new sump= Major problems

[fkshiu]

Get several thermometers and make sure they all agree.

Place them throughout your system.

Unplug each electrical device starting with your heater(s) one by one each hour or so and closely monitor the thermometers. Unplug your return pump last.

OR it could be that with the added humidity in the general vicinity the evap rate is being limited thereby leading to an increase in temp. Solution? Open some windows.