Symbio 800 IntelliPak going into a Loc 3 or Supply Air Proving Lockout

Issue:

IntelliPak 1 with Ultra Modulating Option and IntelliPak 2 with Modulating and Staged Heat options w/ software revision previous to 4.10.002. 

IntelliPak 1 and 2 units with the Midco VA burner after a power cycle and an initial call for heat (Manual or Auto Mode) go into a LOC 3 diagnostic on the Siemens controller or Heat Supply Air Flow Proving Lockout at the TD7 display.  This Service Alert only pertains to units where the combustion fan does NOT come on after an initial power cycle and a call for heat. 

Problem:

After an initial power cycle, the 3KF40 MOD Heat Signal LLID initiates 0 vdc at the 2-10 VDC OUT signal.  This is NOT correct and the minimum voltage at this input is 2 VDC.  For the Combustion fan motor to start, the SCBEM motor controller must see a 2-10 VDC signal.  Since the output signal for the 3KF40 MOD SIGNAL module is only outputting 0 VDC, the combustion fan does not come on.   This results in a LOC 3 or Air Flow Proving Lockout. 

Solution:

DO NOT POWER CYCLE UNIT!

Clear the diagnostic/alarm on unit’s TD7 display.  The MOD Heat LLID output signal will now read 2 VDC.  This is a software glitch that will be fixed on the next software release with an estimated release date of 10-2024. 

This problem will always be present after any unit power cycle until a software release is issued.  If the unit must be powered down for maintenance or troubleshooting, you will need to run a heat cycle in Manual Override after the completion of work to correct issue. 

 Symbio 800 Manual Override

10/2024

This issue has been resolved with Symbio firmware upgrade of version 4.10.0002 or later.  

IntelliPak Symbio 800 - Replacing controller and updating Firmware

WARNING:

Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.