hi there, i am a landlord and although i don't deal with gas, my husband is a plumber, and services gas/ oil boilers regularly, all gas , electic oil boilers should be serviced annually, and gas must be checked by someone who is corgi registered, i hope this helps,xx really not sure about figures, if you are really concerned you should maybe get the gas checked out yourself and send your landlord the bill, she should have to pay it, also check out the small ptint of your lease, just in case it says that you may be responsible for it yourself. the cab have a great book for landlords and tennets, if you can get hold of that it gives you a lot info.xx