Overview Reviews Product Description Module, Timer, Purge, 10 Second, Honeywell Part Number ST7800A1021Honeywell Process Solutions products are only available in some markets. Please call for more information. Product Videos Custom Field Product Reviews (No reviews yet) Write a Review Write a Review × Honeywell Honeywell ST7800A1021/U Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name *Email *Review Subject *Comments