you do not have to issue a new LGSC when you fit the boiler, what it means is that when the "existing" cert runs out the landlord has 2 choices, include the 3 month old boiler in the new cert to bring all appliances into line (my preference) if they dont want to include the boiler in the check they dont have to as the boiler does not need to be checked until it is 1 yr old, however this is where it becomes more difficult to manage as the boiler will need to be checked in 9 months, but it is down to the landlord to decide, in a previous job i looked after 14,000 social housing properties and when we fitted a new boiler we charged and carried out a full new LGSC to keep everything in line, however this was because i had good landlords who cared about the tenants and knew it was the best solution, if it wasnt included in the original quote tell him to do one, the only paperwork required for a new install is benchmark(if manufacturer is part of scheme) and warranty paperwork, i did always get our guys to fill out the old CORGI CP4 so that we had some paperwork for the install if we werent doing a full new LGSC but that was my choice to cover us a bit
