3711FL a/c issue

[LDFieglein]

Front unit really struggles to catch up much less keep up with temperatures. Mid day setting on 74* will actually be room temp. up to 85*. Even left for three hours and came back to 85* on thermostat. Bedroom does great- look forward to bedtime. Always seems to blow so do not think freeze up is problem.. How do you check vents? read some of that could be a problem. Holiday World could not find problem suggested getting a de-humdifier.

[1retired06]

Something is not right, I would check ducting first thing. Holiday World suggestion makes zero sense to me.

[dieselguy]

Humnnn bedroom and living area share same ductwork ... they just supplement each other. Some here have found collapsed return ducting and installed pvc to prop it open. I assume you have the whisper quiet A/C system with no dump in the central part of the ceiling right under the A/C units. Make sure you don't have a ceiling vent aimed right at the thermostat or bedroom sensor ... it will make the system think it is way cooler than it really is.

[madeforeachother]

Had the same problem with our 2016 3711fl. Solved the problem with a small floor fan set at bedroom door and blowing into kitchen area. It brought the living room and kitchen area temps down to 74-75 degrees. Make sure the dump damper is open in the bedroom ac and closed in the kitchen ac. Still don't understand why no ac vents were installed in kitchen area. Dealer and Keystone had no answers. We never had any cooling problems with any three previous Montanas but the floor plans were close with bedroom at front. Hope this helps cool you off!

[PackerFan]

If you have the whisper quiet A/C in the living room check the return air ducts. Ours were collapsed to the point they were almost closed off. I slid 1" PVC pipe into the ducts and opened them back up. Made a big difference and now the system can breath right. PM me if you need more info.