Mrjayy

Hi guys, New here and a new owner of an octavia estate 1.9 tdi 2006. So I've just bought the car never owned a skoda before and after some advice. So first of all I've got no heat inside the car, checked coolant slightly low but nowhere near empty so topped up while engine was cold. Left the car running untill it reached temp still no heat. Checked oil and water no water in oil no oil in water, checked matrix one side hot one side cold. Gave the car some throttle noticed steam from expansion bottle then noticed very very small hole in the top edge of the tank, when on the throttle small amounts of water are spitting from the hole along with the steam, water looks brown/rusty. no idea if this hole is supposed to be there... Steam blow off hole? Seen a lot of threads about head gasket and now very worried I've bought a ringer. No other obvious leaks that I can see. Hoping someone is going to tell me it's not necessarily the head gasket. Appreciate all feedback Thanks in advance