Can anyone give me any information on when a fail safe circuit using a thermocouple or pilot generator for a heater became standard for household use or when it became mandatory for manufacturers of furnaces.
I have an Adrews floor heater. Yes it?s VERY old. It doesn?t seem to have a fail safe circuit. I am very curious as the whether it never had it or if someone messed with it.
Yes I know all about pushing in and holding down the pilot control rod to light the pilot but this rod isn?t going down or up, it only turns. Yes I know I should replace the entire heater and I am in the process of replacing it now or very soon. I am simply curious about its operation that is all. Any historic information you can give would be greatly appreciated. Thank you.
Molly,
Since you have the red button you need to push to light the pilot, you do have a gas safety valve. The red button allows gas to flow to the pilot light until the pilot light heats up a thermocouple. The thermocouple creates a small amount of electricity when heated and that holds the safety valve open allowing gas to flow to the main burner. If the pilot light were to be extinguished, the power flowing to the coil in the safety valve would shut off all the gas.
If you have concerns about the safety of the furnace, you gas company will usually perform a free safety check. The biggest concern with something that old is a cracked heat exchanger. If the heat exchanger is cracked the flue gasses could enter your home instead of going up the flue pipe.
The old unit is also a lot less efficient than a modern furnace, so you are burning more gas than you would to get the same heat with a more efficient unit.
Hope this helps.