Dual Pilot Taps: Factory-drilled 1/4" NPT dual tappings allow for streamlined installation of diagnostic tools and pilot burners

it provides critical boiler overpressure protection for legacy and modern steam systems

making it a reliable choice for commercial and heavy-duty residential furnaces

while the 525 psig maximum overpressure rating prevents bellows failure during system spikes

Maxitrol TD121B Temperature Selector R-410A Dual Pilot Taps: Factory-drilled 1/4"The Maxitrol TD121B Temperature Selector is a critical component for Selectra Series 21 and 31 electronic gas flame modulation systems. Specifically engineered for indirect fired make up air units, this remote selector provides precise setpoint control within a 120 170F temperature range. For a stable discharge air temperature, it must be paired with a TS121B sensor to ensure the resistance curves match the A1010 or A1011 amplifier logic. This