Cummins RS25 Generator Review

I recently installed a Cummins RS25 25kW generator for our house and wanted to provide folks with some info.

For those that want a good deal on maintenance items for this thing - the genuine Onan part #'s for spark plugs are A044H806, and oil filters are A044D820. However, these are very expensive parts! I received some that I ordered today, and the spark plug is just an NGK BKR6E-11 plug, and the oil filter is a Fleet Guard LF3537. You can cross reference the oil filter online and find better deals than just buying Cummins parts that are re-branded.

[jerkimerjames]

FYI, I was one of several early (2010 to 2011) designers on this project. My area responsibility was engine design (FWH and integration with all other areas. Unfortunately, I fell ill with leukemia before the project finished. Several dozens of people worked on this design and the various nodes and options over the years. I maintain relationships to this day with a few who still work at Cummins. Having survived to stumble upon to see this video, which helps give me solace in the work I had done for decades. Helping create products used all around the world. Great review. Please follow up with anything you learn over the years.

[sonosource]

We are in Texas and the Cummins RS36 whole house generator saved our lives, when the entire state power grid went down 2021 winter, it switched over automatically, ran quietly and we never went without electricity. Ours runs on natural gas and ran our 6, 000 sq’ house, pool house and pool for 4 days straight. When we got our gas bill and it was under $200.00. This was the best money we ever spent-had it installed by AAGenPro fall 2020. Had to wait 3 months for installation because of manufacture back order on these systems. If you live in a hurricane zone-this is a must.

[canislupis]

I had a 30KW Cummins 1800 rpm installed. It is very quiet when running. I went over sized because the cost from 20kw to 30KW was so small, I could not justify not doing it. I had mine installed by a contractor and all told it was about $23K. I selected Cummins because With my job with the phone company I was a cable splicer and we used Cummins Gennys to run our power needs for working in manholes and they performed well. Our home is a bungalow with 4 BR and 2 bathrooms, about 2000 square feet. We have a detached garage with two fridges and full freezer. We have an 18, 500 gallon pool. It’s very hot where I live in Texas and our power goes out more than I like. I’m glad I went with an oversized unit just in case. Better to have more than to be just on the line. When our power goes out I want my whole house running. Central AC, tv, washer and drier, garage, pool especially. Everything. I can stand right next to it when running and talk on my cell phone. Although it performs well I had bad luck in the beginning with two parts failures that were covered under warranty, but our contractor became very difficult to deal with and they are more than an hour drive away. We found someone much closer and they have been terrific so far.

[justineaton]

Finally got mine installed, awoke this morning to find it pitch black out everywhere except for my house. I couldn't even hear it running, until I went outside to check. I wish I could post a picture to show the final install I'm quite happy with it.

[VDUBZ]

Great installation. I commission these and work for Cummins and don’t see professionals do it as neat as you did if you truly did it yourself. Those are great units. Never had anything serious to repair on them. Very quiet even with the doors open. FYI when you exercise it let it run for anything longer than 15 minutes. They need to get hot. Short runs doesn’t let the oil get up to temp and they wind up with condensation in the oil. If you can run it with load even better. They like to be loaded.

[nogeek]

Hey Travis,
We just went through Hurricane IDA in SE Louisiana. The Cummins RS25 on propane ran for 114 hours nonstop. Max load was measured at 12, 000 watts and it
worked perfectly the whole time. My 500 gallon propane tank went from 80% to 50% in the 114 hours of running. I am very pleased with the Cummins. Now it's time
to change the oil and filter and get ready for the next one. This generator was new as of Oct 2020.
Pat Darby
Covington, LA

[Dqalex]

Fantastic job. I wish I could have done it myself too and saved money. I went with the Kohler 30RCL. for my home in Florida. I have a Kohler 60 RCL natural gas at my store for backup. You can't beat an 1800 RPM generator. I agree with you 100% on going with the liquid cool 1800 RPM over the air cool 3600 RPM screamer generators. . Another good thing about having a backup generator in Florida is you can also run the AC in your home to keep the humidity down after a storm if the power is out.

[kermit]

Just waiting for this video to blow up and appear in everones recommendation just like it did mine

[HHIMgary]

Great job Travis. I work on these units for Cummins and you cover all the important things. One of the things I have seen customers do is unplug the coolant heater because it does not get that cold here. I have to explain to them that the coolant heater is not for cold weather, it is to keep the engine warm so that if it has to start up and assume a load it does not have to do that cold. Sometimes when an engine starts cold it will not take a load, it will surge up and down in RPM until it warms up. Anyway, I thought I would throw that in. Great video.

[hurtwj]

I purchase a Cummins 20KW for a 6 bed rm 4000 sqft home and it never missed a beat. I was told by a Generac dealer that I would need a larger unit. The Cummins dealer put this in and said the 25KW was over kill because no one ever has everything on at once in a home. I must say that it has came on a minimum of 6 times this year, with the AC, clothe washer and dryer on it ran perfectly. My family doesn't change anything when it comes on. We do have a gas a stove so I do not use electric for that. I love my unit. Also it was 9, 000$ for my unit and installation which was also cheaper than the Generac quote by 2K. Located in Augusta Georgia area.

[justineaton]

I'm in the process of installing the same RS25 liquid cooled unit . I have the concrete pad about 25' away from my house, I don't want to hear or see it.
I'm also doing all of the install, Really good video!

[hollywinsman]

Travis, this was the most comprehensive videos that I have ever seen. You obviously have worked with electricity before. This would not be for me. Love Cummins diesel trucks and they provide the same service with their generators. Very nicely done. Thank

[willienolegs]

Thanks for taking the time to show this vid. Had a Generac but was not impressed with it. The Cummins. Sounds like the thing to get. 73

[stiljustdean]

nice review, Travis. Thank you for sharing. This is size I'm looking at and comparing. It was nice to see your photos and gain a better understanding of the product.

[mikeconroy]

First class installation! I sold all manner of gensets for many years and the worst installations were usually done by contractors who said they had "installed 100's of these". That being said, on the price factor, one should probably consider the installed cost to be about double what the generator and ats cost. And that's only if everything is in close proximity to each other (elect service, gas service, ats and gen). Most electricians don't like these small jobs because they have to sub out the gas, working with individuals' schedules and nuances is harder to deal with and having to go back and wait on inspectors is wasted time. On a large building jobsite, those factors go away and there's other stuff people can do on site. Also, a perfect homesite needs to look perfect when you leave where a commercial jobsite will have other trades that make things pretty after your long gone.

[tristenklein]

Excellent review Travis and thanks we are looking to install a new stand by generator and I don’t understand why we see so many of these generators no matter the brand not installed on a concrete slab as they do in all commercial buildings it by far seems to me it would not only stabilize the unit from the vibrations caused during operations but also keep the unit raised and out of the dirt, dust, water and mud thus keeping the unit cleaner and cooler during operations. We have both our AC units mounted on a concrete slab and will do the same once we install the new generator and yes it will be the Cummings Onan after reviewing many brands and having a Generic and familiarity with Cummings engines via our construction equipment running many various sizes of Cummings Diesels and the ease of maintenance and repair on them. 👍👍

[debsdigest]

Thank you for this video! I live in the Mount Dora area, and it's nice to see a review from someone in our area. I probably will have questions for you. :)

[pipeliner]

Excellent!! Report. Thank you. I'm looking. I totally agree with the length of run time. Hurricanes knock power out for months sometimes. Those 2 cylinder lawn engines won't cut it. Great video!!

[av-mike]

Perfect video! I live in the same city and have the same split phase panel setup as you, so this video was EXACTLY what I was looking for. Thanks!

[joelflowers]

Fantastic video review. In most (if not all) videos that review standby generators, the reviewer does not state how many A/C units, the size of the A/C units, or the wattage of their oven. All of those helped me make my decision to go with the Cummins RS25 over the other manufacturers and air cooled. Thank you!!!!