Your obligation as a landlord is to pay some numpty gas fitter 40 rips to test your house is gas safe,if he gives you that doc, cushty,if he highlights anything,he should explain in writing if you are not present any further action required by you. End of. Bing Bang Billy Bish Bosh.!
By eck, £40 for a Landlord Gas Safety Certificate is cheap. Whoever you've got must be a numpty gas engineer, either that or your properties only have a gas hob on the gas installation. But there's not much change when landlords charge around £600 pcm.
James