Why is my telemetry (wireless) heart rate reading erratic or non-existent?

"The telemetry (wireless) heart rate system depends on a strong, clear signal being presented from the chest strap transmitter to the receiver inside the equipment console. In order to present a clear signal, you should correctly position the chest strap snugly against your body. (See your Owner’s Manual for details). Moist skin helps the transmitter strap make good contact, so perspiration or even dabbing a bit of water onto your skin may help.
When you first begin using the heart rate strap, lean in close to the equipment console for a few seconds to allow the receiver to pick up the signal. Once the console has a lock on the signal, you can step back to a normal exercise position and begin your workout.
If the equipment has touch heart rate grips, you should not touch them while using the chest strap, as this will override the telemetry heart rate system. If the chest strap is several years old, it is possible that the battery in the strap has died. If this is the case, contact your Precor Authorized Dealer for assistance, or contact Precor Customer Support at 1-800-786-8404.
Finally, wireless heart rate signals are susceptible to outside interference from other wireless signals present in the area. If the readings are erratic, try to identify the sources of interference. Likely items that may cause interference are wireless internet devices, cell phones or cell phone towers, and wireless dog fences."