It's all the same as domestic just bigger. But I would suggest that if you have no experience on commercial then I would suggest pairing up with someone who has
Have you ever worked on com. Have you got any work for commercial.
It's a bigger type of fish than domestic with the regs. And if you haven't got alot of experience on domestic I would say to really build on that knowledge so that your in better stead for the com world
For example. You cannot just replace a gas valve on a commercial boiler. It requires a rather expensive analyser and about 3 hours depending on load of commissioning
I have been domestic for the past 11 years and I am good at installing but I have mainly carried out service and breakdowns where I can get my head around most things and am good at fault finding.
I have domestic gas/ LPG and also Oil.
I would like to be able to work with somebody but there is nobody on the company that I work for who can touch it.
I know its going to be a very steep learning curve (as it was when I did my oil but after a few jobs I was ok 18 months on im as reliable as with gas) I am prepared for that and expecting it to be harder than picking up oil but going to be worth it.