Lighting a home fire - advice welcome

[PMG1]

Any advice, recently moved into a new rental property and behind the grate of the fire the previous occupants have bits of block/brick in there. When going to clear the fire out the Ashes are still smoldering hot as well as the bricks.

I was thinking of removing the blocks to allow the Ashes to cool down a bit quicker but wanted to ask was this a bad idea or are the bricks serving another purpose?

Any help would be appreciated if

A lot of older fireplaces are shaped different than new ones (older ones go further back so are deeper) and it can hard to get grates to fit so sometimes you have to use fire bricks to make the new type grates fit, that's what I have to do anyway

Bricks keep heat but I'd be amazed if someone used this method to keep heat? Make sure they aren't hiding any holes.

[screenexile]

Before any of that please get your chimney cleaned. Brother down the same as yourself and started lighting the fire after a few years of not doing it and nearly wiped the family out.

Can't stress this enough!! We rented a property and thought it was 100% for a fire so lit it on the 2nd night and it was going great guns until I went to our bedroom above and it was full of smoke!!!

Got the chimney cleaner in only for him to tell us the chimney was closed!!