[JRTJH]

If you winterized without closing the bypass valve and you used RV antifreeze in the plumbing lines, then you have RV antifreeze in the water heater. The "pink stuff" is corrosive to the tank lining and will cause problems in years to come. Whether it's 3 years or 13 years is anybody's bet...... I'd urge you, if you used antifreeze, to consider closing the bypass valve and flushing the water heater with fresh water to rinse any antifreeze from the tank.