Keeping a rental property warm in winter and cool in summer is essential for the renters who live there, but keeping the temperature stable also benefits the heating, ventilation, and air conditioning system, otherwise known as the HVAC unit.

That’s because the HVAC system can suffer damage from extremely high or low temperatures as well as moisture buildup caused by a lack of ventilation.

Learn the basics about HVAC systems, so landlords and renters can better understand not only who’s responsible for heating and cooling in a rental, but who should take care of maintenance and provide repairs.

Definitions

“H” is for “heat”

The implied warrant of habitability requires landlords to supply some method of heat, and some communities get specific about heating requirements.

For example, New York City requires heating units to maintain a minimum temperature of 55 degrees Fahrenheit from October 31 to May 31, and San Francisco requires a minimum temperature of 68 degrees between the hours of 5 a.m. to 11 a.m. and from 3 p.m. to 10 p.m. all year.

Maine requires a minimum indoor temperature of 68 degrees when the outside temperature falls below 20 degrees. Landlords should know their state’s laws regarding heating and cooling.

“V” is for ventilation

The “V” in HVAC doesn’t always get the attention it deserves. Central heating and cooling systems provide automatic air circulation, but rentals that rely on room heaters and lack air circulation systems may suffer the effects the stale air. These include paint deterioration, wood rot, pest infestations, and mold.

Ceiling fans and room fans can provide the circulation needed to control moisture and keep renters comfortable. You also need to maintain them unless otherwise specified in the lease agreement.

“AC” is for air conditioning

In most states, landlords don’t have the same responsibility to provide air conditioning. If you rent a unit with air conditioning, though, you might be under a contractual responsibility to maintain it. If you don’t, your renter may be entitled to a rent reduction or some other consideration.

Common HVAC maintenance issues

Whether the heat in a rental unit comes from a forced air furnace, a heat pump, or a radiant heat system, there are usually two main maintenance concerns. One is the heating unit itself—which includes the heat source and the blowers—and the other is the control network. An air conditioning system, which is essentially a refrigeration system, also has a control network and it’s often the same one that controls the heating system.

Thermostat

Blowers, burners, heating elements, and refrigeration coils can all malfunction, and when they do, the landlord has to repair or replace them. Many HVAC problems, however, result from the thermostat, which can easily be maintained by renters.

Batteries

If the batteries in the thermostat are weak, the heating/cooling system won’t get the message to turn on. Batteries are easy to replace, and renters can do that themselves, especially if they have the manual.

Programming

Failure to program the thermostat properly is such a common occurrence that many appliance repair specialists address it first. Is the thermostat switch properly selected for heating or cooling? Is the target temperature properly selected? Is the unit even on? Renters should have a copy of the manual so they can check the settings themselves before calling for help.

Location

Persistent failure of the central air system to maintain the target temperature could be caused by a poor thermostat location. It may be in the sun, behind a bookshelf, or in the path of a draft. Moving the thermostat, as well as replacing worn wires, is usually a major job.

Cleaning

Thermostat leads can get dusty, and all it takes is a blast of compressed air to clean them. Accessing the leads means removing the cover, which renters can do if they have the manual to guide them.

Filters

The heating and cooling system connects to the living space via a network of metal ducts, and if you’ve ever looked inside one of these ducts, you’ll appreciate the need for filters. When dust enters the ducts and gets drawn into the central system, it can block gas orifices, hinder fan rotation, reduce heating and cooling efficiency, and even potentially create a fire hazard.

Many HVAC pros offer duct cleaning services, but you generally need these only if you’re renovating; if animals, mold, or contaminants got sucked into the ducts; or if someone in the house has become ill. In most cases, however, you just need to service the filters.

Changing the filters at least once a year, which is the best way to maintain system efficiency, is another job that renters can do, especially if you supply the filters. Filters are classified according to their Minimum efficiency reporting value (MERV) rating. The higher the MERV rating, the more efficient the filter.

Filters with high MERV ratings can filter out contaminants as small as bacteria, but they also restrict airflow, so it’s best to stick with a filter with a rating in the range of 5 to 8. Ratings go as high as 16, so 5-to-8 is on the low side of average.

Two ways to approach maintenance

The HVAC system, like the rental unit itself, belongs to the landlord who has a vested interest in keeping it in good condition. As the beneficiary of clean, conditioned air from a properly functioning system, the renter also has an interest in keeping things in working order. Landlords can retain full responsibility for maintaining the system or they can share that responsibility with their renter. Consider adding these details to the lease.

1. Landlord controlled and renter maintained

The renter pays for filters and minor service calls, such as cleaning and minor malfunctions, while landlords pay for major service. In this case, the renter typically pays the utility bills. This can be a good arrangement for sensitive renters who require enhanced air filtration or indoor temperatures outside normal ranges.

2. Landlord controlled and maintained

The landlord assumes full responsibility for maintenance. The lease usually specifies standard hours for maintenance, such as 9 a.m. to 6 p.m., Monday through Friday. If maintenance is required at other times, there could be an extra charge. This arrangement is typical in multi-unit dwellings.

Keep repair records

It’s in everyone’s best interest to maintain a rental property’s HVAC system, and a bulk of this responsibility falls on landlords. As the property owners, they can ensure proper repairs are made and that servicing conforms to acceptable standards.

Whether landlords opt to share the maintenance responsibilities with their renters or not, keep all the maintenance records in a safe place to ensure faster resolution to problems when they arise.