If you look at any EA brochure most, all probably, of them carry this sort of disclaimer at the bottom.
They have to do it, so that Mr. X doesn't come crying to
them the day after he moved in and his washer won't spin - like they are going to give a monkeys about that, they did their job. That's the only reason they put it on. In a way it kind of draws it to your attention doesn't it? By the way that washer might look shiny but it might not even turn on

Obviously biggies like central heating etc. definitely needs to be seen working. We had two faults on ours the month after we bought at £160. It worked when we got it though so you can't be sure!
They say in viewing property advice things to turn the taps on and off, check the lights in the room and flush the toilet. All these things, I'd say are second viewing fodder.
Have you only been the once? If so, if appliances play that big a part in your offer, why not go and casually ask to see them working briefly?
I'm not sure they'll let you do a full coloured wash, but they might let you turn it on and off again to see it working!
All in all, I can't say it would ever really worry me - not weighing up say a washer against a house I love.
Good luck and oh, try and wait till Monday, as it looks less eager!
An excited FTB, I myself rang up on a Saturday straight after I got home from the first viewing
not exactly playing it cool!