Generators rarely fail without warning. For months before a standby generator will fail, it shows signs, quietly telling somebody that something is wrong in a room nobody visits.
Here are five signs your standby generator will fail, and each one is worth knowing. None of them requires any technical training to spot — if you can read a logbook and look at an exhaust, you can check all five this afternoon.
This is the biggest one, and it is not really about the machine at all.
If there is no maintenance log, no inspection reports and no service contract, then whatever condition the generator is in, nobody knows what it is. Buildings change hands, facility managers move on, and generators get forgotten for years at a time while everyone assumes somebody else is handling it.
Get a full inspection and a written condition report. Then you have a starting point.
Diesel does not keep well. In storage it separates, absorbs water from the air, grows microbial contamination and forms sludge that settles at the bottom of the tank — right where the fuel pickup sits.
A generator running on degraded fuel will often start and idle perfectly. The trouble begins when it runs for hours under load and draws hard from the bottom of the tank. Filters block, and the engine shuts down.
Have the fuel tested. If it is contaminated, fuel polishing cleans the fuel and the tank without you having to dispose of the whole lot.
Classic wet stacking. It comes from running a diesel engine repeatedly at little or no load, so it never gets hot enough to burn its fuel properly. Unburned fuel and carbon build up in the exhaust.
It gets worse over time and it costs you power, fuel and engine life.
A proper load bank test brings the engine to full operating temperature and burns the deposits off. If it has been going on for a long time, some cleaning of the exhaust system may be needed too.
A very large share of standby generator failures come down to the starting system, and usually the battery.
If the batteries keep going flat, or keep getting replaced, the battery is probably not the actual problem. A failing charger, a parasitic drain, corroded connections or a charging system that is not keeping up will all kill a healthy battery repeatedly.
Stop replacing batteries and have the charging system tested properly.
A monthly exercise run with nothing connected proves the engine starts. It does not prove the machine can carry your building.
If your generator has only ever been exercised at no load, you genuinely do not know whether it will do its job. Plenty of generators that start perfectly every month fail within the first hour of a real outage.
Book an annual load bank test. It is the only test that answers the question that matters.
Small oversights. Major blackouts. These five common generator defects account for the vast majority of emergency service calls—and every single one is cheap to fix and expensive to ignore. Swapping out a neglected filter takes minutes. Relying on a dead generator in a long-term care home during a winter storm is a disaster.
If any of this sounds familiar, GenWorx can inspect your generator and tell you exactly where it stands.
Weekly, monthly, semi-annual and annual — and who is responsible.
A generator that starts is not a generator that works.
What happens inside the tank, and how to prevent it.
