Having a leak in a central heating system can be a nightmare to resolve. In general, it's not an easy do it yourself job, but if you have a little experience and someone you can call as a back up, you may be able to correct the situation yourself.
Step 1: Check Your Warranty
If your heating system is still under warranty, call and schedule an appointment. Working on a system that is under warranty can void the warranty.
Step 2: Apply the Leak Sealant
A leak sealant will be a liquid seal that is poured in to piping system. You can find liquid sealant that is made specifically for heating systems. You need to be sure to read the instructions provided carefully. Using too little will render the sealant ineffective, and too much can create clogs in the system.
Step 3: Contact a Professional
Very often having a leak in a heating system will require a pipe to be replaced. This can be a messy job. In some cases the flooring needs to be ripped up to create access to the pipe in question. If the sealant doesn't work it's a good idea to have a professional diagnose the system.