Dometic Freshjet zircon

My remote for the domestic aircon on my 2013 Lancashire has chosen to work on an adhoc basis. I have sourced a universal remote and have spent the last hour trying to link the two. Although I can get a reaction from the unit on several numbers I cannot get all the functions to work. Does anyone know the three figure code needed to achieve this? Thanks

Not an answer to your question but how are your DIY skills?

I’m assuming you have eliminated flat batteries. I’ve had many remotes play up over the years and have had a pretty much 100% success rate by taking them apart and giving them a good clean.
Plenty of YouTube videos showing the best way to do it.

Yep even splashed ot on Duracells!

There are I guess 999 possibilities . I have already find four that will get the unit to respond but the thought of the other 800 leaves me looking for a quicker solution.