HVAC yearly maintenance and cost

[Samantha Klein]

This question is for the landlords here,

I have 6 properties, some with wall furnaces instead of traditional HVAC units in the basement or attic. How often do you have these checked on and cleaned? What is the cost per unit?

I just visited a local HVAC company that has a yearly maintaince program and they said it was $98.25 per unit. This is per furnace unit. One of my properties has 4 wall furnaces. They wanted $98.25 EACH unit. That seems high to me. What is everyone paying?