Plumber in Roundup, Apache Junction, AZ

This is the single most valuable thing we can tell a seasonal resident, and it takes about ten minutes.

Shut off the main water supply to the unit — not just the water heater. Open a couple of faucets to relieve residual pressure so nothing is sitting under load for months. Turn the water heater off entirely or to vacation mode; there is no reason to keep a tank hot through an empty summer, and on a small park model heater that is a meaningful cost for nothing.

Drain the water heater if you are away for a long stretch and it is practical, and leave the drain valve open. Pour a little water into every drain before you go so the P-traps are full — and in a unit that will sit unused for months, adding a splash of cooking oil on top slows evaporation dramatically and keeps sewer gas out.

Arrange for someone to check the unit periodically. And for anyone away several months, a smart leak detection device with automatic shutoff is genuinely the highest-value plumbing purchase available — it turns a catastrophic failure in an empty unit into a phone call.

On return, a startup check saves a lot of unpleasant surprises: turn the water on slowly and watch for leaks at every fixture and connection, check under sinks and around the water heater, flush the water heater before putting it back into service if it has sat, and run every drain to refill the traps.

Angle stops are the item most likely to misbehave. Hard water seizes multi-turn compression valves, and a valve that has sat closed for six months sometimes weeps when it is reopened. Replacing them with quarter-turn ball valves is inexpensive and it means they will actually work in an emergency.

On the community side, park properties typically have shared main lines serving many units, and one blockage affects everyone. For park operators and managers, an annual jetting and camera inspection before monsoon season costs a fraction of an emergency call-out with tenants affected — and it is scheduled at a time that suits the property rather than at 9pm in July.