HI JImmy.
If you do work for any of the utilies then you MAY have to have Public Liability up to £6 million, you MAY also have to have Products Liability and provide a duplicate of your insurance certificate. Dont be wise after the event, put a scenario to your insurance company ie. if I am taken ill away from home how long is my equipment insured for inside the locked van? But that is just your equipment, you might have something on hire? Say you were taking a customers rug home to clean, you might have to have a "goods in transit policy" and if you took it home and it got pinched you might you might require a "goods in trust policy" .
Barry