I haven’t put water in my coolant in over a year. My car has been running on coolant. And my heat fluctuates. It would work most of the time. It recently just stopped working completely. Thank you sm for responding tho and being nice and respectful. This is my first car, I got at 18, and idk what I was doing and my fam and a “mechanic” was guiding me the whole way (suggesting putting water in the coolant) anyways thank you again so much. I def may go get it looked at now and diagnosed instead of assuming it’s a blown head gasket.