Can you provide any pictures or a more detailed description?

I presume these are normal threads and you are trying to turn the wrench counter-clockwise to loosen, right? :-)

It sounds like there may be corrosion involved, which will make it difficult to loosen. It could also be good old-fashioned pipe-dope that is thoroughly set and hardened.

A longer handle on that wrench might help (Archimedes, levers, etc.).

Also, impact can help a lot. Tapping it with a hammer while trying to turn it might do the trick. Or pounding the handle with a hammer in a counter-clockwise direction might do it.

Once you get it to start turning, the rest should be easier.

Of course, depending on your tolerance for replacing part of your plumbing if it breaks, enough raw physical force can solve a surprising number of problems...

I presume these are normal threads and you are trying to turn the wrench counter-clockwise to loosen, right? :-)

It sounds like there may be corrosion involved, which will make it difficult to loosen. It could also be good old-fashioned pipe-dope that is thoroughly set and hardened.

A longer handle on that wrench might help (Archimedes, levers, etc.).

Also, impact can help a lot. Tapping it with a hammer while trying to turn it might do the trick. Or pounding the handle with a hammer in a counter-clockwise direction might do it.

Once you get it to start turning, the rest should be easier.

Of course, depending on your tolerance for replacing part of your plumbing if it breaks, enough raw physical force can solve a surprising number of problems...

Can you provide any pictures or a more detailed description?

I presume these are normal threads and you are trying to turn the wrench counter-clockwise to loosen, right? :-)

It sounds like there may be corrosion involved, which will make it difficult to loosen. It could also be good old-fashioned pipe-dope that is thoroughly set and hardened.

A longer handle on that wrench might help (Archimedes, levers, etc.).

Also, impact can help a lot. Tapping it with a hammer while trying to turn it might do the trick. Or pounding the handle with a hammer in a counter-clockwise direction might do it.

Once you get it to start turning, the rest should be easier.

Of course, depending on your tolerance for replacing part of your plumbing, enough raw physical force can solve a surprising number of problems...

Can you provide any pictures or a more detailed description?

I presume these are normal threads and you are trying to turn the wrench counter-clockwise to loosen, right? :-)

It sounds like there may be corrosion involved, which will make it difficult to loosen. It could also be good old-fashioned pipe-dope that is thoroughly set and hardened.

A longer handle on that wrench might help (Archimedes, levers, etc.).

Also, impact can help a lot. Tapping it with a hammer while trying to turn it might do the trick. Or pounding the handle with a hammer in a counter-clockwise direction might do it.

Once you get it to start turning, the rest should be easier.

Of course, depending on your tolerance for replacing part of your plumbing if it breaks, enough raw physical force can solve a surprising number of problems...