Related illustrations

0831

Primary controller

· p. 139

The illustration shows an older oil-furnace primary controller, also called a primary relay or stack relay, mounted on the exhaust vent connector at a chimney. A heat probe extends into the connector, and an arrow indica

1586

Primary controller

· p. 277

The illustration shows an older oil-fired water heater vent connector entering a chimney, with a primary controller mounted beside the connector. A heat probe projects into the exhaust path to detect heat as evidence of

1588

Primary controller

· p. 277

The illustration shows an older oil-fired water heater primary controller mounted on the exhaust vent connector entering a chimney. A heat probe extends into the connector to detect heat from the water heater exhaust, an