Provides safe gas ignition control and flame monitoring for 120 VAC gas burner systems
This guide explains how to safely convert applications from the older Fenwal 05-14 analog controls to the newer 35-70 microprocessor-based ignition control. It covers terminal designations, wiring differences, grounding schemes, and agency approvals. The 35-70 offers improved flame sensitivity, LED diagnostics, polarity-insensitive wiring, and multiple lockout recovery methods. Key changes include the use of a B.GND terminal for burner grounding and the elimination of a manual reset button.
The guide also includes a cross-reference chart for popular control models and notes on specific wiring configurations, such as Single Spark and Sense versus Local Sense electrodes, and terminal orientation differences on the high voltage transformer.
| Ignition Control Type | 120 VAC Direct Spark Ignition (DSI) |
|---|---|
| Accuracy | Ignition and purge timings +/- 5% |
| Agency Approvals | UL 372, UL 1998, CSA: ANSI Z21.2, FM (pending) |
Single Spark and Sense uses the high voltage wire to both supply spark energy and pass the flame sense current, eliminating the need for an additional sense wire. Local Sense requires a separate sense wire.
The 35-70 replaces the 05-14, 05-13, and 05-38 controls.
The 35-70 is a 120 VAC control.
The B.GND terminal is used to ground the burner and complete the flame current signal circuit.