Hot water and heating control with my Mitsubishi Ecodan Air-Source Heat Pump (ASHP)?

Hi all, well this guy wasn't great....he zoomed through the whole walk through and controls, he basically changed some and didnt show me how...I think he went into service and entered pass code, as cannot get into the water temps.  But he reduced my water temp which was stupidly set at 60!!!  So no wonder it was too hot, its now at 50.  He also changed the legionnaires which was set to come on at midday, now 1pm!  Length to heat was 120, now 1hr, it's every seven days I noticed, and he upped the running time from 5-10 mins! I questioned it he said needs time to kick anything off...I said do I actually need this setting he said yes so.  He reckons I should see how I get on with it on constant now as it best way...but I can ring them anytime to change it to timer.   So it was ok in some ways but not so much in others.  When it gets serviced I'm going to ask that person go through it properly and let me record his fingers as he does it lol.  The hot water didnt come on this evening, thank god,its at 41 now so it will come on in the night and fingers crossed it always does....if not I'm going to ignore his words and put it on a timer! 

Thanks again everyone.   If anyone knows how to get into the service part let me know? Thanks 😊 

Well the water being a lower temperature is great, not burning my hands and it isn't turning on at peak hrs.  It's not cooling as fast....so now to see the cost.…

Oh yes something else the guy said, was to only have one big appliance going in summer at a time, as in my air con only, not washer too....as the solar won't cope....how does he figure that?  Is this right?  Seems weird 😕 

@Auds i understand the risk of legionella is when there are airborne droplets you breathe in, you can safely drink water contaminated with legionella - so showers are highest risk activities with all the water vapour created.

Given that you are only filling sinks a cycle every 2 weeks should be appropriate - I think this is fairly common practise even in installations with showers from the cylinder. 

Heat geek and HSE will be reputable sources to make your own assessment.