22kw unit shut down during power outage. Screen shows low oil pressure, code 1300. Plenty of clean oil showing on dipstick. I have a filter and new oil and may just change it later today. Owners manual just suggest checking oil level, after that call service man. unit installed April of 2015.
Any experts know of what to check next?This message has been edited. Last edited by: gjgalligan,
Integrity is doing the right thing, even when nobody is looking.
June 27, 2026, 07:08 AM
mrvmax
I do not have a Generac (mine is a Briggs and Stratton) but I would check the oil pressure switch to make sure the wiring is ok. There is probably a video online that shows how to check the switch itself. I assume that the pressure switch sensed low oil pressure and shut it down.
June 27, 2026, 07:14 AM
trapper189
Bad oil pressure switch? If you check you oil pressure and it’s good, then the pressure switch is probably bad.
If you check your oil pressure and it’s bad, then you got problems ranging from broken teeth on the plastic gear for the oil pump to clogged oil passages from those broken teeth to spun bearing from the bearing not getting enough oil due to oil passages being clogged from the plastic teeth.
How did it run? If it ran like crap, you probably really do have low oil pressure and should just call the man.
Otherwise, here’s how you check the oil pressure, Harbor Freight has an oil pressure test gauge for $35:
June 27, 2026, 04:03 PM
sigarmsp226
And this is why I love this forum. Friends helping friends.
June 27, 2026, 05:09 PM
HRK
Bet is the Oil pressure switch is bad, so it's not allowing the unit to run.
You can take the wires off and connect them together, jumping the circuit around the switch, which effectively mimics the switch working properly. It's a basic test method vs just swapping the switch and the guy does that in the video at 2:30ish...
Of course if there really is an oil problem then you need to shut it down, but that should let it run until the power is back on.
June 27, 2026, 05:48 PM
Ripley
Their oil pressure switches are cheap and easy to replace so there's that.
Set the controls for the heart of the Sun.
June 28, 2026, 07:00 AM
gjgalligan
I am just not comfortable with running it without a sensor/switch. Amazon says the new switch will be here Monday $12.99 (+sales tax}. I thought about buying a pressure testing gauge kit but at my age it would probably be a one time use item. I have too much stuff in the workshop now. I changed oil & filter and started it but it shut down again for low oil pressure. Did the plugs while I was at it.
Integrity is doing the right thing, even when nobody is looking.
June 28, 2026, 08:04 AM
Ripley
Have you tried resetting the control system? There should be several vids out there, maybe a slightly different procedure depending on your unit.
Set the controls for the heart of the Sun.
June 29, 2026, 12:02 PM
gjgalligan
New oil pressure sensor installed, unit running great. I did miss noticing the new one on Amazon had ring type terminals while my unit had spade type connections. A couple of short jumper wires with the proper connectors only took a few minutes. I even was able color match the wire colors on the jumpers. Only repair needed in 11 years so I will say it's a good quality product!
Integrity is doing the right thing, even when nobody is looking.
June 29, 2026, 12:52 PM
HRK
Failed oil pressure sending units are a pretty common problem on generators.
June 29, 2026, 04:16 PM
mrvmax
Glad you got it going on your own.
June 29, 2026, 04:38 PM
Blue Dog
Good job man
June 29, 2026, 05:45 PM
armored
Now, buy a spare.
June 29, 2026, 06:27 PM
gjgalligan
Suppose to be in the upper 90s this week with heat index 100+. My wife has asthma and need AC, had a new one installed last Thursday. But we all know Murphy, I needed to make sure I have power backup in case of another power outage.
Integrity is doing the right thing, even when nobody is looking.
June 29, 2026, 09:01 PM
trapper189
You probably know this, but you are supposed let it cool down for 30 mInutes every 24 hours, check the oil, and I believe oil changes are every 200 hours. There's a valve adjustment at some point as well. I learned about checking the oil every 24 hours after the power was out for 3 weeks at our MI home due to the ice storm. We were not there and while reading the manual to verify the oil change interval, I came across the cool down thing.
Fortunately, everything was fine in our case. Since we weren't there, the only loads on the generators were the air handlers and sump pumps, plus it was cold outside so I don't believe there was a heat issue. For oil, I use Castrol 5w-30 in the gold jug that's supposed to be good for 20,000 miles. It looked new and the level was fine when I got up there after the storm.
Now down in Floroda after a hurricane could be different. A member of our church asked me if I could take a look at her generator after Ian because she couldn't a get tech out because shockingly, they were extremely busy. She ran it 24/7 for 8 days under load until her propane tanks ran out. The oil came out looking like honey and just about as thick.
June 29, 2026, 10:15 PM
jimmy123x
quote:
Originally posted by trapper189: You probably know this, but you are supposed let it cool down for 30 mInutes every 24 hours, check the oil, and I believe oil changes are every 200 hours. There's a valve adjustment at some point as well. I learned about checking the oil every 24 hours after the power was out for 3 weeks at our MI home due to the ice storm. We were not there and while reading the manual to verify the oil change interval, I came across the cool down thing.
Fortunately, everything was fine in our case. Since we weren't there, the only loads on the generators were the air handlers and sump pumps, plus it was cold outside so I don't believe there was a heat issue. For oil, I use Castrol 5w-30 in the gold jug that's supposed to be good for 20,000 miles. It looked new and the level was fine when I got up there after the storm.
Now down in Floroda after a hurricane could be different. A member of our church asked me if I could take a look at her generator after Ian because she couldn't a get tech out because shockingly, they were extremely busy. She ran it 24/7 for 8 days under load until her propane tanks ran out. The oil came out looking like honey and just about as thick.
I'd suggest every 2 days and if no oil usage every third day. We run generators non-stop for weeks sometimes. Every 2-3 days will start the other generator and shut down the 1 and check fluids. Constant rpm and constant temperature is best for less engine wear. Generators usually don't burn oil (to where you need to add) because they run at a constant RPM (usually 1800 RPMS for diesel, 3600RPMS for gas/propane but a few 1800 rpms. They shouldn't need to "cool down" for any reason as they shouldn't overheat at all.
8 days is the normal oil change interval for most whole house generators (200 hours +/-)
June 29, 2026, 11:25 PM
trapper189
Jimmy, it's in the Generac manual. These $6k air-cooled 22kW backup generators are not what you are running on the boats you manage, are they?
June 30, 2026, 09:13 PM
jimmy123x
quote:
Originally posted by trapper189: Jimmy, it's in the Generac manual. These $6k air-cooled 22kW backup generators are not what you are running on the boats you manage, are they?
They are not, but I am involved with a few luxury houses for the yacht owners that have Generacs. I can assure you that not a single one of them has read the owners manual, nor even know where it is.
Not sure what a cool down period would accomplish considering the thing has been running 23.5 hours straight, they run at the same RPM the entire time, only difference is how much fuel is going through them at a given time (based on load). I believe it's more of a check the oil every 24 hours, cover their behind thing. Air cooled can use a little oil if loaded down pretty heavy. But, follow the manual if it's in there. Water cooled is much better overall.