Wayward Aqua stat?

John Penwarden_2

I have a 7 yr old Crown indirect water heater (Super-Stor) 30 gal, mated to a Crown Freeport oil-fired boiler. REcently I noticed that the hot water was very hot (I upped the temp on aquastat to 170 to clean some equipment, then turned it back down to 120). The wife said it was still too hot, so I turned it down to 110, still too hot, so I pour a glass of hot water and put a thermometer in it. It reads 130. I turn the aquastat down even more (guessing around 100, it's not calibrated that low). Still reads 130. Would this be an aquastat problem? should I just look at the zone valve first (Automag). Any help is greatly appreciated.