When I think about the costs of owning a home and renting it out, two big things always come to mind: Roofs and HVAC systems. They're very different systems on the surface, one protects your home from rain, the other cools and heats it. However, they're very similar in other ways.
Both roofs and HVAC systems cost between $5,000 and $6,000 to replace, making them the largest costs you can incur. That is why preventative maintenance is critical to lowering your long term costs.
On a 10 year HVAC system that costs $6,000 to replace, you can divide out 6,000 by 10 to get $600 a year. However, if you spend $75 a year to have the coils cleaned, the system maintained, and all systems checked, you can make that system last 15 years. Then, your system runs $400 a year ($6,000/15). Every year that HVAC system lasts saves you money, even with the $75 cleaning fee.
Another great example is something I ran into recently. During the annual servicing of a unit that was about 12 years old, the tech found a particular part that was about to break any day. He replaced it for $40, with no additional charges. That one part replacement saved us a $75 trip charge from an HVAC company, or, if it had happened on a weekend or evening, an overtime charge. It also made that tenant very happy since her HVAC was being taken care of, and she never had the heartburn of having it go out.
On the roof side of things, I recommend having the roof serviced every two to three years. This includes blowing leaves off, hammering down any nails, re-caulking around vents, and checking the flashing. This alone gets more years out of your roof and can prevent costly leaks.
Although some owners are hesitant to spend $75 or $100 on a roof maintenance or HVAC servicing, its important to remember that long term, this saves money. Remember the old saying, an ounce of prevention is worth a pound of cure.