Leak in toilet

EC12345

I wonder if anyone can help. Our downstairs toilet leaks ever ever so slightly when our washing machine (downstairs in the kitchen) is turned on. It drips from the back of the cistern. Any ideas. If you need more info, just ask.

Thanks.

bobthedambuilder

You don't say where exactly where the leak is coming from. Is it dripping from the water feed pipe into the cistern, or from the overflow pipe?

EC12345

Hello, thanks for the reply. It is very strange. It is coming from the back of the cistern and then just drops down the tiles onto the floor. We had a plumber come out last week but he couldn't tell where it was coming from. He said the toilet wasn't leaking. It just happens when we turn the washing machine on.

ormus

it maybe just condensation. combination of fresh cold water in the pipes and higher temps due to the WM being on.

EC12345

Thank you Ormus. That is what our plumber said. Do you think that it has anything to do with the cold weather as well?

Thank you for you help. I am a lady and worry about these things!!

bobthedambuilder

EC12345 wrote: »

Hello, thanks for the reply. It is very strange. It is coming from the back of the cistern and then just drops down the tiles onto the floor. We had a plumber come out last week but he couldn't tell where it was coming from. He said the toilet wasn't leaking. It just happens when we turn the washing machine on.

The reason I asked about pipework is that there is an off-chance that if the washing machine and cistern are on the same run of cold water pipework, turning on the washing machine might cause slight movement in the cistern feed pipe (water hammer), which could eventually loosen a connection slightly.

Having said that, both feed pipe and overflow pipes in most cisterns are usually on the side. You say you're getting a leak at the back, and it's running down the tiles. Is it possible that it's coming from the connection between the bottom of the cistern and the toilet bowl? if the cistern is not firmly fixed to the wall, or the connection to the bowl is a bit dodgy, the water hammer I described above could just be moving the cistern a little bit, which is allowing water to escape.

Try these measures:
1. Wrap a tissue around the cistern / bowl connection and see if it's wet after your next washing machine use.
2. Make sure the cistern fixings to the wall are tight.
3. See if you can feel any movement in the cistern supply pipe when the washing machine turns on. If so, it could indicate water hammer. There's a possible simple fix to this by part closing the main stopcock on the cold water feed into the house (to reduce the pressure a bit). Otherwise speak to your plumber about installing an air chamber or pressure reducing valve into your system.

bobthedambuilder

ormus wrote: »

it maybe just condensation. combination of fresh cold water in the pipes and higher temps due to the WM being on.

This is also a possibility - I've seen this before in my downstairs toilet. But this isn't usually associated with another appliance being turned on elsewhere in the house - it would generally happen when cold water introduced into the cistern causes a condensation on the outside of the cistern from a warmer humid atmosphere in the toilet. It's more likely to happen in the winter than the summer (colder water / heated atmosphere).

EC12345

bobthedambuilder wrote: »

The reason I asked about pipework is that there is an off-chance that if the washing machine and cistern are on the same run of cold water pipework, turning on the washing machine might cause slight movement in the cistern feed pipe (water hammer), which could eventually loosen a connection slightly.

Having said that, both feed pipe and overflow pipes in most cisterns are usually on the side. You say you're getting a leak at the back, and it's running down the tiles. Is it possible that it's coming from the connection between the bottom of the cistern and the toilet bowl? if the cistern is not firmly fixed to the wall, or the connection to the bowl is a bit dodgy, the water hammer I described above could just be moving the cistern a little bit, which is allowing water to escape.

Try these measures:
1. Wrap a tissue around the cistern / bowl connection and see if it's wet after your next washing machine use.
2. Make sure the cistern fixings to the wall are tight.
3. See if you can feel any movement in the cistern supply pipe when the washing machine turns on. If so, it could indicate water hammer. There's a possible simple fix to this by part closing the main stopcock on the cold water feed into the house (to reduce the pressure a bit). Otherwise speak to your plumber about installing an air chamber or pressure reducing valve into your system.

Thank you for this answer. The leak is coming from the bottom of the cistern. It is coming from the back of the cistern and just running down the tiles (when I say running, I mean dripping). It is really hard to explain when I'm not sure what all the toilet bits are called so I apologise. Where the water drips down, it falls nowhere near where any of the toilet connections are. Just out of interest, where is the cistern supply pipe.

ormus

this is the basic principle.
you need to remove one of the factors to stop it.
not always easy.

bobthedambuilder

EC12345 wrote: »

Thank you for this answer. The leak is coming from the bottom of the cistern. It is coming from the back of the cistern and just running down the tiles (when I say running, I mean dripping). It is really hard to explain when I'm not sure what all the toilet bits are called so I apologise. Where the water drips down, it falls nowhere near where any of the toilet connections are. Just out of interest, where is the cistern supply pipe.

You would normally see it connecting into the side of the cistern, although it can also be introduced into the bottom of the cistern. It would normally be a 15mm copper or plastic pipe. if you take the cistern top off and flush the toilet, you will see where the water comes in.

EC12345

I don't even understand that picture

We have lived in this house for eight years. I mean it could have been doing it for that long. We hardly ever use our downstairs toilet (I like to keep it clean!!!) - sometimes I just open the door to poke my head round to check everything is clean - it could have been doing this for years and I haven't noticed!!