How to Open Up a Fireplace's Old Gas Pipes

Turn off gas appliances other than your fireplace, such as the gas range, gas furnace and water heater. Attempt to light the fireplace and observe the size of the flame.

A large, steady flame may indicate that your fuel supply system is insufficient for the number of appliances connected to it. In this case, opening up old gas pipes won't solve your fireplace's problems.

Turn off your fireplace and other gas appliances. Close the gas valves on individual appliances, if they're readily accessible.

Shut off the fuel supply to your home at the gas meter by moving the lever on the meter to the "Off" position. Clamp an adjustable wrench on the handle to gain leverage if you can't turn the handle all the way to the "Off" position by hand.

Locate your gas fuel system's purge point, which is a large valve with a lever attached to it near the meter. Turn this lever to the "Open," or "Purge," setting. Wait several minutes for the gas to leave the system, even if you don't hear the gas escaping.

Locate any old valves, which can be identified by metal handles or damaged metal surfaces, between the gas meter and your fireplace. Adjust an adjustable wrench to the size of the valve fitting and unscrew it from the two gas pipes it unites.

Apply a small bead of pipe thread compound to the threaded ends of the pipes, squeezing it directly out of the tubes and onto the threads. Screw in a new ball valve to reattach the gas pipes, using the adjustable wrench.

Examine the gas pipes, looking for any crimped sections of soft copper pipe. Remove these sections with the adjustable wrench and replace them. Avoid trying to straighten or crimp copper pipes that have been damaged, as this may create new gas leaks. Use pipe thread compound on all new connections.

Close the purge valve on your gas fuel system. Turn on the gas at the meter by moving the handle back to its original position.

Prepare a soapy solution of water in a bowl or cup and several drops of liquid dish soap. Spread the soapy water over any joints you serviced to open up the gas pipes. Check for bubbles, which indicate remaining leaks. Shut off the gas supply immediately if you detect leaks.

Open the gas valve on your gas fireplace if you don't detect any leaks. Light the fireplace and wait several seconds for fuel to reach the burner.