not hot enough for ya??

[CornBall]

OK, I have hooked up my heat tape and ran it down the back of the rack (used 11 inch heat tape), it gets warm but for some reason it's not getting hot enough. I have both racks hooked up the same way and as all guides have said. The cornsnake rack works fine and gets to the right temperature pretty quick. they are both hooked up to dimmers and are turned to the MAX.
But the BP rack takes a long time to get warmed up and only gets up to 86.2 (I have been running it for almost 24h). I have three different thermometers going (the max/min probe kind) and that's what it has read.
I thought it might be the connectors so I changed them, re did the wiring though it was fine.

any ideas or tips to get it warmer so my balls don't freaze.

thanks

-Ryan