Operating instructions

6. Basic Troubleshooting

6.1 General Information

This section describes troubleshooting procedures for the TTC coolant heater.

Troubleshooting is normally limited to the isolation of defective components.

6.2 General Failure Symptoms

The following table lists possible failure symptoms.

Failure Symptom Probable Cause Remedy

Coolant heater

switches off

automatically

(Fault lockout)

No combustion after start

or automatic repeat start

Flame extinguishes during

operation

Heater overheats

Vehicle electrical system

voltage too low

Switch off heater momentarily and switch on once again

Check coolant lines for obstructions, closed valves and kinks.

Check coolant level. Allow heater to cool down, reset over heat

limiter, switch off heater momentarily and switch on once

again

Charge battery

Switch off heater momentarily and switch on once again

Heater expels black

fumes from exhaust

Combustion air and/or

exhaust ducting blocked

Check combustion and exhaust ducting for obstructions

Table 601: General Failure Symptoms

601

Thermo Top C (TTC) 6 Basic Troubleshooting

CAUTION

Troubleshooting requires profound knowledge about structure and theory of operation of the heater

components and may only be performed by skilled personnel.

Before troubleshooting, check for and eliminate these defects:

- blown fuses

- fuel supply (plugged fuel filter)

- corrosion on battery terminals, electrical wiring, connections and fuses

- loose contact on connectors

- wrong crimping on connectors

NOTE

After any correction of a defect a functional test has to be performed in the vehicle.