Costco whole house generator?

[Dave Cav]

I happened to be in Costco yesterday (a very rare experience for me) and saw this whole house 20 KW generator:

https://www.costco.com/.product.100321543.html

We will be building a new house in the near future and it will actually have natural gas, so this looks to be a pretty good deal. I have an 8KW Generac unit which was installed about 5 years ago which runs on propane at my current house, and it seems like it cost almost as much as the 20 KW Costco unit. Any feedback?

Thanks

OK, it looks like I probably should have put this in the electrical subforum.....

 

[mshell56118]

just remember service when needed, who is going to service it, I work for Cummins and it is amazing how many calls we get from people that bought from a big box store and now have a problem with their generator and they have no clue who to call to fix it and then not understand why we cannot file warranty for them

 

[RECox286]

That is the price to pick-up the gen at the store, or at least I should

think that is the deal, with delivery $$ on top of it. Now, you have to

have a separate structure to house it from the wx, or have it sitting

outside in the wx. Then you need at least 1 licensed electrician to do

the hookups... I figure that by the time you are done you could almost

double that amount. If you opt to salvage your existing gen and whatever

equipment it requires, to be hooked up to heater and refrigeration circuits

and perhaps a lighting circuit and as long as it is still in better than "beat to ****"

shape, you will be x number of $$ ahead to put into spray foam insulation for

those cold winters and hot summers. I don't think 20k would be enough to

keep the whole house powered. One of our clients put in a nifty 70k diesel

gen set, in the attached garage no less. What a racket when it "proves"

itself once every week for 20 minutes. Oh, fed by natural gas, of course,

via 1-1/2" pipe from the meter.

Just my 2 sense

Uncle Bob

 

[Dave Cav]

The generator comes with a steel weather enclosure and a built in mounting pad, although I would probably have it installed on a concrete pad. It also includes a 200 amp auto transfer switch. It would be installed in our new home at the time of construction, so installation costs would be included in the cost of the home construction (which will also include full closed cell spray foam insulation). I think as long as we don't try something crazy like running an electric dryer and an electric range, 20 KW should be plenty; we are presently running an 8KW propane generator for selected loads, including our well pump and pressure pump, and it works fine.

 

[Want2race]

I know that model well. I've done a lot of research and almost bought one. Here are the bigger issues that you may or may not have.

Permits! For me it was a $600 permit plus needing a plat with all the trees on my property. Not ideal.

New gas meter- no charge but another permit.. That 20 kw uses a lot of Ng!.
Gas pipe - usually $500-2000 depending on the run. You may be able to run more pressure to the unit and regular there instead of replacing what you may have.
Whole house transfer switch. Basically $1000 to have an electrician pull the permit and rewire the unit right next to the old one.
Wire- this was a shock but 100 ft of service cable isn't cheap. Also don't forget ground rods


At the end of the day the $8900 quote I got to have one installed was sounding appealing. I almost pulled the trigger but saw some good rebates on solar. Since I usually have loss of power for less than 12 hours I'm going with the solar city power wall. Basically its a big *** UPS but has good rebates and cost wise will be under $1000 for me.

If I lived somewhere with serious cold it might be a different story...

 

[Playwme]

You know what us Aussies do when the power goes out?

We go straight to the pub.

 

[onewheat]

Did anyone read the part where he was building a new house and was going to incorporate this in the build?

 

[padroo]

I installed a Kohler 20 k three years ago and it is more than enough to run everything.
I did the work myself and paid a local dealer to inspect my work and do the initial startup.
I did have to upgrade my gas meter and ran 90 foot of underground 1 1/2 plastic gas pipe and I installed it on a frost proof foundation. I bought it online and it was delivered to my door. I have a sump pump and we loose power regulary. When we travel we don't have to worry.

When you get your electrical bid they should install a transfer switch that is built into your main box instead of having two boxes, a main box and a transfer switch. If you want you can install the main box with the transfer switch and install the generator later.

I would recommend finding a dependable local dealer that will service your generator before you buy. My dealer sells both Kohler and Generac.

My 20k generator is only rated at 17k on natural gas. It was a hot summer day when it was started the first time and my A/C was running and the dealer put his amprobe on each leg of the line and each were drawing about 18 amps. Some people think if you buy a generator with a 200 amp transfer switch the generator will put out 200 amps. Mine puts out 75 max.
It seems most generators in the 20k range go with two cylinder lawn mower engines. When you go to the next size you go to a four cylinder car engine and the price tripples.

 

[G-ManBart]

I'm not familiar with that model, but the specs look very similar to the 20KW Generac Guardian we have. I would be a bit concerned with service and support going forward compared to Generac, but maybe some time cross-referencing parts, etc might help ease that concern.

We recently had a wind storm that put us on generator for 105 hours. Our 20KW Generac Guardian handled it perfectly. All I did was shut it down once a day for 10-15 minutes to check the oil and look things over...that's it.

When the power goes out here, we wait 30 seconds, the generator kicks on and we look at each other and say "best money we've ever spent" and go back to life.

 

[matt_i]

While you are building I would have a conversation with an engineer at your utility. I had eyes on a 20kW and learned I'm "capped" at around 12-13kW because of the size of my gas line from the street up to my house. This is due to the potential load from the NG heating.

Cost to upgrade the size of line? Around $500 incrementally when it was put in for the first time when the house was being built. Cost now? Around $5000-6000. The time to sort thru this is now.

 

[reader2580]

Honeywell is just a Generac with the Honeywell name. The price is a few hundred dollars less than a 20KW Generac.

You need to evaluate if you really need a 20KW generator. The costs to wire a 20KW will be more than a smaller unit. For new construction I would consider a subpanel for the circuits that need power in an outage. I can run most of my house on my 10KW generator including central air, but my house is on the smaller side.

 

[bushmechanic]

As much trouble as it is to bring one of those things into service, I wouldn't consider anything less than a branded unit with exceptional local, trained, and thorough support teams.

I mean, the whole point of a generator is to work when nothing else does.

 

[B.S.A. (ret.)]

We've had our Bryant 14Kw unit (rebranded Generac) for well over 10 years and it hasn't skipped a beat. About 5 years ago we had an surprise October blizzard that knocked out our power for 8 days. Had to shut down the unit for an oil change every 50 hours, but she took it in stride and ran continuously for 185 hours. My MIL was on an oxygen generator at the time so the unit was a literal lifesaver. I have a raised ranch with natural gas forced air heat, gas dryer gas stove and gas hot water. This unit runs my central A/C two fridges and a chest freezer. Yeah, I had my local Generac dealer install and plumb the unit and had to upgrade the meter/regulator but the cost was well worth the security. Once warranty was over, I have maintained the unit myself using Mobil 1 oil and changing the plugs twice a year. I'm happy with those results.

 

[Stuart in MN]

It appears you can get the spec sheet for that generator from the Honeywell website here: https://www.honeywellgenerators.com/home-backup-power/generators/20kw Armed with that you can talk to your local utility about the gas consumption requirements.

 

[Ruthless53]

We've got a good friend north of Dallas that does all the electric for Verizon cell towers and has to replace the "old" generators every 8 years because that's Verizon's policy. They are mostly Generac Series 2000 or Kohlers and he buys the ones with under 400 hours of mainly exercise time and resells them. You can get a low time 30-50k name brand generator that normally sells for $16,000-18,000 for $7,000ish with an auto switch. He has the same style 20kw's too but i'm not sure what he sells them for.

I would personally go with a commercial style generator instead of the guardian type. Think of a ford diesel vs a semi truck or big boat diesel. The commercial styles are built to run for a long long time.

I know that is out of the way for you to be reasonable but i see those types of deals all the time on public auction sits/craigslist ect. Just do some research on the seller and buy a slightly used one thats better quality and never worry about it again.

 

[mm08822]

just remember service when needed, who is going to service it, I work for Cummins and it is amazing how many calls we get from people that bought from a big box store and now have a problem with their generator and they have no clue who to call to fix it and then not understand why we cannot file warranty for them

Just go to the mfr website and find authorized service companies. If you can change the oil in your car then you can handle most simple maintenance on a gen.

That is the price to pick-up the gen at the store, or at least I should
think that is the deal, with delivery $$ on top of it.

Delivery is $100 and you need a battery, trim kit and possibly a cold weather kit.

Now, you have to have a separate structure to house it from the wx, or have it sitting
outside in the wx.

They are make to sit in the weather. Get the aluminum housing so you don’t get rust later on.

Then you need at least 1 licensed electrician to do
the hookups... I figure that by the time you are done you could almost
double that amount.
Would require a lot of work to remove and undo the install. Plus 8kw is a little light for inrush loads.
If you opt to salvage your existing gen and whatever
equipment it requires, to be hooked up to heater and refrigeration circuits
and perhaps a lighting circuit and as long as it is still in better than "beat to ****"
shape, you will be x number of $$ ahead to put into spray foam insulation for
those cold winters and hot summers. I don't think 20k would be enough to
keep the whole house powered.

20kw is a lot of power for most houses. If he has ng, then that should be no issue.

One of our clients put in a nifty 70k diesel
gen set, in the attached garage no less.

How much of that 70kw is used? Even unloaded, that is a lot of gas!

What a racket when it "proves"
itself once every week for 20 minutes. Oh, fed by natural gas, of course,
via 1-1/2" pipe from the meter.
Just my 2 sense
Uncle Bob

The generator comes with a steel weather enclosure and a built in mounting pad, although I would probably have it installed on a concrete pad.

The 20 kw comes with a steel housing, the 22 kw generac comes with an aluminum housing. The 22kw actually consumes less ng than the 20 kw.
The composite pad is not so good by itself. I put these on a 6” thick x 3’ x 5’ concrete pad. Since your house will have fresh excavation and soil settling, you need to be careful where you place the gen. Put it on well compacted soil, if not undisturbed soil. Settling makes for plenty of problems. See this a lot with ac units.

It also includes a 200 amp auto transfer switch. It would be installed in our new home at the time of construction, so installation costs would be included in the cost of the home construction (which will also include full closed cell spray foam insulation). I think as long as we don't try something crazy like running an electric dryer and an electric range, 20 KW should be plenty; we are presently running an 8KW propane generator for selected loads, including our well pump and pressure pump, and it works fine.

I assume your range and dryer would be gas. If not, you can place them on load shedding modules.
Also, ac units are typically one of the biggest loads affecting size of unit needed. If you can, put in multiple ac zones so they can each be load shed if needed.

I know that model well. I've done a lot of research and almost bought one. Here are the bigger issues that you may or may not have.
Permits! For me it was a $600 permit plus needing a plat with all the trees on my property. Not ideal.

His new house build will have a property survey, gas and electrical permits already.

New gas meter- no charge but another permit. That 20 kw uses a lot of Ng!.

20 kw uses 308cfh while the 22 kw uses 281 cfh at full load. See if you can get high ng pressure delivered to your meter then regulate down. Someone here had 2 psi which greatly reduces the pipe size as compared to 5-7” water column pressure. Gas co. can answer that quickly.

Gas pipe - usually $500-2000 depending on the run. You may be able to run more pressure to the unit and regular there instead of replacing what you may have.

It’s a new build so I would expect designed in from the beginning.

Whole house transfer switch. Basically $1000 to have an electrician pull the permit and rewire the unit right next to the old one.

Put the transfer switch inside – basement or garage. It is better out of the weather.

Wire- this was a shock but 100 ft of service cable isn't cheap. Also don't forget ground rods

Service will have a ufer or 2 grd rods already.

At the end of the day the $8900 quote I got to have one installed was sounding appealing. I almost pulled the trigger but saw some good rebates on solar. Since I usually have loss of power for less than 12 hours I'm going with the solar city power wall. Basically its a big *** UPS but has good rebates and cost wise will be under $1000 for me.

If I lived somewhere with serious cold it might be a different story...

You know what us Aussies do when the power goes out?
We go straight to the pub.

Ok, pull the plug. Let’s go.

Did anyone read the part where he was building a new house and was going to incorporate this in the build?

If we did that, all threads could be answered in less than 10 replies.

I installed a Kohler 20 k three years ago and it is more than enough to run everything.
I did the work myself and paid a local dealer to inspect my work and do the initial startup.
I did have to upgrade my gas meter and ran 90 foot of underground 1 1/2 plastic gas pipe and I installed it on a frost proof foundation. I bought it online and it was delivered to my door. I have a sump pump and we loose power regulary. When we travel we don't have to worry.
When you get your electrical bid they should install a transfer switch that is built into your main box instead of having two boxes, a main box and a transfer switch. If you want you can install the main box with the transfer switch and install the generator later.
I would recommend finding a dependable local dealer that will service your generator before you buy. My dealer sells both Kohler and Generac.
Easy enough to find on generac website.
Dependable and local may be 2 different things! Some do not like service work/warranty work.

My 20k generator is only rated at 17k on natural gas.
Now they are 18kw.
It was a hot summer day when it was started the first time and my A/C was running and the dealer put his amprobe on each leg of the line and each were drawing about 18 amps. Some people think if you buy a generator with a 200 amp transfer switch the generator will put out 200 amps. Mine puts out 75 max.

My experience finds that most ng homes only draw from 8a to 16a without ac running.

It seems most generators in the 20k range go with two cylinder lawn mower engines. When you go to the next size you go to a four cylinder car engine and the price tripples.

You are into water cooled versions then

I'm not familiar with that model, but the specs look very similar to the 20KW Generac Guardian we have. I would be a bit concerned with service and support going forward compared to Generac, but maybe some time cross-referencing parts, etc might help ease that concern.

It looks very, very similar to generac, but I did notice a few differences. I can’t believe it is on the market looking like twins.

We recently had a wind storm that put us on generator for 105 hours. Our 20KW Generac Guardian handled it perfectly. All I did was shut it down once a day for 10-15 minutes to check the oil and look things over...that's it.

Some people purposely shut theirs down during outages after house gets warm, freezer/fridge cools back down, showers are done, laundry done, cooking done, etc. so they aren’t running it for basically no reason.

When the power goes out here, we wait 30 seconds, the generator kicks on and we look at each other and say "best money we've ever spent" and go back to life.

While you are building I would have a conversation with an engineer at your utility. I had eyes on a 20kW and learned I'm "capped" at around 12-13kW because of the size of my gas line from the street up to my house. This is due to the potential load from the NG heating.

Since it is a new house build, OP should be able to deal with that very easily.

Cost to upgrade the size of line? Around $500 incrementally when it was put in for the first time when the house was being built. Cost now? Around $5000-6000. The time to sort thru this is now.

Honeywell is just a Generac with the Honeywell name. The price is a few hundred dollars less than a 20KW Generac.

You need to evaluate if you really need a 20KW generator. The costs to wire a 20KW will be more than a smaller unit. For new construction I would consider a subpanel for the circuits that need power in an outage. I can run most of my house on my 10KW generator including central air, but my house is on the smaller side.

Using generac made transfer panels limits you from 12-16 ckts -really too small for many people. Putting in a full size subpanel with xfer switch inbetween main panel and sub panel is possible. A whole house transfer switch gives the most flexibility to the user – no need to go back and move circuits..

As much trouble as it is to bring one of those things into service, I wouldn't consider anything less than a branded unit with exceptional local, trained, and thorough support teams. They really aren't that difficult.
Just don't take any shortcuts/go cheap and it starts up like a charm. Especially on the gas line!
I mean, the whole point of a generator is to work when nothing else does.

Simple maintenance goes a long way.

We've had our Bryant 14Kw unit (rebranded Generac) for well over 10 years and it hasn't skipped a beat. About 5 years ago we had an surprise October blizzard that knocked out our power for 8 days. Had to shut down the unit for an oil change every 50 hours, but she took it in stride and ran continuously for 185 hours. My MIL was on an oxygen generator at the time so the unit was a literal lifesaver. I have a raised ranch with natural gas forced air heat, gas dryer gas stove and gas hot water. This unit runs my central A/C two fridges and a chest freezer. Yeah, I had my local Generac dealer install and plumb the unit and had to upgrade the meter/regulator but the cost was well worth the security. Once warranty was over, I have maintained the unit myself using Mobil 1 oil and changing the plugs twice a year. I'm happy with those results.

Generac is now claiming 2 year service intervals on newer models, but I still service at 1 year intervals. I found the oil gets milky from low use even at 1 year.

It appears you can get the spec sheet for that generator from the Honeywell website here: https://www.honeywellgenerators.com/home-backup-power/generators/20kw Armed with that you can talk to your local utility about the gas consumption requirements.

We've got a good friend north of Dallas that does all the electric for Verizon cell towers and has to replace the "old" generators every 8 years because that's Verizon's policy. They are mostly Generac Series 2000 or Kohlers and he buys the ones with under 400 hours of mainly exercise time and resells them. You can get a low time 30-50k name brand generator that normally sells for $16,000-18,000 for $7,000ish with an auto switch.

That’s a lot of power for a home. Big $$ to run even at 1/8 load.

He has the same style 20kw's too but i'm not sure what he sells them for.
I would personally go with a commercial style generator instead of the guardian type. Think of a ford diesel vs a semi truck or big boat diesel. The commercial styles are built to run for a long long time. I guess it depends on your outage frequency, demand and criticality.
I know that is out of the way for you to be reasonable but i see those types of deals all the time on public auction sits/craigslist ect. Just do some research on the seller and buy a slightly used one thats better quality and never worry about it again.

 

[B.S.A. (ret.)]

Thanks to mm08822
This individual knows his stuff. Nice to see a thread that provides information and answers. That's what we are all here for.

 

[wyliesdiesels]

yes he does and sometimes has more time than me to respond to every silly comment....

The one thing i look for in a generator is the RPMs...the costco unit screams at 3600RPMs. I would prefer an 1800RPM unit...

I use to live in an off-grid house that was powered by a battery bank, inverter and a commins/onan 900rpm diesel genset. That thing kicked ***...

 

[padroo]

You don't need a transfer switch and a main panel. I will only guess about other brands but Kohler offers a 200 amp main box with the transfer switch built in. Some people build new houses and install this type of main panel aND later when they can afford it install just the generator.

My natural gas is supplied to my house in a very small gas line, maybe 3/4 in under high pressure and regulated at the Gass meeker to a few ounces. I have a very long run to my generator and 150 foot of either 1 1/4 or 1 1/2 yellow underground plastic gas pipe and it was under $200. My gas meter was on one end of my house and my electrical main was on the other end.

The Kohler website has a calculator where you go down the list and pick what your natural gas usage is and it tells you what size generator you need. Any dealer will do the same even if you just get an estimate from them.

 

[Showkey]

As with many things, GJ can get into overkill mode............huge difference is running the whole house and back up generator to supply power in an emergency (refrig, freeezer, heat, water, lights).

 

[B.S.A. (ret.)]

As with many things, GJ can get into overkill mode............huge difference is running the whole house and back up generator to supply power in an emergency (refrig, freeezer, heat, water, lights).

If this was directed at my post regarding running my whole house, as stated, "my MIL was on an oxygen generator...". She was suffering from lung cancer and emphysema and could not survivewithout A/C or power. When that is the case and you're running a unit capable of handling central air, there is an abundance of available power to keep everything else running.

If my post was not the subject of your comment, please disregard the above.

 

[mm08822]

As with many things, GJ can get into overkill mode............huge difference is running the whole house and back up generator to supply power in an emergency (refrig, freeezer, heat, water, lights).

I believe all replies were based off of OP’s initial details and the order of magnitude system he is contemplating. It is up to the end-user to decide their needs based upon outage history, resulting damage/bad memories, and level of convenience they desire based upon their physical capabilities and technical knowledge. In the end, it is their $$$ and they spend it as they need/want.

A load calculation and rationalization of the loads that he deems important should direct him accordingly to size of system/configuration best for him.

I personally have a 6500w portable generator and roll it out if needed. To each their own.

 

[nh_yota]

You know what us Aussies do when the power goes out?

We go straight to the pub.

Same here.

 

[prostreetamx]

When I wired my house I put all the circuits I would want on a generator in a separate sub panel. I only need a simple breaker interlock to switch from 100a utility power to my 50a portable generator. My system is not automatic and the generator is not connected when not in use so certainly not a system for some but will supply power to my critical circuits when needed. My system is not big enough to run my A/C but will run the FAU's in the gas heat mode. I chose the critical circuits in advance to wiring my house so only the important circuits will be energized. No expensive transfer switch needed in my case. My last house was in an older area and we had frequent power outages every time there was high winds but my new house has not had those issues with all the power companies wires underground.

 

[Showkey]

If this was directed at my post regarding running my whole house,

If my post was not the subject of your comment, please disregard the above.

NOT directed at any other post........except just each person needs a conduct a need analysis and budget.........like mm mentioned. Similar to DVOM purchase discussion in the GJ not every DIY guy needs a $500 Fluke meter.

My neighbor purchased $18k install and we laughed that it ( purchase) will guarantee the power will never go out again.........and I would be more than willing run an extension to my house.

 

[mm08822]

I have recently acquired a Model 4109 Generac Guardian 8kW generator with 60 hours on it. It has the GN-724 engine. I intend to run it on propane. Does anyone else have this model, or perhaps the 6kW or 10kW from around 2001? Any tips specific to this model? From what I understand, it has not been run in about a year. Already picked up oil, oil filter, and spark plugs which will be installed before first run. The air filter for this model is not like the new ones, maybe someone knows of a generic part or I can order one online.

Send me your email in a PM and I can get you pdfs of the manuals.

Provide pics of generator nameplate and engine nameplate with full model number including prefix/suffix and serial number needed for correct versions.

If you have a transfer switch / panel send that info too.

 

[tailshaft56]

We have a portable 5 KW from sears. It was purchased in 2007 do to ice storm. no power for 11 day in an all electric house.

I installed a plug and socket to the fireplace blower for heat. at least we had heat, some lights, fridge and freezer.

Beats the hell out of candle and batt radio. LOL

 

[Dante6889]

"Reading your posts, I remembered. My friends also asked this question, they are in the trailer. Of course, they needed a generator.

They do not understand them, of course, it was necessary to contact me, I would help.

In the end, they bought it themselves. They were lucky, the model is pretty good, but they say they liked the description. I recommend reading here (that's where they finally found it) about them if there are problems with the choice "

 

[LifeLongWNYer]

"Feature creep" is alive and well in the home generator world.

I can remember when a "generator system" meant dragging the generator out of the garage, and running an extension cord from it to the house. Then, generators which powered selected circuits came onto the the scene. Now the rage is "whole house" generators. There are two installation firms which advertise incessantly every time we get a wind or snow storm. They imply that "you ain't ****, unless your generator can power every thing electrical, in your house, all at the same time".

I am not saying a whole house generator is bad, but it isn't a necessity either.



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