Killarney is an unincorporated community about three miles north of Oakland, on the way toward the southern shore of Lake Apopka. The properties here are larger and more spread out than in town, with a mix of long-established homes and rural lots, and addresses fall under Orange County for permitting.
Larger lots change the water heater conversation in two ways. Long pipe runs from a well or a meter can affect pressure and how quickly hot water arrives at a fixture, and outbuildings, garages and detached utility structures often hold units that were installed with less supervision than a house would get. Both are worth checking before a fault is blamed on the heater itself.
The same aquifer supply and the same hard water apply, and the Lake Apopka humidity around the north edge of the coverage area is unkind to flue connections, electrical fittings and any steel in an unheated space.