Greetings, Some situations arose this summer with regards to frequent air coil freeze protect lockouts (CXM code 5). To resolve these situations it was suggested to raise COOL CFM to max. tap setting (4). This did solve the lockouts in all situations. I'm not incredibly knowledgeable on air system design practices etc., but this doesn't seem like a root-cause fix to the problem. I'm wondering if this has to do with marginally sized duct work systems, possibly high pressure drop filters compounding the problem. These occurences would primarily be in retrofit situations. Any thoughts on this? Thanks,

Good point, low air flow can cause many problems. Dirty filters and air coils, blocked returns or supplies can also cause this. I think part of any start up or even a service call should include supply and return differential, 15-20 degrees in cooling being the norm.