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Stationary heater (STH) diagnosis, troubleshooting - AD83.70-P-5001A

MODEL 129 as of 1.6.97 with CODE (228) stationary heater 

IMPORTANT Stationary heater (STH) diagnosis, advanced information   AD83.70-P-2001A 
IMPORTANT Stationary heater unit, location of components   GF83.70-P-0006-03B 
  Troubleshooting     
Complaint  Possible cause  Note  Remedy 
It is not possible to start the stationary heater unit
  • Undervoltage
   Charge battery
 
  • Malfunction lock-out due to previous overheating
   See Hand-Held Tester (HHT)
 
  • Stationary heater timer (N34)
   AD83.70-P-6001-03A 
 
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Malfunction shut-down at start of heater operation with heater unit run-on (approx. 120 seconds) of combustion air blower (A6m2) and circulating pump (A6m1) without repeat start.
  • Glow pin (A6r2) in its flame monitor function
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Malfunction shut-down at start of heater operation with heater unit run-on (approx. 120 seconds) of combustion air blower (A6m2) and circulating pump (A6m1) after an unsuccessful repeat start initiated automatically.
  • Stationary heater fuel metering pump (Y23)
  • Combustion air blower (A6m2)
  • Glow pin (A6r2) in its flame monitor function
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Combustion starts during the preglow time
  • Remains of fuel in combustion chamber due to unsuccessful attempts at starting
   Allow heater unit to operate for 10 minutes
 
  • Internal leakage in fuel metering pump (Y23)
   AD83.70-P-7000-02A 
Vehicle heater blower does not operate at a coolant temperature > 30°C
  • Blower motor (M2)
   AD83.70-P-6001-09A 
 
  • Actuation of air conditioning (automatic) control and operating system
   AD83.70-P-6001-08A 
Stationary heater/heater booster unit (A6) does not switch to full load operation despite a requirement for heat
  • Combustion air blower (A6m2)
  • Stationary heater fuel metering pump (Y23)
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Despite a requirement for heat, the stationary heater/heater booster unit (A6) goes into the combustion interval within approx. 10 minutes during trouble-free heater mode.
  • Coolant level or routing of coolant lines
   Check coolant level, if necessary replenish and/ or bleed coolant circuit.
 
  • Actuation of blower motor (M2)
   Check coolant lines for kinks and pinching
 
  • Blower motor (M2)
   AD83.70-P-6001-08A 
 
  • Circulating pump (A6m1)
   AD83.70-P-6001-09A 
 
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Heat output too low
  • Setting of vehicle heater
   Increase temperature setting
 
  • Combustion air inlet on stationary heater/heater booster unit (A6)
   Check combustion air inlet for contamination and clean if necessary Check coolant level and if necessary replenish and/ or bleed coolant circuit.
 
  • Coolant level or routing of coolant lines
   Check coolant lines for kinks and pinching.
 
  • Heater circuit thermostat
   Check function
 
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Despite a reduced requirement for heat, stationary heater/heater booster unit (A6) is not switched to part load operation or to the combustion interval.
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Escape of combustion exhaust gases which are sooty or form dense smoke
  • Combustion air inlet at stationary heater/heater booster unit (A6)
   Check combustion air inlet for contamination and if necessary clean
 
  • Exhaust emissions value too high
    
 
  • Fuel delivery quantity
   Check and adjust exhaust emissions value with HHT
 
  • Combustion air blower (A6m2)
   AD83.70-P-7000-01A 
 
  • Stationary heater/heater booster control module (A6n1)
   Check all actual values with HHT
Gray/white combustion exhaust gases (white smoke)
  • Exhaust emissions value too low
   Check and adjust exhaust emissions value with HHT
Loss of coolant
Gray/white combustion exhaust gases (white smoke)
Exhaust gas odor extremely sweet
  • Stationary heater/heater booster unit (A6)
   Check stationary heater/ heater booster unit (A6) for external leaks and if necessary replace heater unit.
Loss of fuel or fuel odor
  • Fuel supply of stationary heater unit leaks
   Localize leakage point, check fuel metering pump, fuel supply lines, connections and stationary heater unit for fuel leaks and if necessary seal leakage point or replace component
Heater operation cannot be terminated manually
  • Stationary heater timer (N34)
   AD83.70-P-6001-03A 
It is not possible to test the stationary heater components with the HHT
No communication between HHT and stationary heater/heater booster control module (A6n1)
  • Cables, cable connections
  • Voltage supply
  • Diagnostic cable
   Check and if necessary replace
AD83.70-P-6001-01A 
AD83.70-P-6001-02A 
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