Blocked cold water pipe?

[Rabbitgirl]

just had a reread, I reckon its air locking.

That would explain why forcing mains through sorts the problem temporarily wouldn't it. But how can I get rid of the problem? I can't do the mains pressure thing on my own so end up with no bathroom until my husband comes home to help me sort it out and we are having to do it more and more often (and boy does it make an unholy mess!)

What causes airlocks?

 

[picasso]

your pipe work is dragging in air (shower pump perhaps ?)and causing the cold feed to the bathroom to airlock, when you put water back up the pipes your clearing the air not a blockage.

 

[Rabbitgirl]

your pipe work is dragging in air (shower pump perhaps ?)and causing the cold feed to the bathroom to airlock, when you put water back up the pipes your clearing the air not a blockage.

Great real time replies fantastic Thanks.

The pipe work where I am getting the blockage is literally just a pipe from the tank to the bathroom where it is then split to the basin, bath and toilet. The shower pump is on a totally separate line from the tank so I don't think it can be dragging air from there.

A new piece of information that I didn't have before. Daughter has just told me that the night before the water stopped this time the toilet cistern was running - would that have dragged in air? But the toilet is the last point in the chain.....

any other ways of air getting in?

 

[Rabbitgirl]

Also no knocking at all in the system, do you usally get knocking with airlocks or not necessarily?

 

[Rabbitgirl]

Right off to DIY store/plumbers merchants to see if we can find a good way of fitting hose (on mains pressure) to one of the taps or the toilet cistern feed (easy to get at and remove from the cistern) so that we can do the mains pressure thing again (at least we'll get the bathroom back if temporarily) without soaking the room.

Still interested in all your help and will be back

 

[picasso]

how big is the tank in the loft and do you know how powerful your shower pump is ? it might be worth running the shower and a tap in the bathroom and see if the level in the tank drops below the take off for the bathroom.

 

[Rabbitgirl]

how big is the tank in the loft and do you know how powerful your shower pump is ? it might be worth running the shower and a tap in the bathroom and see if the level in the tank drops below the take off for the bathroom.

Thanks. Checkeds that. After 20 minutes of running the shower the level in the tank dropped by about a quarter of it's capacity. Still well above the take off for the bathroom. The shower take off is actually marginally higher than the other two take offs - one to bathroom, one to hot water tank. The tank is purposely over the recommended size for the system we have.

Off to DIY store. Back shortly.

 

[Rabbitgirl]

Thanks guys (assumptions being made ) for your help. We put an appliance tee into the system just before the toilet cistern which we can now attached our hose to without soaking all parties involved and will make the job quicker if we have to do it again. We had stopped the mains fill to the tank when we all showered this morning so that we had plenty of room for when we sent water back up the system. We have now refilled the tank via the bathroom. Must say no gunk appeared in the tank and only a few little airbubbles as the the hose was turned on BUT the water is running again in the bathroom. At least we now have an easy point to attach the hose if it needs doing again.

In the long run we may attach all bathroom cold to the mains (not a tricky job as the mains pipe comes up to in the far corner of the room and crosses the floor into the airing cupboard before going up to the tank in the loft). Before we had the bathroom replaced the toilet and basin were mains fed (speed in the cistern and potable water in the basin) but the plumber who replaced the bathroom said we shouldn't have it mains fed as it causes more limescale build up The toilet and basin in the loft extension are mains fed and they never cause us any problems

Anyway thanks very much for putting up with a plumbing novice and for your help.

 

[Agile]

It may be an air lock but can also be caused by other things too.

A favourite is bits of loft insulation in the water and that usually happens with a loft tank without a lid.

A rare and difficult cause is a cut plastic disc which forces itself to fully block the pipe but otherwise is side on and has little effect.

I find its most often just before the gate valve on the outlet of the tank so easy to reach.

One plumber I sent out found a ( dead ) mouse jamming the pipe just before that valve!

Tony

 

[Rabbitgirl]

It may be an air lock but can also be caused by other things too.

A favourite is bits of loft insulation in the water and that usually happens with a loft tank without a lid.

A rare and difficult cause is a cut plastic disc which forces itself to fully block the pipe but otherwise is side on and has little effect.

I find its most often just before the gate valve on the outlet of the tank so easy to reach.

One plumber I sent out found a ( dead ) mouse jamming the pipe just before that valve!

Tony

I am praying that mice aren't involved

We had a feel around the gate valve but it all seemed okay. Your suggestion of a piece of plastic was what were thinking as we would solve it for a while then suddenly, we'd turn on a tap and.... nothing!!!

The other thing is that some of the system is on galvanised pipe and I know that can be prone to mineral build up but all three outlets have some galvanised pipe and it is only the bathroom that seems to suffer.

Oh well, fingers crossed that the good long (took 20 minutes to fill the tank) flow of mains pressure through the system will have cleared any air/plastic/dead rodents out of the system.

 

[Agile]

I had an amusing cause of a similar ilk!

British Gas had replaced the pump on a Puma boiler. Almost as soon as it started it made an almighty noise and BG refused to do any more work on it.

I was called. I discovered the BG man had dropped a part from the old pump down the pipe. As soon as the boiler started the part came up the pipe and jammed into the moving pump impeller. When it was turned off the part dropped out of sight back down the pipe.

Tony

 

[dreadnoughtheating]

Could be a bit of debris 'bobbing about' (thats a highly technical plumbers only term....) in the top of your hot-water cylinder, covering the outlet at the top on occasion, I have found ping-pong balls (sabotage at factory/storage depot wherever) pieces of foam insulation from cylinder etc causing this.

You may wish to consider removal of the top outlet connector to see if you can find an obstruction.

Just my two old pennies worth.

DH

 

[picasso]

as this thread is called "blocked cold water pipe" its fairly unlikely the hot water cylinder is the fault.

 

[Agile]

I have found ping-pong balls (sabotage at factory/storage depot wherever) pieces of foam insulation from cylinder etc causing this.

DH

Much more likely to be an installer having some fun by putting the ping pong ball in through the immersion boss!

I always look inside before I fit them!

But why would that affect the cold water supply?

 

[bengasman]

as this thread is called "blocked cold water pipe" its fairly unlikely the hot water cylinder is the fault.

We do like the old understatement. Or should I call that: moderately mature?