I had the same unit with the same problem ("LLLL") - I emailed them a picture of the display, and then decided to call the customer service number (I was too impatient to wait for the response over a long holiday weekend). They put a new one in the mail the same day. Great service!
I ended up upgrading to the Thermapen shortly thereafter . . . ;)
Rec Tec with bull horns -- UDS (Big Blue) -- 2 Weber kettles -- Weber gasser -- DCS outdoor stainless built-in nat. gasser with smoker box and rotisserie -- Dutch ovens a-plenty -- bright yellow can't-lose-me Thermapen