i would move it after you confirm the precise new location based on furniture arrangement but can you post a plan showing dimensions of all living areas with window and door locations?...this wall may be the best location for the TV but is it also the best location for the heater?? although plumbers fees may only be for a few hours work i'm wondering if a reverse cycle AC may suit this room better and relocate the gas heater to another room but it's usually a better ideas to live in the house for a while before making big changes??

I would also like to see more room details, dimensions, marking doors windows etc, looks like the heater was an after thought by the previous owners, the aerial point is smack bang behind the chimney

I'd leave it or take the opportunity to remove it entirely.

I took your advice @oklouise and have lived in the house for two months and am no closer to a solution. The fireplace definitely doesn’t work on the wall and sliding the fireplace 1 metre to the right isn’t the best idea either. It also isn’t the best heater and I’m leaning towards getting rid of it. But the room is definitely cold and I can see why they added it in as an afterthought. I’m posting a floor plan in hopes that someone sees the ideal spot for a gas fireplace in this room.

what a pity but, before you consider another gas fireplace arrange a quote for reverse cycle electric air conditioning that is cheaper to run and install although more expensive to buy the units, add a door in the hallway near the wiw to block the heat going upstairs but, if you prefer the gas heaters, ask a gas plumber if it would be possible to have a new gas heater located on the pantry wall with a power flue and gas supply pipe built inside the pantry and laundry and the external flue located outside the laundry away from the kitchen window but also check insulation in the ceiling and try insulated curtain liners but how do you heat the living area?

There's a move away from gas, new suburbs here in my city aren't even getting gas pipes laid in the streets. Go reverse cycle, as the name says it will benefit you in summer too.

As much as I love a good fire. I agree with above to have a look at a split system. I don’t think those faux fire gas fires are known for being effective and efficient. It certainly takes up a lot of space. I love my wood fire but the split system is practical all year round. I also love my gas central heating but the split is cheaper to run.

It appears in your photos that the place is not too old. But be aware depending on the age of your fireplace it may no longer be up to the latest Australian standard and therefore any good tradesman will not be able to reuse it. I have just gone through this dilemma in my upcoming renovation.