Hot water is coming out of a pipe on the side of the house. This is the relief line from your water heater its purpose is to relieve excess pressure that can build up in your water heater. Several things can cause this excessive pressure or your T&P (temperature and pressure) relief valve may just need to be replaced. This is a condition that should be addressed immediately by a trained professional. Our Benjamin Franklin Plumbers are trained in how to properly diagnose the problem and make the proper repairs.