Explanation of factory option MERV 8 Koch filter vs. previous AAF MERV 7 air filter.

Update on Current Salesforce Case Access and Open Globe Migration

S1-THXU280 (B, W) Thermostat Software Update for Variable Capacity Air Conditioner of Heat Pump

Ignition Control Board Defect; Residential Single Stage PSC Gas Furnaces

LX Series Residential Package Unit Defrost Curve Selection

RRS Economizer (2EE04709324) Commercial Accessory (Field Installed Only) - Infinite Boot Loop Issue

Enabling Low Ambient Kits on Simplicity Smart Equipment (SSE) UCB.

SSE Alarm "Economizer Communication Error"

This letter provides the new burner box wrapper part numbers for the non-condensing gas furnaces.

SSE Control - Discussion on Operational and Operating Values

Coil Cleaning

ST-005-17 SSE Startup

YS-008-17 CondensateMgmtIssueNewPlatformNcoilsandAirHandlersRev1

VAST-17-002 YHE Sensor Failures

YS-004-2017 Non-Condensing; 80k BTU; Burner Ignition Issue

YS-006-2017AlternateR22Refrigerant

ST-006-16 EB Blower Noise

Communicating thermostat firmware – New platform communicating air handling units

ST-007-16 MH Equipment Application Update

St-008-16 TTSCC02 Security Update

ST-010-16 LP Conversion Kit S1-1NP0347

ST-012-16 S1-THXU280 HEX THERMOSTAT UPDATE FOR COMM

VADST - 006 - Flood Damaged Equipment

VAST-16-06 80% furnace ignition issue

YS-001-16York Flood Damaged Equipment

YS-009-16YorkNoFaultFoundControlBoards

YS-014-16andM-429-2016 letter EPA warning R-22a 0501016

YS-016-16 CM64D Horizontal Condensate Management

YS-017-16 LX ResPac Burner Ignition Issue

ST-004-16 Mercury Res Pack Unit Data Plates

ST-011-16ResSplitSystemDefrostCycle

YS-015-16 York  LXSeries Package Cabinet Sweating

VAST-16-002 6HK electric heaters with circuit breakers on AP-AE air handlers.pdf

ST-003-16 Communicating Thermostst Wire Harness

ST-001-16 LX Series Pkg HP and Split HP Defrost Boards

ST-002-16 Auto Update UCB

YS-001-15RegalBeloit751hpBlowerMotorsYORK

YS-SP01-16 Defrost Sensor Placement Gen 7

YS-022-15 York Electic Heat

Blower Initiation Failure in NON-Heat Pump Electric Heat Applications in Packaged           
     Unitary Commercial Models, EXCLUDING 15-25 ton, and 108kw Millennium.

VAST - 006 - Flood Damaged Equipment

ST-030-15 York Platform Matchups Legacy Air Handlers & Coils

YS-033-15 Refrigerant System TEV Performance Issues

ST-020-15 York 33 inch Modulating Gas Furnace Stuck Gas Valve Issue

YS-010-15 Inducer Motors Single Stage and Modulating Gas Furnaces

YS-SP007-15 Suspect Limit Switch

ST-007-15 York High Limit Trip

Residential Package Unit - Defrost Control Operation and Diagnosis

ST-011-14 York 33 inch Furnace Combustion Air Intake Drain

ST-004-15 ResPac Control Wiring

2014 CCE Contractor Program requirements for the 100% money back guarantee or first year unit replacement to consumers

33" 80% Gas Furnace – Silicon Nitride Ignition Issue

YPLC, TM8V, TMLV, TM8T, TMLT, TM8X, TMLX, TG8S & TGLS Units

Diamond 90 – Single & Two Stage Gas Furnace Primary H/X Availability

TM8V, TMLV, & TM9V Dehumidification Cooling Airflow Operation

Touch Screen Communicating Control S1-TTSCCxx Warranty Claims

ST-021-14 UTEC ICB Ground Wire

VAST-14-006 TXV's Sticking or failing in Commercial or Residential Systems

ST-033-14 RefrigerantSystemTEVperformanceissues

ResPack Fan Blade Clearance and Furnace, Air Handler and ResPack Blower Motor Mounting Dimensions

 Residential AC & HP system contaminants affecting TEV performance

Retrofit Application of Commercial R-22 Split Systems with R-410A Products

2.0 & 2.5 Ton – 16 SEER; Z-Chassis; HP Reversing Valve YZF Units

Obtaining the Cost of a Major Component in lieu of a Unit Change Out

Simplicity Control Package Heat pumps with nuisance fault code 9

ST-009-13 York Guardian Dry charge POE

Affinity Gas Pack two stage with single stage thermostat

The attached service letter details the cause and effect of a resonance issue in the discharge line that could cause a stress fracture in the copper. 

In an effort to address occasional requests for missing condensate accessory bags in the upflow and counterflow 90% residential furnaces, a Bag O’ Parts will be offered through Source One Parts.

Due to several inquiries we have recently received regarding the proper method for checking the operation of the pressure switch on a modulating furnace this letter explains how to best troubleshoot switches.

Recent Product Reports have raised the issue of nuisance limit tripping on our 90%+ furnaces.  Below is a list of known and proven actions to identify the root cause of -Fault Code Red 4 Flash "Open Limit Switch"

We had a few reports this past winter of the units listed above with noise issues entering and exiting defrost mode.  A change had previously been made to pin # 4 of the defrost control listed above which allowed to initiate at 26 degrees and terminate at 55 degrees, which resolved issues with the coil not completely defrosting.  At that time, the logic in the board was updated to cycle the compressor off 30 seconds upon an initiation of defrost, and 30 seconds upon a completion of the defrost period, eliminating the possibility of noise issues.  The compressor shutdown function is only active on pin #4.

Multiple field reports of erratic operations and/or nuisance fault codes have been reported.  Most of these are related to compromised electrical service and/or inadequate earth grounding.  Please use this letter as a tool on every start up and when troubleshooting.

AO Smith ECM motors are included in select model families of furnaces and air handlers. These are direct replacement for current Regal Beloit ECM Motors.

This letter addresses Rattling Condenser Fan Grilles

The original design of the drain pan used a round corner gasket on the back of the pan which matched the round corner laminate plates on the front of the secondary heat exchanger tubes.  However, due to high demand for production of these models, some laminate plates were produced with square corners which the rough corner gasket did not cover the edges properly. This could result in condensate leakage.

Reports of poor defrost performance and noisy compressor on the YZE and YZH heat pumps have initiated several changes to these product lines.  Engineering has verified that operations under extremely humid environments slightly above freezing, units can exhibit noisy compressor operations, incomplete, slow, or "lazy" reversing valve shift (defrost mode only), and incomplete or inadequate defrost in certain areas.

Product: TM8V, TMLV, & TM9V

In addition to the "no blower" operation issue addressed in ST-023-10, we have recently learned of a issue with the "Comfort Profile" feature of this control not operating as expected.  This service letter will recap all of the know issues with this control.

We are receiving reports of cracked drain pans on the 33' furnaces. Unlike the issue we experienced in 2008, we have not been able to determine a cause for these cracks.  While these cracks are occurring at a relatively low rate, we are putting a higher focus on the issue.