Heater sometimes hot sometimes not on 2005 Kia Sedona

The expansion bottle is filling up. NO loss of power, oil level normal

Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
1 answer 3 comments
scan codes in a/c module and post so we can adv
what does this mean?
go to a shop and ask them o scan a/c module for codes
Thank you for your time and help