov 2010)

Cheers SparkRite - am going to try this in a few minutes


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## Peckham (12 Nov 2010)

Tried that. Doesn't seem to have worked.

Water went back through the system. I could hear the toilet cistern filling, but as soon as I took the pipe away, the flow of water stopped.


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## SparkRite (12 Nov 2010)

Peckham said:


> For some reason I'm not getting any cold water through bathroom taps, nor is the toilet cistern filling. I've plenty of hot water, and when I use the hot water I can hear the tank refilling to replace the water used.
> 
> Any idea what might be going on. I came back from 10 day holiday yesterday, and it may be the case that the problem happened whilst I was away and I've only now drained the tank of cold water.




Ok I have just re-read your first post, is the header tank re-filling (full)  or is it empty??

Did you by any chance turn off any stop cocks in your hot press before you went away?


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## Peckham (12 Nov 2010)

It refills. When I turn the hot taps on, I can hear water going into the tank to replace what I've used and then stopping once it has (presumably) refilled.


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## Peckham (12 Nov 2010)

Have checked the stop cocks - they seem fine (but I'm no expert)


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## SparkRite (12 Nov 2010)

Ok when you used the hosepipe did you let the toilet cistern fill up which would then close the ballcock valve and then force the water to back feed all the way up to the tank?

This step is important.


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## Peckham (12 Nov 2010)

Not sure. Will try again.

(thanks for your help - hugely appreciate it)


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## Peckham (12 Nov 2010)

Tried it again - left it running for a few minutes. Toilet cistern filled up completely, but water kept coming into cistern (presumably due to pressure in system). I also noted that water was dripping from the hose that is connected to the shower.

However, it doesn't seem to have solved the problem.


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## SparkRite (12 Nov 2010)

Very unlikely to be an air lock so.
Would strongly suspect a closed stopcock on the cold feed, probably in the hot press, just make sure all are open coming from the header tank.

Going out now so can't reply for a while.


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## villa 1 (12 Nov 2010)

There may be an airlock/blockage in the cold distribution pipe between the cold water storage tank and the hot press area. Sometimes the only way to clear stubborn airlocks is to connect higher pressure mains supplies to blow out airlocks/debris.
You might try this, but it may be awkward
1. Connect garden hose to mains-outside tap
2. Bring this hose into the attic and try push the end of this hose down the pipe that exits the tank and travels down to the hot press bathroom area(cold distribution)
3. Turn on the outside tap which will in turn send high pressure water down this pipe and clear the blockage. 
Mice have a habit of drowning in these tanks and ultimately the little darlings block cold water supplies
If the supply pipe is a plastic type check for kinks etc, that may lead to poor flow/blockages.


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## Peckham (13 Nov 2010)

Just to update on this....

Had a plumber in this morning. Turns out their was a blockage in the pump which he cleared and all is fine now. Blockage was a build-up of silt over time, and I suppose the water pressure had been dropping over the last while.

Thanks everyone for your help and advice (particularly SparkRite with your speedy responses yesterday).


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## SparkRite (13 Nov 2010)

No problem Peckam, all part of the service. Glad to hear you're sorted.

I can only assume you didn't know it was a pumped system or you would have mentioned it.

Thanks for the thanks.


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