Van Insurance like Car Insurance comes in three levels, Third Party Only; Third Party, Fire and Theft and Fully Comprehensive. Each level of cover will cost different amounts, the higher costing insurance covering you for more unfortunate eventualities and the lower one covering less. In the event of an accident, a third party policy will only cover the other person leaving you to pay for all of your van and it's contents. A fully comprehensive policy on the other hand will cover you for everything.
There are many ways of reducing your van insurance premiums, without compromising on cover. Make sure you keep all tools and equipment safely locked away from your van overnight (make sure that wherever you store them is secure and covered by your home or premises insurance). Install or upgrade anti-theft devices such as alarms, immobilisers and GPS tracking to your van to deter thieves. Also, consider accepting a higher voluntary excess on your policy, though make sure that it is one that you could truly afford to pay in the event that you had to make a claim.