I appreciate all responses. The information is very helpful. Over the winter I noticed there was pink slush coming from the water heater (outside). Worried that this might be the result of a cracked water heater I went inside the RV, removed the access panel to see if there was any water/antifreeze inside, there was none. The water heater has the drain plug in it still. Do you think it built up pressure in the tank and released through the pressure relief valve? Since the RV is older, I may take it to a RV service center to have it de-winterized, and have the LP gas lines checked out as well as all of the appliances.