Having a week's break in a recently renovated holiday cottage in Yorkshire. The heating is controller by some fancy circular dial thing which on googling is apparently a Google Nest. There is no user manual or instructions on how to use this in the accommodation. The temperature on the thermostat rather than being set to a constant 19/20 fluctuates between 9, 13, 22 and 17. Randomly. Just tried to turn it up as we were chilly - locked with a PIN. 
Upstairs, the shower is controlled with a similar digital thing which looks very swish but again, no instruction manual and having a shower involves pressing randomly until it switches on.
So. AIBU to think that if you are charging people to stay in a property, you either install a very simple way of controlling heating/shower etc, OR you leave very comprehensive, idiot-proof instructions? Judging by comments in the visitors' book, others have had the same issues.
Annoying.