There may be a few explanations for this but you must know if the water is raw water from sea or fresh water from the fresh water tank. If it is raw water from the sea and you were cruising for a while the water could have been heated up from the engine compartment. The basic flow is Seacock, multi port strainer (engine, raw water wash down, and head ) all feed of of one seacock. The head flush water is attached to a 1/2" fitting off of the strainer then there is a check valve. The down stream side of the check valve goes to the head. Water is always sitting in this section between the check valve and the head. The engine compartments in Rangers are not very well ventilated and get very warm. I saw temperatures above 160F before installing a full ventilation system in a C26. The water sitting in that hose can heat up over a period of time. The simple check for this is flush 4 or 5 times and then see if the water is now cool. If it is cool there isn't an issue. You will be operating the boat the same as every Ranger tug operates warm engine compartment. If the water remains hot and it is raw water flush???
If it is Fresh water flush you may have two explanations for this. (1) the previous owner taped into the hot water line instead of cold water line for head water flush. Honestly I don't think that is a big problem. If I did that I would leave it that way.
The other issue that could be happening is freshwater flush plumbed to the cold water side pulling hot water from the tank would indicate the hot water tank check valve is leaking by. This would be something that you would want to address if you find that to be the issue.
