SOUTH BEND, Ind.---With temperatures expecting to drop in the mid 30s this weekend, HVAC professionals are reminding people to have their furnaces and heating systems checked before turning them on. They are experiencing a higher number of calls this weekend do the changes in temperature. 

Some of the common problems contractors see are: 

• Frozen pipes
• Uneven air flow
• Malfunctioning heating pumps
• Dirty filters
• Broken thermostats 
• Faulty pilot lights 

and 

• Carbon monoxide leaks.

In addition to having your furnace serviced, HVAC contractors also say they are measures you can take to keep your furnace working properly. They include:

• Checking/replacing air filters 
• Checking batteries on thermostats

and 

• Make sure smoke and carbon monoxide detectors are functioning properly