If it's a pinhole leak, use a piece of rubber and a couple hose clamp directly on it. (Can get one from auto parts or hardware store). If the hole is wider, some hardware stores also sell a wider clamp for pipe leaks.

Also, you could just put a bucket under it and leave it alone until the plumber arrives.

Hi thanks for the responses. I have gone ahead and put a bucket underneath, however most of the water is seeping into the surrounding wood rather than falling on the floor. I will look into the hose clamp.

Wrap an old sock/t-shirt/rag around the leak to keep the spray down and lead it to the bucket.

If you know the exact location of the pin hole you can cheaply & easily make a permanent repair yourself and save the cost of a Plumbers service call.

That appears to be a 1/2" copper pipe. Before you start, get a 1/2" copper pipe compression union. (A 5/8" copper tubing union is the same size).

You will need a claw hammer to pull the pipe hanger, a tubing cutter to cut the pipe and either two channel lock pliers, two adjustable wrenches or an adjustble wrench & a pair of pliers. (You need one tool to hold the union steady while tigthening with the other).

Begin by shutting the water off, then drain the system down until there is no water in that pipe. You should be abled to drain at a laundry sink or faucett in the basement or an outside hose bibb.

When the water is drained cut the pipe and install the union where the leak is. Once tightened the union will servie as a code approved permanant repair.

After the union is installed and tightened you can turn the water on again, then go to each faucett in the house and open the faucett to bleed off the air in the line until you get a full flow of water and go to the next faucett. After you bleed the air out the job is done.

Total cost of repair about $5 for the union.