If it's a room sealed boiler ie a combination it should be ok where it is.
Just box it in and put some cooling vents in. Allow access for servicing.
Consult manufacturers instructions which can be down loaded.
Also fit a CO detector local.
always allow for 1 in a 1000000.

Just re re read your query ,
It would all depend on age and condition of current appliance
I wouldn’t leave it in the bedroom unless you have a hard wired CO alarm
If it is relocated make sure all flue and casing seals are checked and replaced if nesscesary
Finally ,please have a Gas Safe engineer to have a look ,most of us do free quotes , little hint the lower the Gas Safe number the more experienced the engineer is , Good Luck