I performed maintenance on four systems one in the attic three in the basement. I looked at all the low-voltage, check the blower motors, clean the flame sensor and changed out two of the UVA lights one for the main level and one for the upstairs system the other two are fine and working. Homeowner wants to wait until they are no longer working to replace systems are running an operating like they’re supposed to. We will need to change all the filters in the spring time they are good as of right now.