I would start with a small bit of water and see what it does. You certainly want the bowl full, just to keep sewer gas out. Simply flushing it may work but if it doesn't you will have a mess.
Add water to what seems to be the normal fill level in the bowl and slowly add more to see if it goes down OK. After a few gallons If all looks OK try a flush
Be careful if the bowl is dry and there is no sewer gas smell. (plugged pipe)
There might be a good reason the past owners quit using it
Test it out by pouring lots of water in the bowl first
Once you flush it, it may just keep going, if the flapper is dried or the fill valve sticks ,and even the shut off may need a bar to move.
AMUN
I recently bought a hoouse, and the basement bathroom apparently has not been used in years. The toilet bowl has no water in it, and it is completely dry. Can I simply give it a flush to fill the bowl back up again, or do I need to dump a coule of buckets of water in there from another source?
Thanks.
Assuming everything is working as it should, that is all you should need to do. However I suspect it will not be that easy. Years of non use is not good for most mechanical things. I also wonder why you are not complaining of a strong sewer gas smell. I would also worry a bout the possibility this toilet needs a pump and that may not be working.
As long as you know where to turn the water off it it, you can try one flush and see what happens.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.