A Gas Safety Inspection is not included in HIPS, so it is your responsibility to find out when the gas appliances where last inspected. Ask the vendor for a copy of the Gas Safety Certificate. This should show the CORGI registered installer if before 01st Aprill 2009 or the Gas Safe Registered installer if after that date. If they cannot provide this get a Gas Safe Registered Engineer to complete the inspection on all gas appliances (Boiler, Gas Fire and Gas hob/oven).
It is the Landlords responsibility to provide the tenant with a Gas Safety Certificate. To be valid this must have been completed within the last twelve month. Gas Safety Certificate are only valid for twelve months from the date of issue.