Under Floor Pipe

[Palustris]

At some point in the past (before we bought this property) the back boiler on solid fuel fire place appears to have burst. The metal parts of the fire have all rusted away. So, we removed said fireplace. One thing it did have was an ash bucket set in the floor (at least 15 inches deep too). Again rusted away to not much more than dust. Removed it and discovered a cast iron pipe going from the ash bucket to a vent in the wall on the opposite side of the room.
So that's the back ground. Two questions. 1 What was it for originally?
2. Can I block it off at both ends since it would have no function once we have a new fire of some sort fitted?

TIA.

[Old_Geezer]

1 Dunno, but suspect to supply air for the boiler.
2 Can't think of any reason not to. Or you could dig it out.

[The Builder]

Agree with Og.
Most likely to supply combustion air to the fire.

No reason to keep it......... unless the new fire needs an air supply.

[Zacs-Master]

Make sure whoever fits your new fire is HETAS registered and is fully familiar with part J of the building regs.

[KARL]

The pipe is almost certainly as said, an air inlet. Would you consider having a blank wall with no pretence or nod toward outdated methods of heating ? It saves a lot of faffing about (not to mention probably wasted energy) and renders otherwise dead floor/wall space usable.

[Palustris]

No decision as yet on what we are going to do with the old fire place. It was in fact 13 feet long with a tiny 29 inch fire not even in the middle of it. All gone now, just waiting for the wall to be plastered. That can wait until we decide what to do with it. This is a very cold house and some sort of extra heating would be very nice when it it not quite cold enough for the full Central heating to be on.

[KARL]

If you look into it, you will find that a "fire" is likely to be the least efficient form of "occasional" heating possible (a straight forward electric heater is better), and it ruins part of the space available in the room. Insulate well the area that is open before you close it but above all completely seal the top and bottom of the chimney (which I assume you have). There are myths against sealing it but if there were any truth in them then a hitherto entirely unknown physical phenomenon is at work.