most people wont move existing boilers due to too many risks eg not working afterwards etc
It they were from the major boiler mfrs then they are specifically in the business of fitting new boilers and won't want to move old boilers.
(And if the boiler has "done it's duty" and your not on the bread line why not get new - energy efficiency etc etc)
Its more a case of - what happens if the boiler does not work properly when moved. Whose risk is it ?
He said a new boiler in a new location not move his existing boiler to a new location.