I have an existing stat that has two wires coming out of the back. A blue one and a black one. The black is hooked to a black one in the box and the blue is hooked to a red in the box. On my new LUX LV2 stat there is a red line wire on the back and a black load wire on the back. What do I connect the wires to? I have no tester. I had red to red and black to black earlier and nothing came on heat wise. I am thinking switch them but thought I would check here first.. Any help would be greatly appriciated!

First, get a tester. Find out which is the line and which is the load. The rest is self explanatory.
OK, that is what you should have done. Why you would even attempt an electrical project, even a simple one such as this, without even a tester makes me wonder.

At this point the only other option is to try the other combination.
Only thing is, while those t-stats are polarized, meaning there is a line and load, it should work even if hooked up wrong. Maybe not with this one.
Try it and see.

Here is your factory wiring diagram

http://www.luxproducts.com/ART/suppo...V2-LV3_ENG.pdf

Here is your trouble shooting diagram

TEMP REGULATION
Model LV2
Description
Heats more than 5 degrees
Past its displayed set temperature Verify that your thermostats electrical connections are clean and tight.
Verify that your units placement and mounting are optimum per the installation section of it's manual.
Replace unit. There are no user serviceable parts

.
No heat when expected. Refer to wiring to verify that it is according to the unit's wiring diagram. Verify that all connections are to your thermostat are clean and tight.
If room temperature is greater than 90F the unit will not close it's switch and call for heat.
Rotate the dial to its highest setting. Heat should operate immediately.


Heat Test Slowly rotate the dial toward its lowest setting. Listen carefully for a small click near room temperature. When it is heard, the unit should switch off heat immediately.


Advanced Trouble Shooting This thermostat is designed to switch hazardous voltage. Qualified service personnel may use the following information to trouble shoot the system.
The LV2 uses a separate switch for each side of the AC line. One is a normally open single pole snap-action switch. This switch controls heating when the dial is above its minimum position. It should open when hotter than its set temperature and close when cooler than its set temperature. Both switches are forced open when the dial is rotated to its off position.