Lennox 43K47 Rollout Switch MR Flame L220°F

The Lennox 43K47 Rollout Switch MR Flame is an essential safety device for gas furnaces and oil-fired boilers. It is used as a safety switch that detects the existence of a flame. If the flame is extinguished for any reason, the heat causes the switch to open at a given temperature of about 220°F (L220°F). This effectively stops the flow of gas which if left to free flow could cause fires within houses, or even explosions. In other words, the Lennox 43K47 Rollout Switch MR Flame protects your HVAC system by shutting off the gas supply if there is no safe flame.