Most generator observations arrive without a verdict attached. The unit sounded different during its exercise cycle, or a light is showing that was not showing before, and there is no obvious way to tell whether that is worth a phone call or worth forgetting.
Who this helps
An owner who has noticed something — a sound, a light, a smell, a message, a change in how it runs — that is not obviously a breakdown.
When to read it
Read this before deciding it is probably nothing. Deciding urgency is a different question from deciding what is wrong, and only the first one is yours to make.
What you can decide afterwards
How urgently an observation needs acting on: today, at the next scheduled service, or by recording it and watching.
Quick answer
A short list of observations means stop and get help today regardless of anything else: any smell of gas, smoke, a burning smell, sparking, standing water around the equipment, or a carbon-monoxide alarm sounding. Nothing on that list waits. Outside it, the question is not whether the observation is serious — you cannot determine that — but whether it is documented. Record what you saw, when, and under what conditions, then raise it at the next service unless it repeats, worsens, or the unit fails to start when it should.
What this chapter can help you determine
Which of three responses an observation warrants, and what recording it actually means if the answer is to watch.
The observations that mean act today, without qualification.
What watching something actually involves, so it is evidence rather than a memory.
What belongs on the list for a scheduled visit.
Why urgency and cause are separate questions.
Three responses, and how to tell them apart
Act today, whatever else is true
A short, non-negotiable list. These are not generator questions in the first instance; they are gas, fire, or electrical matters, and they are routed accordingly.
This points here when:
There is any smell of gas near the property.
There is smoke, a burning smell, or visible sparking.
A carbon-monoxide alarm has sounded.
Any part of the installation is standing in water.
The equipment is visibly damaged after weather or impact.
If this is the wrong call: Treating one of these as something to watch. Leave the area and contact the utility or emergency services from elsewhere first; the generator company comes afterwards.
Record it and watch
The observation goes into a written record with enough detail to be evidence later. Watching is a documentation activity, not a decision that the observation is harmless.
This points here when:
Something sounded, looked, or behaved differently, and it is not on the act-today list.
It happened once, and the unit otherwise ran as expected.
The controller showed nothing, or showed something that cleared.
You cannot yet say whether it is a change or something long-standing you only just noticed.
If this is the wrong call: Watching without recording, which produces a vague recollection rather than a sequence — and a technician can do nothing with a recollection.
Put it on the list for the next scheduled visit
The observation is documented and raised when someone qualified is already coming, rather than triggering a visit of its own.
This points here when:
A service visit is already due or scheduled.
The observation has been recorded and has not repeated or worsened.
The unit has continued to start and run as expected.
The question is one a technician can answer while doing other work.
If this is the wrong call: Deferring something that was repeating or worsening. If either is true, it has left this branch and belongs in an earlier one.
What you probably already know
What you noticed, roughly, and roughly when.
Whether the unit has been serviced recently.
Whether this is the first time.
Whether a service visit is already due.
What is commonly still unknown at this point
Whether what you noticed is a fault, normal behaviour, or something in between.
Whether it has been happening for longer than you have been noticing it.
Whether the exercise cycle has been completing while nobody watched.
What the manufacturer's schedule says is due for this unit and this interval.
Information to gather
What you observed, in the words you would use to describe it aloud.
The date and time, and what the weather and the property were doing.
Whether the unit was exercising, running under load, or idle.
Anything shown on the controller, copied exactly rather than summarised.
Whether it repeated, and if so how the second occurrence differed.
Questions worth asking yourself first
Is any part of this on the act-today list? That question comes before every other one.
Has this happened before, or is this the first time I have noticed it?
Did the unit still start and run when it was supposed to?
Is a service visit already due, and when?
If a technician asked me to describe this, could I do it from a record rather than from memory?
Has anything at the property changed recently that coincides with it?
When this does not apply
The unit has failed outright, or did not start when it was needed. That is a service call, not a triage question.
A technician has already examined it and given a finding.
A repair has been quoted and the question is whether to proceed.
Anything on the act-today list is present, in which case there is no triage to do.
What would change the decision
It repeats. A second occurrence moves an observation out of the watch branch.
It worsens, or the interval between occurrences shortens.
The unit fails to start, or does not complete an exercise cycle.
Anything on the act-today list appears alongside it.
A household member depends on powered equipment, which lowers the threshold for acting.
What requires a qualified professional
Deciding urgency is yours; deciding cause is not. Nothing here identifies what an observation means, and a page that claimed to would be guessing about equipment it cannot see.
Do not open the enclosure or any panel to investigate. The equipment can start automatically and involves utility-voltage electricity and fuel gas.
If a household member depends on powered equipment, treat the threshold for acting as lower than this page describes, and say so when you call.
Where any doubt remains after reading this, the correct answer is to ask someone qualified rather than to settle it yourself.
What this chapter cannot tell you
Whether what you noticed is a fault.
What is causing it.
Whether the unit is safe to continue running.
Whether it will get worse.
Deliberately out of scope here:
Whether what you noticed is a fault. This page cannot tell you and does not try.
What is causing it.
Any judgement that an observation is harmless.
How long the equipment can continue in this condition.
Common questions
The generator sounded different during its weekly test. Is that a problem?
This page cannot tell you, and neither can any page. What it can tell you is that a one-off difference with no other symptoms is normally a record-and-watch item, and that it stops being one if it repeats, worsens, or the unit fails to complete a cycle.
What does it actually mean to monitor something?
Writing down what you observed, when, and under what conditions, then checking whether it recurs. Monitoring without a record produces a vague impression a technician cannot work from, which is the same as not monitoring.
How long should I watch something before calling?
There is no interval that applies to every observation, and inventing one would be worse than useless. What moves it out of watching is an event, not elapsed time: it repeats, it worsens, the unit fails to start, or something on the act-today list appears.
A warning light is on but the generator still runs. Can it wait?
Record exactly what is showing before anything else, since that display is often the most useful information available. Whether it can wait depends on what the indicator means for your model, which is a question for your manual or a technician rather than for this page.
Bottom line
Urgency and cause are separate questions, and only urgency is yours to answer. Clear the act-today list first, because nothing on it waits. Everything else gets written down properly — what, when, under what conditions — and either raised at the next visit or escalated the moment it repeats or worsens. A recorded observation is evidence; a remembered one is not.
Safety-sensitive content. Last reviewed .
What to do next
The next decision is What to do before calling for generator service — Whether this needs an emergency response or a scheduled visit, and what to have in front of you when you make the call.
Repair or replace your standby generator — Whether this generator warrants a repair conversation or a replacement conversation when you next speak to a qualified technician.
what the exercise cycle does and does not prove — Most observations in this chapter surface during the weekly test, and that page cites what the manufacturer says the cycle actually demonstrates.
whether waiting has a coverage cost — Waiting carries a cost that is easy to overlook, because coverage terms run on their own clock regardless of how the fault develops. Establishing whether this is covered belongs inside the decision about how long to watch it, not after that window has closed.