That's the thing. A Service is, a strip down service, should be carried out every year. Any other type of service work, is called a Service Maintenance check and Not a FULL SERVICE.
Raj mate, you need to show ‘Safe Isolation’ for the electrics first. Remember there’s DaftyDIYers follow these videos too. Also, you never shut off the Gas before disconnecting the Gas Valve. But hey, apart from that, it was very informative.👍