Hartzell Engine Techonology Sites

Service Documents

To ensure you have the best parts on the market, our service bulletins keep you in the loop about the latest product announcements, whether it’s a call for recommended service or upgrade.

October 23, 2024
Service Bulletin # 217
Aircraft Heater Alternate Blower Motor P/N 81251-1 Inspection. Affects Janitrol I-Series (IS) cabin heater assemblies with ventilating blower motor P/N 81251-1 installed.
April 12, 2021
Alert Service Bulletin #085
Heater Fuel Pump Leak Inspection and Replacement
September 17, 2019
Service Bulletin #082
Janitrol Aero heater combustion air blower inlet adapter high temperature tape inspection. Affects Inlet adapter P/N 84D38-(3, 4).      
August 28, 2018
Service Letter #076
South Wind Heater Inspection. Affects all South Wind (formerly Meggitt / Stewart-Warner) combustion heaters. Provides methods for terminating action to AD 2017-06-03.
March 2, 2018
Service Letter #060
CD Series Combustion Heater - Fuel Shroud & Hardware Supersedure. Introduces new fuel pump shroud for use on CD Series heaters.
August 28, 2017
Service Information Letter #A-144 Rev. 1
65C30 Sealed Control - Solenoid Valve & Clamp Replacement Affects any 65C30 Series unit when installing P/N 10C67-1 or P/N 81024 Solenoid Valve Assembly.
May 30, 2017
Alert Service Bulletin #071
Combustion Heater - CD14048 or CD14048-1 Heater Pressure Decay Test Requirement. Affects all CD14048 and CD14048-1 Cabin Heaters installed in Piper PA-31-350 Chieftain aircraft.
April 4, 2016
Service Letter #059
Combustion Heater - Improved Cycling Switch Installation Introduction of improved solid state cycling switches, P/N 81000 and 81001 to replace HET / Janitrol P/N 07D32 switch.
May 3, 2013
Service Bulletin #051
Replacement of P/N 69C13 Base in 65C30 Series Sealed Control Assembly.
August 22, 2012
Service Bulletin #A-101 Rev. G
Aircraft Heater Upgrade to I-Series.  Affects HET / Janitrol B-Series heaters.  Provides upgrade instructions and installation eligibility for HET I-Series Heaters.
March 27, 2008
Service Information Letter #A-129
Overheat Limit Switch Replacement - P/N ( )07D29 for Janitrol Aircraft Cabin Heaters.
February 9, 2007
Service Bulletin #025
Temporarily Disabling Janitrol B Series Aircraft Heaters (Supersedes Janitrol Aero SB 76).  Affects models B-1500, B-2030, B-2500, B-3040, B-3500, B-4050, and B-4500.
February 8, 2007
Service Bulletin #24
Welding of Combustion Tube in Janitrol B Series Aircraft Heaters (Supersedes Janitrol Aero SB73).  Affects Kelly Aerospace Power Systems models B-1500, B-2030, B-2500, B-3040, B-3500, B-4050, and B-4500.
January 31, 2007
Service Letter #023 B
Availability of Janitrol B Series Aircraft Heater Service & Overhaul Manuals P/N 24E25-1 & P/N 94E47. 
May 30, 2006
Service Information Letter #A-120
Improved Air Pressure Switch - 94E42.
December 20, 2004
Service Information Letter #A-110B
Recommended Service/Inspection for Model 91E93-1 & 91E92-1 Heater Fuel Pump.
March 21, 2003
Service Instruction #A-106 Rev. A
Recommended Time Between Overhaul (TBO) Period and Service Intervals for Extended Life (EL) Janitrol Heaters. Affects Janitrol Heater Models B2500, B3500, and B4500.
March 21, 2003
Service Instruction #A-105 Rev. B
Documentation Procedure For Installation Of New Factory Rebuilt Janitrol Heaters.
January 6, 2003
Service Bulletin #A-108A
New Regulator Valve Approved for Use in Hartzell Engine Technologies B4050 & B4500 Series Heaters Installed in Piper PA-31-350.
September 6, 2002
Service Bulletin #A-107A
Inspection of Fuel Regulator Shutoff Valve as used with Kelly Aerospace Combustion Heaters, Models B-1500 through B-4500.
March 1, 2001
Service Bulletin #A-104 Rev. B
Janitrol B-Series Aircraft Heaters Combustion Air & Ventilation Air Blower Motors. Part supersedure information.
October 1, 1998
Service Bulletin #A-103 Rev. A
Janitrol B-Series Aircraft Heaters - 42D36 Combustion Air Pressure Switch. Supersedes SB #A-102.  Obsoletes P/N 42D36 replaced by P/N 94E42.