Welcome to the 13 th Annual TSA Conference, 2016

Dave Koesterer Dir. of Engineering Performance Systems Furnace Updates

MPL Series 9371MPL 9375 Series M1 Series Pressure Switch

Field Issue – “Chattering” Gas Valve Field Issue – “Chattering” Gas Valve Requested switches and furnaces returned under SR program Requested switches and furnaces returned under SR program Investigated Root Cause Investigated Root Cause – Issue confirmed Field Issue sequence of events Field Issue sequence of events – Successful ignition – Momentary loss of vacuum – Pressure switch opening – Voltage drops to gas valve – Gas valve begins to close – Vacuum regained – pressure switch closes M1 Series Pressure Switch

Sequence cont’d… Sequence cont’d… – Cycle repeats up 1 to 4 times The Issue… The Issue… – New switch series has less internal volume – Quicker response time The Solution… The Solution… – Dampen or slow down the switch response time M1 Series Pressure Switch

Action Taken Action Taken – Developed smaller bleed orifice – Requires new tooling for orifice Application Testing Application Testing – All M1 models – Normal and reduced voltage – Input: Normal, reduced and over-fire – Fuel: Natural gas and LP – Cold and Hot start-up M1 Series Pressure Switch

New Switch Target Implementation New Switch Target Implementation – Early October, 2016 New Switch Part Number New Switch Part Number – R New Kit Part Number New Kit Part Number – R – Includes switch and tubing M1 Series Pressure Switch

M7 Series Igniter M7RL and M7TL Series M7RL and M7TL Series – Single and Two-Stage Requested failed igniters from the field Requested failed igniters from the field Component Failure Analysis Component Failure Analysis – Micro-Fractures in Ceramic coating – Delamination (blistering) Potential Root Causes Potential Root Causes – Mechanical stress in handling – Mechanical stress in transit – Thermal stress – Defects in manufacturing

M7 Series Igniter Reliability Testing Reliability Testing – Developed accelerated life test – Forced failures to predict igniter life – Confirmed Voltage vs Temperature Curves – Target 100,000 cycle life Ignition Test Conditions Ignition Test Conditions – Voltage: 81V, 115V, and 127V – Cold and Hot start – Natural gas and LP – Pressure: Reduced, Normal, Increased and min. rate

M7 Series Igniter New Supplier Selected New Supplier Selected – Silicon Nitride – CSA Approved Design New Igniter Part Number New Igniter Part Number – TBD – Backward compatible Target Launch November, 2016 Target Launch November, 2016

90+ Front Collector Box Seal Models Affected: G7 and M7 Series Models Affected: G7 and M7 Series Field Issue: Condensate leaking from front collector box Field Issue: Condensate leaking from front collector box Requested Furnaces from the field under SR program Requested Furnaces from the field under SR program Sampled warehouse inventory Sampled warehouse inventory Root Cause Investigation Root Cause Investigation – Improper application of “grey” sealant tape

90 + Front Collector Box Seal Solution Solution – Pre-cut tape length for each cabinet size – Update work instructions – Emphasize ½” joint overlap – Conduct new process training session for employees

90 + Front Collector Box Seal Date Range affected Date Range affected – Starting July 1, 2015 Solution Implemented November 4, 2015 Solution Implemented November 4, 2015

G7 1 HP PSC Motor Set screw on 1 HP PSC motor assemblies loosening Set screw on 1 HP PSC motor assemblies loosening – Motor PN – Caused by fretting induced by motor/wheel vibration – Motors repositioned in motor mount – Effective date 3/20/15

G7 1 HP PSC Motor New Motor created to further reduce torque pulsations New Motor created to further reduce torque pulsations – Part number R – Implemented on 8/23/16 for all G7 applications New Replacement Blower/Motor Assembly New Replacement Blower/Motor Assembly – Part number

Customer issue: Secondary twinned furnace cycling on and off Customer issue: Secondary twinned furnace cycling on and off – No faults recorded on the ignition controls Jobsite visit to observe (4) pairs of twinned furnaces Jobsite visit to observe (4) pairs of twinned furnaces Set Up Set Up – All wiring according to kit instructions – Primary Furnace connected to thermostat with >100’ wire Findings Findings – On a call for HEAT, Twinning Boards communicating – Primary furnace normal operation – Secondary furnace cycling – No faults observed on secondary furnace G7 PSC Twinning Kit

Findings cont’d… Findings cont’d… – Ignition control exhibiting loss of pressure switch signal behavior Controls Engineer monitored ignition board function Controls Engineer monitored ignition board function – DC waveform to ignition board microprocessor monitored – When gas valve was energized, DC power dropped and a “false” open pressure switch signal caused the gas valve to close 75 VA transformer tried with marginal success 75 VA transformer tried with marginal success – Voltage drop still present Solution: Control Secondary furnace with separate relay Solution: Control Secondary furnace with separate relay – Control power for secondary furnace is from its 40VA transformer G7 PSC Twinning Kit

Wiring Diagram with new Isolation Relay Wiring Diagram with new Isolation Relay G7 Twinning Kit

Technical Bulletin to be issued Technical Bulletin to be issued “OLD” Kit “OLD” Kit “New” Kit “New” Kit G7 PSC Twinning Kit

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