Diesel generator in winter: 8 checks before the deep cold

In Quebec, outages often hit at the worst time: ice storms, snowstorms, high winds. That is exactly when a diesel generator must start on the first try. Cold makes everything harder: fuel thickens, the battery loses strength and oil flows less easily.

Here are the 8 points to check from late October, before the first deep cold.

1. Fuel: switch to winter diesel

Regular diesel contains paraffin that solidifies as the temperature drops. The fuel turns cloudy and then clogs the filter: the engine stalls or will not start.

• Use winter diesel, sold by fuel suppliers from the fall.
• If summer diesel remains in the tank, ask your supplier for advice (additive or dilution with winter diesel).
• Keep the tank full: less air means less condensation, so less water in the fuel.

2. Fuel filter and water separator

Water in diesel freezes and blocks the lines. Before winter, drain the water separator and replace the fuel filter if it is close to its change interval: a loaded filter clogs faster when diesel thickens. Genuine Perkins filters are available in our filter shop (in French).

3. Block heater

The block heater keeps the coolant warm, so the engine starts more easily and wears less at start-up. All our Perkins generators are delivered with a block heater.

• Check that it is plugged in and heating: the engine block should feel warm.
• Inspect the cord and plug, often damaged by frost or rodents.

4. Battery and charger

In the cold, a battery delivers less energy while the engine needs more to crank. It is the leading cause of winter no-starts.

• Clean the terminals and tighten the connections.
• Check that the battery charger works (indicator light, voltage on the controller).
• Have a battery older than 3 years load-tested.

5. Antifreeze

Coolant that is too diluted can freeze and damage the engine. Check the level with the engine cold and have the freeze protection measured: it must cover the coldest temperatures in your area. Our generators are delivered with the cooling system prepared with Prestone antifreeze.

6. Engine oil

Oil that is too thick flows poorly at start-up, when the engine needs it most. Check the level and, if an oil change is coming up, do it before winter with an oil suited to the cold, following Perkins recommendations for your model.

7. Air intake, exhaust and enclosure

• Clear the air intakes and exhaust outlet: an outlet blocked by snow can push exhaust gases toward the building.
• Check that the enclosure doors close properly and that access stays clear for service.

8. A load test before the storms

Starting the generator for a few minutes with no load is not enough. A diesel that often runs unloaded builds up unburned fuel in the exhaust (known as wet stacking).

• Run a test with a real load: let the automatic transfer switch move the building onto the generator, or use a load bank.
• Record hours, voltage, frequency and controller alarms.
• Check that the transfer switch transfers and returns correctly.

Printable checklist