Humbaur refrigerated trailer

[dangcornish]

Hi all, my mate has just bought one of these trailers but the lower setpoint is 4 degrees, he wants it at 2 for meat. its a monoblock type with 7 buttons under the display. no identifying marks at all unsure how to access the parameters menu any help would be great if u work on these type of things.
Before you state the obvious yes i could just change the controller!!!

[cadwaladr]

what make is the monobloc? have you taken the covers off it to find some more details

[dangcornish]

only had a quick look in the dark! apparently humbaur spec the same unit for all their trailers, hoping someone had a little knowledge of these trailers