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Control Board Timer Replacement for Coleman Blend Air System. S1-7681-318P

Sale price $ 344.50 Regular price $ 413.40

This timer kit is designed to replace both the upper and lower control boards found in your Coleman Blend Air System.  

The Coleman Blend Air System found on many mobile homes is now an obsolete ventilation system. Most parts are still available, but in time those parts too will be obsolete.  Many of the available parts have skyrocketed in cost.  

The purpose of the Blend Air System is to vent the attic and bring fresh air to the furnace. Ventilation is done by the blower on the roof running 4 hours on and 4 hours off 24/7. This is accomplished by an expensive overly-complicated system of 2 control circuit boards (upper and lower) communicating with each other.  The lower control board, typically found in a box on the outside of the furnace, also opens a fresh air damper while the furnace is running, and beeps when the motor on the roof is no longer running or there is a communicating error with the upper board.

With this kit the upper and lower boards are replaced with a timer installed in the control box of the blower assembly on the roof. The timer will run the blower 4 hours on and 4 hours off 24/7.  The flapper of the damper is also removed.  

IMPORTANT: With this updated system, there is no alarm to notify the homeowner that there is a problem with the motor on the roof. If you can’t hear the motor running, then you will need to do a periodic (monthly) inspection.   You will also no longer have a damper that opens and closes for fresh air. The damper will remain open. This is how fresh air systems of other brands work.   IF YOU CANNOT ACCEPT THESE CHANGES, THEN DO NOT USE THIS KIT. Instead, repair your system by purchasing the original parts, if still available.


  1. Install the timer on the roof by removing the control board and harness. The two wires from power connect to the 1 & 2 terminals. The two wires from the motor connect to terminals 3 and 5.
  1. Locate the damper assembly at the top of the furnace. Access the damper by removing the filter. Remove the motor and flapper from inside the damper.
  1. Remove the lower control board. Be sure the thermostat is hooked back directly to the furnace. In most cases you will have to do nothing.

Detailed instruction are included with the order.

This kit will replace all of the old Coleman Blend Air Control Boards and timers including the following part numbers: 7681-3091/A, 7681-3091, 7681-309, 7681-317, 7681-317P, 7681-317P/A, 7681-318, 7681-318P, 7681-308, 7681-3081, 7681-3981 & 7681-8291/B.

NOTE: This kit must be installed by a qualified HVAC technician.   By installing this kit, the installer agrees to hold the seller/manufacturer not liable for any and all damage or harm caused by the installation or mis-installation of this kit.   Also before installation, the blower motor on the roof should be inspected to insure it is in good working order.