2900 Selma Highway, Montgomery AL 36108 USA
PH: +1.334.386.5400 (option 2) FAX: +1.334.386.5450 WEB: www.hartzell.aero
Page | 37
MM10001
Dated 1/1/08
Rev L dated 5/21/15
11 TROUBLESHOOTING
The following lists service troubles and suggested remedies. It will assist in locating and correcting the
cause of faulty operation. Some of the information is based upon the use of optional and separately
provided components.
11.1 TROUBLESHOOTING - HEAT QUICK CHECK
Introduction: Every heating system requires 3 key components to achieve proper operation. They
must have combustion air, ignition, and fuel. If your heater is not working, one or more of these
elements is deficient. By finding out which of these three elements is lacking, the problem can be
determined in just a few minutes. In order to complete a thorough analysis of heaters operation,
three pieces of test equipment will be needed. A volt meter or light for checking rated voltage, a
quality fuel pressure gauge and a 0-500° temperature gauge.
Preparation: Remove access panels to heater area. With assistance in the cockpit, perform the
following initial three-step inspection.
• Combustion air: Generally 1/2" to 8” inches of water is sufficient. This does not need to be
measured with a water manometer; simply wave your hand a couple inches under the exhaust.
Airflow from the exhaust should be steady, and the pressure output should feel similar to a
standard hair dryer. Keep in mind that in flight, ram air supplements the blower to provide
additional combustion air. Unfortunately ram air also prematurely will wear out older heater
motors as the blowers continue to pin-wheel even with the heater off.
• Ignition: All Janitrol B-series and S-series igniter plugs should be replaced and have their gap
set every two years. This should fix most of your problems. If not, remove the lead from the
spark plug and using rubber handled pliers (very important if you like your mechanic) and
hold the lead end approx. 1/4” from a ground. Have someone turn the heater on and verify
that the spark jumps at least 1/4”, is consistent, blue in color and strong. Another simple way
to check for ignition, move close to the exhaust; see if you notice the sound of a constant,
strong spark. It should sound kind of like a wet hornet trying to get out. Use caution with this
method though as the heater could suddenly light off. You can usually identify the mechanic
who has done this procedure incorrectly by the resultant lack of facial hair.
• Fuel: Fuel pressure is the neglected step child of the combustion heater. Annually ensuring
proper fuel pressure to your heater can add years to its life (and many times your marriage)
because overall reliability will definitely improve. Most Janitrol B series and Hartzell Engine
Technologies LLC heaters require 6.5-8 PSI (turbine aircraft 100+5-0 PSI). South Wind
8240-8472 series must have 22 PSI or above. It’s relatively simple to “T” in a quality fuel
pressure gauge just upstream from the heaters fuel solenoid, and take a reading while the
heater is running.
To Next Page
Loading...