The ModCombo valve also reduces the number of locations for gas pressure adjustment. There is only one location to adjust for both the high fire and low fire manifold pressure.
Conversion in the field from one type of gas to another is also easier and more economical. The new ModCombo valve is used for both Natural and Propane gas by the addition of an electrical jumper. There is no longer a need to replace the modulating valve and/or regulator springs.
The operation, control logic, and adjustability of the MA control remains the same in the improved WA control, as do all control board electrical components, signal voltages, and signal wire terminations.
Click the links below to view WA wiring diagrams and Sequence of Operations on the Heatco website: