When running HOT water into unplugged kitchen sink while rinsing dishes the water backs up into the sink - it doesn't happen when using cold water.
Any suggestions?

Are you saying that you can fill one side of the sink with hot water and when you pull the drain it backs up into the other side but you can fill the same side with cold water and it drains fine?

No, what happens is if I have the hot water tap running while rinsing dishes (WITHOUT THE PLUG IN) the water backs up from the drain into the sink but if I have cold water running (WITHOUT THE PLUG IN) the water flows down the drain without any problem,
Also if I have a sink full of warm to hot water for washing up, when I remove the plug it drains very, very slowly but when I tried filling the sink up with just cold water and removed the plug the water drained much quicker.
Weird ah?

Sink drains don't know hot from cold. You must be trying to pull our leg.

NO HONESTLY, I'm not pulling your leg! It really, really is happening as I said - I did say it was weird.
I asked my neighbour and he came up with a possible air lock in the drain but I don't think that would be it or it would happen with both hot and/or cold.

How much soap is involved with this scenario? Hot water tends to make soap more bubbly giving the appearance of slow draining, where as cold water tends to take away the bubbles of the soap and give the illusion of quicker draining. Other than that posability I would have to see this first hand to believe it. Im not saying you are joshing us, just hard to believe without seeing it. You understand our skepticism, yes?

How much soap is involved with this scenario? Hot water tends to make soap more bubbly giving the appearance of slow draining, where as cold water tends to take away the bubbles of the soap and give the illusion of quicker draining. Other than that posability I would have to see this first hand to believe it. Im not saying you are joshing us, just hard to believe without seeing it. You understand our skepticism, yes?

As I'm in Tasmania you probably aren't close by to be able to look for yourself.
I will try using less soap and see what happens, thanks for the suggestion.

How much soap is involved with this scenario? Hot water tends to make soap more bubbly giving the appearance of slow draining, where as cold water tends to take away the bubbles of the soap and give the illusion of quicker draining. Other than that posability I would have to see this first hand to believe it. Im not saying you are joshing us, just hard to believe without seeing it. You understand our skepticism, yes?

Cold water is heavier, maybe it runs down faster!

Cold water is heavier, maybe it runs down faster!



You maybe right about that

I would say either way you must have a partial blockage on the sink drain. I would suggest removing the trap and check things out. If trap is clear, run a snake down the drain beyond the trap and see if you can't get this thing resolved once and for all.

I would say either way you must have a partial blockage on the sink drain. I would suggest removing the trap and check things out. If trap is clear, run a snake down the drain beyond the trap and see if you can't get this thing resolved once and for all.


Thanks for that, I will give it a go :-)

Ira,I figured it out! Research indicates that below the Equator this is a common occurrence since Tasmania is below Australia, closer to the South Pole. The cold water actually tries to go DOWN UNDER but the hot water tries to go up. I live in GA and being fairly close to the Equator we don't have this issue! Hope you come up with a solution. Glad you're a good sport, mate!

Thank you everyone for your suggestions, I have removed the trap & ran snake down drain as suggested earlier & it seems to have fixed the problem.

Nice catch Brain! irageorgeglenn . Thanks for the update and a very interesting complaint. Tom

But Tom, It was I, Lee, that suggested snaking the drain. I only ask for credit where credit is due. LOL.