Generac or Koehler whole house generator?

[grsthegreat]

When i installed my unit, i fluctuated between the 22 kw air cooled and 22 kw liquid cooled unit. At the time the 1800 rpm liquid cooled unit was a real tempting draw.

But i realized our amount and lengths of outages didnt justify the additional $4,000 expense. Plus the unit was 2x as large. And alot more complicated to work on.

Its just plain frustrating to get a service call on a liquid cooled unit that shut down because a radiator sensor failed. There are so many sensors on these units, like a modern gas or diesel car. I like plain old air cooled units. Way, way less false alarms.

I used to maintain alot more large gas fueled liquid cooled units, but stopped doing them when maintaining inventory and training requirements got too expensive on the bottom line. The few i do now are for long time clients only.

I do suggest that anyone considerings a whole house unit do some real load calcs. I have seen too many people buy a , say 15 kw honeywell (generac) unit from costco and want me to install it on their 8,000 sq foot all electric house. Aint going to cut it.

The Smart Management Modules (SMM) that generac uses to shed loads work great, to a point. But its far better to size a unit for real load.

A 13 kw unit that has to run max output to power the house will eat more fuel than a 26 kw running at half load.

I also recommend a Soft Starter on large AC or Heat Pumps. They take out about 60% of the inrush start up load from the appliance. On my own 5 ton ac unit, all the lights in the house would momentarily dim when unit fired off. And really lug down the generator. After installing the soft starter, generator doesnt even hickup and no more lights dimming.

 

[BleedingOrange]

For the cost of these larger units, I,,m surprised, and dis-appointed that these larger units do not have a transfer system that will power up the complete panel. I have a 11K unit that I manually switch into service, and it allows us to carry on our day completely normal. The only thing I would like to add is a light on the incoming side of the normal power feed so I know the utility power is back on, but it isn,t a big deal, cause one of our neighbours calls us when her back-up system shuts off and regular power is restored.

 

[Cub 7275]

I didn't read through all the replies since I read the thread yesterday so I apologize if this has been covered already. When I looked into the popular whole house generators I got disgusted. There are surprises, such as Kohler units have to have the oil checked every 8 hours or they can void your warranty! Generac says the following: "When your generator runs continuously for 24 hours, shutting it down for at least 30 minutes is essential. This downtime allows the unit to rest, oil levels to be checked, and a visual inspection to be conducted. Performing these steps proactively can help catch any potential issues early and maintain the longevity and reliability of your generator."
They can tell if the unit runs for more than the maximum continuous hours so it has to be shut down and restarted before the maximum time interval is reached. Generac's "free" extended warranty requires a "qualified" tech to service it regularly, which, of course, isn't free and increases the total cost of ownership vs doing your own maintenance.

Quality whole house generators that are rated to run continuously are big money, which is hard to justify for emergency power, so we recently bought another portable. As nice as it would be to have a whole house, fully automatic unit, I can't imaging powering everything down and then shutting down the genny to check the oil level every 8 hours for two weeks straight (the longest outage so far). Even having to do that once a day would be annoying. And if we were away from home when the power went out and the generator ran too long, the manufacturer just got an excuse to void the warranty. No thanks.

If you want a warranty, do not assume anything and read ALL the fine print before purchasing any whole house unit. Best to choose a brand that has a reputable company doing the service/warranty work in your area.

 

[bdhsfz6]

Although I have a few generators, I MUCH prefer to power my whole house generator with my diesel tractor.

I always have it ready to go and if you want, you can park your pto generator near the house in a little house, just like you would have a stationary generator.

It's been working for me for many years now, so I have no plans to change.

SR

I do the same, but I can't dedicate a tractor just for generator duty. I have to remove the mower, spreader, etc and connect the genny to the PTO. I did mount it on a trailer, which I just roll up to the tractor instead of having to mount it on the 3pt. Even so, I'm not getting any younger and it gets to be a chore to hook up every time we have an outage.

As a result, I'm looking at a stand alone, electric start diesel model that I can just plug in when needed. An auto transfer switch is a possibility but not really necessary.

 

[Duds13]

I didn't read through all the replies since I read the thread yesterday so I apologize if this has been covered already. When I looked into the popular whole house generators I got disgusted. There are surprises, such as Kohler units have to have the oil checked every 8 hours or they can void your warranty! Generac says the following: "When your generator runs continuously for 24 hours, shutting it down for at least 30 minutes is essential. This downtime allows the unit to rest, oil levels to be checked, and a visual inspection to be conducted. Performing these steps proactively can help catch any potential issues early and maintain the longevity and reliability of your generator."
They can tell if the unit runs for more than the maximum continuous hours so it has to be shut down and restarted before the maximum time interval is reached. Generac's "free" extended warranty requires a "qualified" tech to service it regularly, which, of course, isn't free and increases the total cost of ownership vs doing your own maintenance.

Quality whole house generators that are rated to run continuously are big money, which is hard to justify for emergency power, so we recently bought another portable. As nice as it would be to have a whole house, fully automatic unit, I can't imaging powering everything down and then shutting down the genny to check the oil level every 8 hours for two weeks straight (the longest outage so far). Even having to do that once a day would be annoying. And if we were away from home when the power went out and the generator ran too long, the manufacturer just got an excuse to void the warranty. No thanks.

If you want a warranty, do not assume anything and read ALL the fine print before purchasing any whole house unit. Best to choose a brand that has a reputable company doing the service/warranty work in your area.

It's $200 to have the annual service done on my Generac. To me that is worth the expense knowing it won't void the warranty

 

[DarkBlack]

A 13 kw unit that has to run max output to power the house will eat more fuel than a 26 kw running at half load.

Every generator I have ever seen, has a higher efficiency at 100% load, than at 50% load.
60-80% loading being the sweet spot for gasoline and propane maximum efficiency, and 70-100% for diesel generators.
So I’d have to disagree

 

[grsthegreat]

I didn't read through all the replies since I read the thread yesterday so I apologize if this has been covered already. When I looked into the popular whole house generators I got disgusted. There are surprises, such as Kohler units have to have the oil checked every 8 hours or they can void your warranty! Generac says the following: "When your generator runs continuously for 24 hours, shutting it down for at least 30 minutes is essential. This downtime allows the unit to rest, oil levels to be checked, and a visual inspection to be conducted. Performing these steps proactively can help catch any potential issues early and maintain the longevity and reliability of your generator."
They can tell if the unit runs for more than the maximum continuous hours so it has to be shut down and restarted before the maximum time interval is reached. Generac's "free" extended warranty requires a "qualified" tech to service it regularly, which, of course, isn't free and increases the total cost of ownership vs doing your own maintenance.

Quality whole house generators that are rated to run continuously are big money, which is hard to justify for emergency power, so we recently bought another portable. As nice as it would be to have a whole house, fully automatic unit, I can't imaging powering everything down and then shutting down the genny to check the oil level every 8 hours for two weeks straight (the longest outage so far). Even having to do that once a day would be annoying. And if we were away from home when the power went out and the generator ran too long, the manufacturer just got an excuse to void the warranty. No thanks.

If you want a warranty, do not assume anything and read ALL the fine print before purchasing any whole house unit. Best to choose a brand that has a reputable company doing the service/warranty work in your area.

Im not sure about Kohler, bur where you read that a qualified generac tech has to do the service work. ANYONE can do service work on a generac and not void warranty. But you must keep all receipts for parts and keep records. If an engine fails during warranty, there going to want to see receipts and proof.

Its easier to have proof when its a certified tech receipt, but its not required.

Now, if it WARRANTY work, than yes, it can only be done thru a Generac certified tech.

Now as to checking oil, this is most important when unit is new. The engine valves and rings have not been fully seated and can lose oil. This thing (generac air cooled) only generally hold 1.7 quarts of oil.

If you truly dont want to check anything for extended time period, stick to liquid cooled. And only a liquid cooled that runs at 1,800 rpm.

 

[grsthegreat]

For the cost of these larger units, I,,m surprised, and dis-appointed that these larger units do not have a transfer system that will power up the complete panel. I have a 11K unit that I manually switch into service, and it allows us to carry on our day completely normal. The only thing I would like to add is a light on the incoming side of the normal power feed so I know the utility power is back on, but it isn,t a big deal, cause one of our neighbours calls us when her back-up system shuts off and regular power is restored.

Again, im not sure what your talking about. I power smaller houses with gas appliances and heat on 11kw units with whole house switches. Its the large houses with all electric appliances that are the issue.

On some large homes with 2 electric panels (400 amp service split to 2 x 200 amp panels) i have even done installs where 1 panel is powered and one is not powered. This is when there all electric. I can place the large electric heat circuits in the non powered panel. This is done for clients that didnt want a 48kw generator.

 

[check]

I didn't read through all the replies since I read the thread yesterday so I apologize if this has been covered already. When I looked into the popular whole house generators I got disgusted. There are surprises, such as Kohler units have to have the oil checked every 8 hours or they can void your warranty! Generac says the following: "When your generator runs continuously for 24 hours, shutting it down for at least 30 minutes is essential. This downtime allows the unit to rest, oil levels to be checked, and a visual inspection to be conducted. Performing these steps proactively can help catch any potential issues early and maintain the longevity and reliability of your generator."
They can tell if the unit runs for more than the maximum continuous hours so it has to be shut down and restarted before the maximum time interval is reached. Generac's "free" extended warranty requires a "qualified" tech to service it regularly, which, of course, isn't free and increases the total cost of ownership vs doing your own maintenance.

Quality whole house generators that are rated to run continuously are big money, which is hard to justify for emergency power, so we recently bought another portable. As nice as it would be to have a whole house, fully automatic unit, I can't imaging powering everything down and then shutting down the genny to check the oil level every 8 hours for two weeks straight (the longest outage so far). Even having to do that once a day would be annoying. And if we were away from home when the power went out and the generator ran too long, the manufacturer just got an excuse to void the warranty. No thanks.

If you want a warranty, do not assume anything and read ALL the fine print before purchasing any whole house unit. Best to choose a brand that has a reputable company doing the service/warranty work in your area.

 

[check]

Wow, Cub, I have not heard about that rule of checking the Kohler oil every 8 hours. I have a 2102 Kohler 17 kw air cooled propane generator, and it has been fine for these 12 years. And we do get a fair amount of outages up here, mostly when there’s a storm, and mostly due to trees falling on Hydro lines.

The one big advantage of the Kohler, is it is really quiet compared to all my neighbors’ Generators. Also, I have an automatic transfer switch, and it kicks in as soon as the power goes out. No big 10 second delay or anything like that.

 

[grsthegreat]

The 6 second generac delay is to prevent startup for every minor power glitch. I can adjust this from 2 seconds to 25 minutes.

Not everyone wants immediate start up everytime theres a 1 second brownout. It comes factory set for 6 seconds. Alot of my customers have had me reset these times. Mine is set for 10 seconds due to excessive power glitches of a few seconds.

I used to service kohlers, and i always thought they were as noisy as the Generacs, when compaired KW TO KW. The only quieter air cooled units i ever serviced were the older model, true Onan rv generators. They ran at 1800 rpm and had cast iron engines. When Cummins acquired Onan generators, they did away with them. Todays Onan (cummins) units arnt near as good as the older Onan. But these older Onans wernt outputting 26 kw in an air cooled unit.

 

[Cub 7275]

Im not sure about Kohler, bur where you read that a qualified generac tech has to do the service work. ANYONE can do service work on a generac and not void warranty. But you must keep all receipts for parts and keep records. If an engine fails during warranty, there going to want to see receipts and proof.

Its easier to have proof when its a certified tech receipt, but its not required.

Now, if it WARRANTY work, than yes, it can only be done thru a Generac certified tech.

Now as to checking oil, this is most important when unit is new. The engine valves and rings have not been fully seated and can lose oil. This thing (generac air cooled) only generally hold 1.7 quarts of oil.

If you truly dont want to check anything for extended time period, stick to liquid cooled. And only a liquid cooled that runs at 1,800 rpm.

So Generac is ok with the homeowner adjusting the valves? I thought I read were Generac denied a warranty because of the maintenance not being done by a tech, I stand corrected. Good to know. Does the Generac have to be commissioned by a certified tech or can the homeowner do it?

Wow, Cub, I have not heard about that rule of checking the Kohler oil every 8 hours. I have a 2102 Kohler 17 kw air cooled propane generator, and it has been fine for these 12 years. And we do get a fair amount of outages up here, mostly when there’s a storm, and mostly due to trees falling on Hydro lines.

The one big advantage of the Kohler, is it is really quiet compared to all my neighbors’ Generators. Also, I have an automatic transfer switch, and it kicks in as soon as the power goes out. No big 10 second delay or anything like that.

Glad it worked out for you. Kohler was my first choice, partly for the lower noise and partly for their hydraulic lifters not requiring valve adjustments on their unit I was looking at. Part of my pre-purchase research was looking at the bad reviews to see how manufacturers' handle warranty claims. Once all the silly negative reviews are weeded out one can see a pattern. That Kohler denied a warranty claim because of the 8 hour oil check requirement I immediately thought was BS, but checking the Kohler literature shows it is true. Likewise for the Generac having to be shut down every 24 hours.

I will admit to being naive and thinking all whole house generators with an automatic transfer switches could run for the duration of the outage, no matter how long that was, and would only need servicing once a year (depending on run time, of course). Deeper digging shows that not to be the case and once all the costs associated with the whole house generator, the ancillary equipment needed for a sound installation, the installation costs and ongoing maintenance are factored in they are much less attractive, even for a DIY installation and even when disregarding any warranty concerns.

Hey we all have to do what makes us comfortable, within our means of course. I'd love to have an 1,800 rpm, liquid cooled, super quiet, whole house unit rated to run continuously, but for our needs it isn't justified. Looking at the compromises with the popular whole house units, they just don't have the value for our situation worthy of their total cost vs a portable with a transfer switch. We did upgrade to an inverter portable that runs on natural gas, so no more lugging 5 gallon gas cans. YMMV

 

[BleedingOrange]

Again, im not sure what your talking about. I power smaller houses with gas appliances and heat on 11kw units with whole house switches. Its the large houses with all electric appliances that are the issue.

I live in Ontario Canada, and have never seen or heard of a whole house panel. All the ones I have seen switch about 10-14 circuits. Would you mind providing a link to some whole house switches.

Thanks for the education.

 

[DarkBlack]

In my opinion, requiring a modern internal combustion engine to be shut down, and checked for low oil every 8 hours, in this day and age, is simply unacceptable and demonstrating poor product confidence.

 

[murphy1244]

In my opinion, requiring a modern internal combustion engine to be shut down, and checked for low oil every 8 hours, in this day and age, is simply unacceptable and demonstrating poor product confidence.

More like a CYA

 

[bcs001]

This is a timely thread as I will be in the market for a 20-26KW whole house generator in the near future. I currently manually backfeed my main panel with a 12KW duel fuel Duromax portable from my 350gal propane tank but have to be careful with overloading the generator running 3 refrigerators, double electric ovens, induction cooktop, two AC units and a propane furnace. AC units do not have soft start so they cannot be used. Cooking with 2 induction eyes or one oven can be done but is a heavy load on the generator.

I will do a load estimate before sizing but my main question has to do with power quality. I know my Duromax is very dirty power and not good for sensitive electronics without power conditioning. Do the whole house units from Generac & Kohler have built in pure sine wave power conditioning and is one brand better than another? Large power conditioners are very expensive so probably not a whole house option.

 

[ponytug]

This is a timely thread as I will be in the market for a 20-26KW whole house generator in the near future. I currently manually backfeed my main panel with a 12KW duel fuel Duromax portable from my 350gal propane tank but have to be careful with overloading the generator running 3 refrigerators, double electric ovens, induction cooktop, two AC units and a propane furnace. AC units do not have soft start so they cannot be used. Cooking with 2 induction eyes or one oven can be done but is a heavy load on the generator.

I will do a load estimate before sizing but my main question has to do with power quality. I know my Duromax is very dirty power and not good for sensitive electronics without power conditioning. Do the whole house units from Generac & Kohler have built in pure sine wave power conditioning and is one brand better than another? Large power conditioners are very expensive so probably not a whole house option.

If you need "clean power" I would put those items on an online UPS, unless we are talking about an induction stove. If you are concerned about power quality, my advice is to buy a generator with reasonable specifications.

I think a lot of people lose hair over "power quality" without knowing how good or bad their grid power is, and what their equipment actually needs.

All the best,

Peter

 

[grsthegreat]

So Generac is ok with the homeowner adjusting the valves? I thought I read were Generac denied a warranty because of the maintenance not being done by a tech, I stand corrected. Good to know. Does the Generac have to be commissioned by a certified tech or can the homeowner do it?



Glad it worked out for you. Kohler was my first choice, partly for the lower noise and partly for their hydraulic lifters not requiring valve adjustments on their unit I was looking at. Part of my pre-purchase research was looking at the bad reviews to see how manufacturers' handle warranty claims. Once all the silly negative reviews are weeded out one can see a pattern. That Kohler denied a warranty claim because of the 8 hour oil check requirement I immediately thought was BS, but checking the Kohler literature shows it is true. Likewise for the Generac having to be shut down every 24 hours.

I will admit to being naive and thinking all whole house generators with an automatic transfer switches could run for the duration of the outage, no matter how long that was, and would only need servicing once a year (depending on run time, of course). Deeper digging shows that not to be the case and once all the costs associated with the whole house generator, the ancillary equipment needed for a sound installation, the installation costs and ongoing maintenance are factored in they are much less attractive, even for a DIY installation and even when disregarding any warranty concerns.

Hey we all have to do what makes us comfortable, within our means of course. I'd love to have an 1,800 rpm, liquid cooled, super quiet, whole house unit rated to run continuously, but for our needs it isn't justified. Looking at the compromises with the popular whole house units, they just don't have the value for our situation worthy of their total cost vs a portable with a transfer switch. We did upgrade to an inverter portable that runs on natural gas, so no more lugging 5 gallon gas cans. YMMV

Air cooled units do not need commissioning, only liquid cooled industrial units. Homeowner can do his own valves. Owner can install, start and service their own air cooled units.
But if there done wrong and engine damage occurs, theres no warranty.

I have lots of customers that never shut their units down during long outages. Ive never had one fail on the units i work on due to this though.

Again, im not sure what your talking about. I power smaller houses with gas appliances and heat on 11kw units with whole house switches. Its the large houses with all electric appliances that are the issue.

I live in Ontario Canada, and have never seen or heard of a whole house panel. All the ones I have seen switch about 10-14 circuits. Would you mind providing a link to some whole house switches.

Thanks for the education.

sure can. a whole house switch has been around for many years. they also have versions that are approved for use in Canada. (CSA Approved). for whole house use, you generally need a service rated switch, and it gets installed between the meter and the house panel.

Standby Generator Transfer Switches | Generac

Generac transfer switches make it possible to switch between utility and generator power.

www.generac.com

 

[grsthegreat]

This is a timely thread as I will be in the market for a 20-26KW whole house generator in the near future. I currently manually backfeed my main panel with a 12KW duel fuel Duromax portable from my 350gal propane tank but have to be careful with overloading the generator running 3 refrigerators, double electric ovens, induction cooktop, two AC units and a propane furnace. AC units do not have soft start so they cannot be used. Cooking with 2 induction eyes or one oven can be done but is a heavy load on the generator.

I will do a load estimate before sizing but my main question has to do with power quality. I know my Duromax is very dirty power and not good for sensitive electronics without power conditioning. Do the whole house units from Generac & Kohler have built in pure sine wave power conditioning and is one brand better than another? Large power conditioners are very expensive so probably not a whole house option.

only inverter generators can get pure sine wave. but the Generac whole house units have something like 5% THD. thats clean enough not to mess with much. my 8kw has NEVER caused any issue with my electronic items. Some portables out there are 20% THD (Total Harmonic Distortion - which plays havoc with electronics). my unit doesnt even cause issue with the 4 UPS units i have running. I have no idea what Kohlers THD ratings are.

 

[t1kilo]

This is a timely thread as I will be in the market for a 20-26KW whole house generator in the near future. I currently manually backfeed my main panel with a 12KW duel fuel Duromax portable from my 350gal propane tank but have to be careful with overloading the generator running 3 refrigerators, double electric ovens, induction cooktop, two AC units and a propane furnace. AC units do not have soft start so they cannot be used. Cooking with 2 induction eyes or one oven can be done but is a heavy load on the generator.

I will do a load estimate before sizing but my main question has to do with power quality. I know my Duromax is very dirty power and not good for sensitive electronics without power conditioning. Do the whole house units from Generac & Kohler have built in pure sine wave power conditioning and is one brand better than another? Large power conditioners are very expensive so probably not a whole house option.

If you want clean power get a military surplus generator - preferably an older Fermont unit. Some will do both single and 3 phase, but the load capacity will not be enough for your said needs. I have a mep803, and it is nothing short of incredible. You can stand next to it and have a conversation without having to shout. Also, it’s designed for continuous duty and is really underrated. I could go on, but it’s really not for everyone.