my sidearm was installed with the cold water entering on one end and the hot water coming out of the sidearms other end is hooked up to the cold water in on top of my oil fired hot water heater,the hot water coming out of the sidearm does not last very long, maybe 30 seconds, is there a way to circulate water through the water heater,or an easy way to remedy this ,seems really inefficient the way it was installed