LOL reading this thread! Some people are unbelieveable. I have only been at it 6 months and haven't come across anyone as bad as you guys have yet. Most customers I have experienced have been fine, I get a few tips which always puts a smile on my face, I'm still fairly slow at what I do but i'm always super polite and helpful. One old guy even gave £10 on Wednesday then came and put my ladders on the van for me haha, I couldn't get him not to!.
Customers standing and watching me work does my head in as I am still inexperienced so I don't want them to see me do something wrong or watch me trying to figure out what bend would be best lol. (if they leave me to get on with it I know any mistakes can be put right and I won't be flapping).
When putting in a new boiler and the customers constantly moaning they are cold can be annoying though. What do they expect with no central heating? Go and put a jumper on!
Working for a company means if there is any bad customers I might get an ear bashing but the manager can deal with things and I can just be yes sir no sir. Being self employed and customers refusing to pay must be tough going, I'm sure you all get angry if it happens but there's not much you can do as you can't risk your reputations, I know that I would want to put a brick through each of their windows or throw paint all over their car haha.