Brand: Intermatic | Manufacturer Part Number: 156T4042A | Big Frog Supply SKU: 156T4042A Product Overview The Intermatic 156T4042A Fireman Switch is a coordinated-control accessory for compatible pool and spa heater and filter-pump timer installations. It is designed to turn a gas-fired pool or spa heater off before the filter pump stops, allowing residual heat to move through the system and helping reduce thermal stress on heater components. The switch works as part of a properly configured control system and is not a complete timer or heater controller by itself. Key Features Coordinates heater shutdown with filter-pump operation Turns the gas heater off before the pump stops Helps extend heater life in an approved installation Rated up to 10 A at 250 VAC Genuine Intermatic pool and spa control accessory Common Uses Compatible pool filter-pump timer systems Gas pool and spa heater protection Mechanical timer upgrades and service replacements Compatibility Use the 156T4042A only with compatible Intermatic controls and heater circuits that support a fireman-switch connection. Confirm the timer model, heater requirements, wiring arrangement, and contact rating before ordering. Installation Notes Installation involves line-voltage controls and heater safety circuits and should be completed by a qualified pool or electrical professional. Disconnect all power and follow the timer, heater, and fireman-switch instructions. Improper wiring can damage equipment or defeat required safety controls. Frequently Asked Questions What does a fireman switch do? It turns the gas heater off before the circulation pump stops so heat can continue moving through the system briefly. Is this a complete timer? No. It is an accessory for a compatible timer and heater-control installation. Why Buy This Product from Big Frog Supply? The 156T4042A is selected by exact model and electrical rating, not appearance alone. Big Frog Supply identifies its verified function and 10-amp, 250-volt maximum so you can evaluate it against the existing control system.
