Just want to post a good report of my experience with Kelly controllers.
It was cheaper to buy a new Kelly controller than have my old Curtis controller repaired.
I was advised to go for a higher rated Kelly to replace the Curtis, so I did, (as the ratings are for peak amps), but I am really pleased with it. Free software and cable, good price, free postage, and it works well. It was simpler to set-up.
The nightmare I was having with Curtis repair and config is over. Fany from Kelly was helpful by email, and the controller is better in every way!