Can an older Wall heater be retrofitted with a thermostat connected to the wall ?
( A wall heater about 30 years old 30 ).
Or Does a Home buyer have to buy a new heater for that feature.
David
I would not recommend it.
Nothing lasts forever.
The short answer to your question is no you do not have to replace the furnace but you would have to change out the gas valve to one that operates remotely from a stat.
On a 30 year old furnace I would be concerned about the integrity of the heat exchanger and If converted would probably not be cost effective