where in a gravity fed central heating system can i find the check valve?

Answer 1

You may not have one to find?!! What's the problem?

Answer 2

Gravity heaters are so called becasue they rely on the heating of air to move the air - there are no blowers. Typically they are used in small 2 bed 1 bath houses and are installed under the house with some kind of floor vent usually between the bedrooms. There are no valves on the heated air in this system. The only valves will be on the gas line to the heater furnace itself.

Answer 3

Suzanne you probably won't have one
Nginr what are you talking about ? I'd go and have a lay down if I were you !