I had a room added on to my house over the summer and a PurePro D110 thermostat was installed, but no directions were left with it. I have tried to find a manual online, but have had no luck.
It works OK, but I don't think I am getting the most efficient use from it because I am not sure exactly what the unmarked slide switch controls. Anyone familiar with this product?

I hope this helps. I believe the company that makes this product is called RegO. Maybe contacting the company directly will help you obtain a manual. The address for them is:
PurePro®
1 Bon Terrain Drive
Amherst, NH 03031

Additional info:

New Hampshire
F.W. Webb Company
1 Bon Terrain Dr,
Amherst, NH 03031
Tel: (603) 882-1945
Fax: (603) 883-4256
Email: [email protected]
F.W. Webb Company