Weekly pay comes in handy when you are on a low income and it has to be said HVAC do pay the National minimum wage, which quite a few agencies don't, however there are agencies who pay more. HVAC can also give a quick start date, I was working within 48 hours of being offered a job., that included getting my DBS check.
Cons
Once you are onboard, that's it,, you don't hear from anybody and it is very difficult to get hold of anybody if you have any issues. Occasionally there are wages errors so make sure you double check your pay slip.