Lochinvar vs Navien High Efficiency Boilers

flyingmeatball

Hello,

I'm trying to compare two boilers and having a hard time doing so. I know not to discuss price, but I don't think anyone will be surprised that the Lochinvar I'm looking at below is significantly more expensive than the Navien.

Design is for ~110k MBTU/h + DHW for 2 adults (standard use - laundry, standard shower, etc)

Below are the key stats that I (as a civilian shopper) care about (apart from price).

Manufacturer Navien / Lochinvar
Model NHB-150 / WHN156
AFUE 95% / 95%
MBTU/h 150 / 125
Turn-down ratio 15:1 / 10:1
Outdoor Reset Included / Included
Matching Indirect HW Tank None / Squire SIT050 52 Gal

Is there something critical I haven't noticed that is different between these models? All of the literature I've been able to find on the Navien claims that it is designed for easy install. Both of them will have an indirect water heater tank attached. I can tell that the Lochinvar seems to have a better reputation, but from the outputs alone I'm having trouble differentiating them.

Thanks!

DZoro

Both are good units.
***When set up properly, combustion analysis must be performed***
Which does your contractor prefer?
Make sure your contractor leaves a print out of the combustion numbers with the boiler instructions.
I have installed and still install both, my personal preference is the Lochinvar.
D

Zman

The difference is in the quality.
The new Hyundai looks much like a Toyota, the specs are similar, why does the Toyota cost more?

Brewbeer

What are you heating, and has a heat loss been performed? 150K BTUs is a lot of heat for most average homes. What are the radiators, and are they large enough to take advantage of condensing technology?

NY_Rob

I don't think you'll find many people who have regretted purchasing a Lochinvar mod-con.

A good many of the problems homeowners have with them is due to incorrect installation by the "professional" who didn't refer to the manual when initially installing the piping, or pumps, or they left out a sensor, or never dialed in the many software options in the boiler control panel because it was easier to leave everything set at factory default.

flyingmeatball

@Brewbeer Heating is for a home with a heating load of 110K, left 30k for DHW. It has a Unico heating coil, which needs 140F water into it, and two radiant floor zones. The plumbing layout I'm looking to run is here:

plumbing layout

@NY_Rob I'm not regretting the specs or the quality, just the price to @zman 's example above with cars, I'm trying to get at how much is "marketing" vs actual quality difference. Today, both Hyundai and Toyota are very safe cars, people buy cars to project an image. I don't need to pay up for image in a boiler, if that makes sense.

Tinman

It's not Image. Lochinvar is a world class company that is putting out great products with great support. I have the choice of installing any boiler brand I choose and my go-to mod con is some variation of Lochinvar's Firetube boilers 9 times out of 10. Nobody's control is even close as far as ease of navigation and depth of settings. The choice is an easy one for me.

It's obviously just an opinion but I'll take it one step further. The only 2 mod cons that I'd happily install in my own home are Lochinvar and/or Viessmann. And Viessmann, from what I'm seeing, is making a strong push to be competitive in North America.

DZoro

Take a look inside each unit. There you will find a big difference.
The Loch is pretty simple, look into the Navien and you will find the Hyundai and Toyota jammed inside.
Hence my preference with Lochinvar. Nice stainless down fire easy to service, clean and access parts. Simple burner, board, gas valve, sometimes simple is better KISS theory is a good thing
IMO
D

NY_Rob

Consider that if you take care of the boiler... it could last 15yrs or so. Now spread the price difference between the Navien and Lochinvar out over 15 yrs... what are you talking $150/yr more to own the Lochinvar?
15 yrs is a long time to have buyers remorse over such a small amount.

Robert O'Brien

Unless you're planning on doing the installation yourself, what you're really buying is the contractor. I personally would lean towards Lochinvar but would much prefer a great Navien install over a hacked in Loch.

flyingmeatball

@NY_Rob True - but to my civilian eye, with the price differential I'm seeing between the two units I could invest the difference at 5% and more than earn back the boiler over the same 15 year timeframe.

Put differently, we could have a boiler and my wife could have a custom walk-in closet, or we could have a boiler. I'll let you guess which is more popular.

Everyone here seems to be much more in favor of the Lochinvar, so point duly noted, but its just a difficult comparison to make if you're not seeing the actual difference day in and day out like many of you are.

delta T

I also strongly lean towards Lochinvar, I have been to their factory training, and talked with their tech support many times, installed dozens of their boilers, and I couldn't be happier.

I will reiterate here that which boiler you choose (both are good products after all) doesn't matter nearly as much as the installation. An improper installation will be much more expensive in the long run.

Brewbeer

@flyingmeatball don't purchase a boiler larger than your heatloss for hot water production.

flyingmeatball

If my heat loss is ~110K, the closest Lochinvar I can find is the KHN155 - link here

Is 121K too big for a 110K load?

SuperJ

Just to be clear is your heatloss 110k, or is 110k the sum of your infloor and Unnico heating capacities?

flyingmeatball

110K is the heat loss from the Manual J. I've done the heat loss 3 different ways, all of them end up between 100 and 110K

Brewbeer

110K at design seems high for a typical residential house. For example, I am heating 2,000 sq.ft. of 1965 era construction split level house with a design load of ~35K (western Mass, 0F design temp). I have a Lochinvar WHN055 that I have set to fire no more than 67%, have no problem keeping the house warm, even at -10F.

Do you heat with natural gas now? If yes, you can do a check on the 110K number you calc'ed by using the gas consumption usage method to estimate heatloss.

flyingmeatball

Lets just take the heat loss as correct - This house has a full back wall of glass, and is close to 4000 sq ft.

Currently the house is ~2400 sq ft, it has been taken down to the foundation and rebuilt.

Ironman

The OUTPUT, not the INPUT of your boiler needs to match the heat loss of your house. Do NOT add anything for heating domestic: the boiler prioritizes that so it does not space heat simultaneously.

If your heat loss calc is accurate, and if the output of a 120k btu boiler comes up slightly less, go with that boiler. Heat loss programs have a 15% + fudge factor built in and your house won't see design temps for more than a few hours at night.

Again, I'd recommend that you take a close look at the HTP UFT 120 fire tube boiler with 10 to 1 turndown. The price point is substantially lower than the Loch.

Steve Thompson (Taco)

Sorry, I have to ask... Where does the "flyingmeatball" name come from??

DanHolohan

I hope this story involves a big dog.

flyingmeatball

Steve Thompson (Taco) said:

Sorry, I have to ask... Where does the "flyingmeatball" name come from??

Steve, Steve, Steve - I believe that qualifies as an "Off Topic" buddy. Nonetheless, even though I'm brand new to the board, the people here have been terrific in going out of their way to help me get my heating setup in order. I'll make a deal with you - there's currently a fundraiser going on posted on the front page of the board (here ) for a board member's wife that has cancer. If you agree to make a donation, I'll tell you the story. You won't be getting value for money in terms of narrative, but it'll be for a good cause.

RomanP

My 2 cents. I install both. Have been doing quite a lot of trouble shooting with Navien recently not my installs. Originally I thought they were good units, after installing about 20 combis by Navien. 3 of them were replaced with the newer generation.

Let me ask you something.... why would you consider boiler and indirect. 30,000 btus left for HW won’t give you much, unless you leave the showering schedule on the wall.

Why not go with Lochinvars new combi unit? Its called Noble. I believe it blew out all the other brands out of the water with their outputs. Their 150000 btu model should suit you well, will save you money, space etc.
Plus, it’s priced very competitively with Navien and it has more features than Navien does.

RomanP

Here’s one

KC_Jones

RomanP said:

Let me ask you something.... why would you consider boiler and indirect. 30,000 btus left for HW won’t give you much, unless you leave the showering schedule on the wall.

huh?
The boiler is sized to the heat loss, you don't add domestic requirements to that.

hot_rod

If you expect a lot of DHW then size to the larger load. A typical gas fired DHW tank is 35,000 or larger. The actual amount of usable DHW depends a lot on incoming temperature. Private wells figure around 50- 55 year around. Milwaukee public water averages 54, dropping into the 30's in winter. phoenix averages around 80.

Plenty of homeowners get by just fine with 40 or 50 gallon 35,000 tank type water heaters. A boiler indirect would give similar performance.

Increase tank size for large dump load, like a soaking tub, expect longer recovery.

A 30,000 boiler/ indirect would be on the small side for DHW, but it really depends on you expectations. some of the small mod cons step up output for DHW loads.

Tinman

It gets tricky when someone is building a large shack with basement, garage, and bathroom(s) radiant, plus 7 good size bathrooms, 2 laundry rooms, and 4 teenagers. And they want to use an indirect. I see that a lot. The DHW demand is greater than the radiant demand.

Rich_49

Sometimes DHW really is the priority .

RomanP

> @KC_Jones said:
> Let me ask you something.... why would you consider boiler and indirect. 30,000 btus left for HW won’t give you much, unless you leave the showering schedule on the wall.
>
>
>
>
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> huh?
> The boiler is sized to the heat loss, you don't add domestic requirements to that.

I kinda missed the fact that it’s for two adults only and on priority 150000 should be enough for 40gal indirect possibly. But I’d still say that installing boiler and indirect is a waste of money for project of this size. Lochinvar Noble combi unit would be my choice

flyingmeatball

The NKC150N has a GPM of 3.6. That doesn't seem like it is enough to support the house I'm building. I don't want to have to worry about starting the dishwasher when someone is in the shower.

Ironman

RomanP said:

> @KC_Jones said:

> Let me ask you something.... why would you consider boiler and indirect. 30,000 btus left for HW won’t give you much, unless you leave the showering schedule on the wall.

>

>

>

>

>

> huh?

> The boiler is sized to the heat loss, you don't add domestic requirements to that.



I kinda missed the fact that it’s for two adults only and on priority 150000 should be enough for 40gal indirect possibly. But I’d still say that installing boiler and indirect is a waste of money for project of this size. Lochinvar Noble combi unit would be my choice

Uh, I'm having trouble following your reasoning: a 150k btu boiler would "possibly" be enough for a 40 gal indirect but you think that's the correct size for a heat loss of 110k that's has 3 zones?

Ironman

Let me inject another thought about combis: maintenance. That FPHX is gonna clog with minerals even faster than a tankless. Depending upon the water condition, it could require multiple cleanings per year. If the HO has to pay a contractor to do this, what's happened to all the $$ he saved by choosing a combi over an indirect?

RomanP

What is your idea for an indirect? Also what is your CW temperature on the coldest day?

NKC150 produces 3.6 at 77 degree rise. You are not running 125-135 degree water in your shower I hope.

Should be good enough to run two showers simultaneously and never run out of hot water. Even if you run dishwasher, that won’t kill the hot water completely. You might experience a slight temp drop.

In my neck of woods incoming CW is around 50 degree range.

If your CW is in 30s then you might have an issue with 150 model. But, personally, I would go for 199 model over installing separate boiler and indirect. Unless you have few more thousands to spend

Ironman

You'd put a 199k btu boiler on a house that has a load of 110k btus? And that's only seen at design temps which is usually less than 1% of the season. At 35*, PROPERLY sized boiler is 2x what the house needs. This is the mean temp for the heating season in most of the country (give or take).

So, your choice of a 199k btu boiler would be 4x the load most of the season. Add to that the fact that the system in question is zoned and your proposed boiler is gonna short cycle itself to death. Then they can get a properly sized boiler and indirect after they "saved" all that money on a combi.

Rich_49

Ironman said:

You'd put a 199k btu boiler on a house that has a load of 110k btus? And that's only seen at design temps which is usually less than 1% of the season. At 35*, PROPERLY sized boiler is 2x what the house needs. This is the mean temp for the heating season in most of the country (give or take).

So, your choice of a 199k btu boiler would be 4x the load most of the season. Add to that the fact that the system in question is zoned and your proposed boiler is gonna short cycle itself to death. Then they can get a properly sized boiler and indirect after they "saved" all that money on a combi.

Easy Bob . Maybe Roman hasn't an idea that an 80K like the UFT and a 30 gallon IDH is just about the same as the COMBI he is talking about , maybe he exists in a bubble where the laws of physics cease to exist and short cycling does not happen or maybe it all just does not matter .

RomanP

first of all, you can throttle down Lochinvar combi to adjust to your heating load. You input all of that information at initial startup. Can’t do that with Navien.

Second of all, he was concerned with not having enough HW with 150 model, which I seriously doubt. Now if you have high hot water demand, you size your system by that.

There’s no rule as to how to size your system. You gotta size both, heating and HW demand and size your boiler to the larger load.

I have zero brand loyalty or setup loyalty. I do have project loyalty. Every job is different and I do install different configurations and brands to satisfy the need. Be it combi, or boiler with indirect, or two boilers with one indirect for redundancy... etc.

For this particular project( heat load and family size) id go with NKC 150 or if HW demand is unreasonably high, with 199 model and throttle down heating side. That would save $2500-3000 on equipment cost alone! Vs boiler + indirect setup. Heck, combi would even have a slight economy advantage, since it doesn’t have standby losses( standby losses on indirect are pretty minimal as well)

The only negative that combi would have is “cold water sandwich effect” but that’s too minimal as well

It’s my personal opinion and my preference to install the system that would do the same thing as boiler+indirect HWH and save a couple of thousands and some room.

Now, can anyone come up with the list of advantages boiler+indirect setup has over combi setup for this particular project?

I’m all ears

Rich, care to post specs for that 30 gal indirect? I’d love to review it and possibly learn a few things? To help me burst my bubble?

Rich_49

Wow , invested quite a bit of time responding to your response to Bob while stating what you responded to was my post . Anyway , good thing you edited , so I could spend a bit more time . You gotta do the math here and not just spout off numbers , Since you seem to have no boiler plate design and have a good knowledge base here ya go , you do the math . We'll use an HTP UFT 80 boiler , HTP SSU30LB indirect . Create capacity and leverage mass . By the way this boiler and indirect combination can probably be done for just a bit more than your combi , which by the way you can turn down to not full fire but , the low end is the low end my friend , and always will be .


The advantages to the following would be less fresh water through the heat exchanger requiring a bit less maintenance .

No 3 way valve switching between space heating and DHW operations , they break , pretty regularly in the grand scheme of things .

No cold water sandwiches , they suck and your customer may not like you after getting shriveled a couple times .

The equipment cost comparison you have given is nonsensical , at least compared to this arrangement .

Don't forget to see the attached indirect webinar in PDF , or look it up online and maybe view for a bit more information than what is in the PDF .

So , an 120,000 BTU @ 85% should give us 102,000 BTUh , agreed ? We're using that one since space heating load could be 110,000 for a short time during the season .
You figure it all out , too much math for me to do for free . Remember , your combi is supplying only 127* water at the rated 77* rise , it will probably give our end user a cold water sandwich ( that's always nice) and requires 150,000 BTUh to do it .

http://www.htproducts.com/literature/lp-81.pdf

http://www.htproducts.com/literature/UFTWallFloor-Brochure.pdf

Welcome to The Wall

RomanP

Rich, That post took a while lol. I was responding to someone else and then you jumped in and I was busy looking at the project, then kids and stuff. So don’t be surprised if you’ll see my post begin at 7 am and finished at midnight. After thoroughly reviewing the information you provided, I do see that systems are close in performance where Combi unit should still perform a tad better under continuous flow condition but that difference shouldn’t be a deal breaker. It would consume more gas in full fire as well. As far as CW sandwich, there’s never really cold water hitting your client. By the time that slug if cold water travels through hot piping, it becomes somewhat bearable. It does require flushing out the heat exchanger once a year or so. Labor-wise, installing a combi does save you time, space and material as your DHW boiler piping is built in.

Basically, it boils down to personal preferences, project needs and budget. I have no preferred design or brand as I said before. You’ll see me doing combi on one project, boiler and indirect on other, all sorts and forms of cascade configurations. A lot of times equipment is dictated by an engineer on file and some of them could be quite stubborn

Thanks for posting those links and I did pick up on couple useful things there.

RomanP

In regards to 3 way valves.... this is the reason Im doubting I’ll sell another Navien again( unless client insists). Went to Navien service call recently. Back and forth with tech support. Long story short, I came back with 3 way valve and in order to replace it, you have to take most of the unit apart! After I did that and put the unit together, opened the valve... their factory connections inside, all the way in the back by that 3 way valve started leaking!!!!!!! I had to take this thing apart again! Applied some blue monster tape and put it all together again only to see it start leaking from another connection. I was ready to punch a hole through that Navien.... my wife and kids were waiting to go to a party and I was practicing my Navien disassembling skills there 3 times. That’s when I said enough is enough.

NY_Rob

FWIW- I have the exact setup Rich described above... the HTP UFT-80W and SSU 30 gal indirect.

In regards to DHW/showers.... as long as you use a reasonable showerhead like the Niagara 1.5GPM head you will get continuous hot water for as long as you want.
One of my daughters takes 30min showers- I sometimes hear the boiler shutting down during her shower because it has met the DHW demand call from the 30gal SSU.

80K BTU's has plenty of capacity to heat 1.5gpm to comfortable shower temps.

RomanP

And then there’s that Grohe tub filler that’s piped with 3/4” copper and flows up to 11-13 gpms

I hear ya, Rob. I’m not against indirect setups in any way. I actually prefer them when there enough budget or system requirements call for it.

One of the better setups, imo, would be two high-efficiency boilers of smaller size, cascaded together to pull a nice size indirect. Here’s your efficiency and redundancy. Not everyone can afford it though