Checking a heating system

Part 1. Preparation and safety

Objective

• Check the heater system and hoses.

Personal safety

Whenever you perform a task in the workshop you must use personal protective clothing and equipment that is appropriate for the task and which conforms to your local safety regulations and policies. Among other items, this may include:

• Work clothing - such as coveralls and steel-capped footwear
• Eye protection - such as safety glasses and face masks
• Ear protection - such as earmuffs and earplugs
• Hand protection - such as rubber gloves and barrier cream
• Respiratory equipment - such as face masks and valved respirators

If you are not certain what is appropriate or required, ask your supervisor.

Safety check

• Be careful when you feel the hoses to check their condition, they may be hotter than you think!
• As you check the hoses, be careful not to touch any hot engine parts or any moving parts. Make sure you do not have any loose clothing when working around any moving part.
• Always make sure that you wear the appropriate personal protection equipment before starting the job. It is very easy to hurt yourself even when the most exhaustive protection measures are taken.
• Always ensure that your work area/environment is as safe as you can make it. Do not use damaged, broken or worn out workshop equipment.
• Always follow any manufacturer's instructions in relation to personal safety and prevention of damage to the vehicle you are working on.
• Make sure that you understand and observe all legislative and personal safety procedures when carrying out the following tasks. If you are unsure of what these are, ask your supervisor.

Points to note

• The heater system is basically very simple. It consists of a heater core, which is like a small radiator, through which the coolant circulates from the vehicle cooling system. When you turn on a heater fan, it draws air across this hot core, warming it up before it reaches the passenger compartment. This is a passive system, so unless it breaks down it needs very little attention.

• In some systems, a valve operated by a knob or lever inside the passenger compartment controls the flow of coolant through the heater core.

Part 2: Step-by-step instruction

1. Check the heater controls
   Check the controls inside the vehicle to make sure that they seem to be operating smoothly and are not broken or stuck.
2. Check the heater hoses
   Examine the hoses and clamps that connect the heater core to the cooling system of the engine. Make sure that they are not cracked or showing other signs of deterioration or corrosion. Also check to see that there are no visible leaks in the system.
3. Run the engine and check the core
   Run the engine for a few minutes until the coolant begins to warm up. Feel the hose entering the core and then the one leaving the core. They should both feel similarly warm. If the hose leaving the heater core is cooler than the one entering, then the core or one of the hose connections could be obstructed or clogged. Report this to your supervisor.
4. Check the heater is functioning correctly
   Switch the heater on to confirm that the fan is delivering warm air to the vehicle interior, and that all the controls are working correctly.