I have a victorian fireplace with a modern gas fire installed. The fire place has a hatch at the top to open/close the chimney, which the fitters have connected to a wire to force it to be fully open constantly. However, it loses a lot of heat through this. I believe it is partly ventilated from underneath. How much should this kind of hatch be open? can I close it completely? Can I close it and have a CO monitor? Surely as long as this is OK there is nothing to worry about?
the fitters have connected to a wire to force it to be fully open constantly.
The only reason I'd do that is if it didn't stay open by itself. Even if it seems to, once it gets hot enough it might close. I would not use that fireplace with the wire removed, until I've verified that the flue is cooperative.