IBC SL 14-115 G3 vs HC 20-125

Uselessinfo

Hi,

I'm looking for some input to understand the pros/cons between IBC SL 14-115 G3 vs IBC HC 20-125 NG boilers. I received two similar quotes for both boilers connected to an indirect water tank for DHW. The quotes for both is within a few hundred dollars. SL 14-115 G3 has limited lifetime warranty and HC 20-125 has a 10 year warranty.

I'd like some help as to which I should choose.

Thank you,
Paul

SuperJ

What's your system setup? If you're micro-zoned (smallest zone has less heat dissipation ability than the minimum fire rate of the boiler) without a decent buffer, the difference in minimum fire is worth considering. Lower minimum fire rates are often more desirable. If you have a buffer tank, or only large zones then the savings may be worth considering.

Uselessinfo

House - two zones with about 1200 square feet per Zone

HC Quote
Two zone valves, high-efficiency circulator pump, air fitting valve, relief valve, backflow preventer, expansion tank

SL Quote
Expansion tank, Auto water feed backflow, condensate piping and pump

Uselessinfo

Of the two IBC boilers

1. Which would have better longevity
2. Which may actually be more efficient with the given house square footage and 40 gallon indirect water tank?

SuperJ

All things being equal go with the SL.

Things to consider:
Any modcon boiler should have the relief valve, expansion tank, and condensation solution so that shouldn't be a factor.

An ECM circ is worth something (but not a huge deal if you only have 2 zones), sounds like the HC quote comes with one, but circ is not spec'd on the SL quote?

The HC comes with a copper heat exchanger, versus stainless for the SL. I'm a lot more comfortable with the idea of a stainless heat exchanger. How is your water? TDS? Did the contractor mention if they would fill with demineralized water?

For a couple hundred bucks the SL seems like a no brainer. Just make sure you are comparing to apples to apples with the rest of your system. I'd rather have a properly designed system with a copper HX, than a crapshoot with the stainless boiler.

kcopp

Both are fine units.
I have installed both.
The SL certainly has a more sophisticated control.
Zoning can be done from the SL alone.
You will need to have a separate exp type relay to do zoning w/ the HC.
Personally I like the HC better......
Simple design. super easy to clean.
Only 4 Moving parts.
I have about 30 in.

Tom_133

kcopp

I know we dont discuss price but, locally I can buy two NTI's for the price of the SL. What makes it worth all that? Not doubting, just find it hard to sell when its that much more

kcopp

Which model NTI? I cant make a comparison/ contrast a model I am not familiar with...

Tom_133

I understand, and because of the price thing lets just ask what makes the SL so expensive? I am curious if I am just getting the shaft on that model. It looks great but the price makes it hard to sell

kcopp

I have never bought any on the NTI boilers.... nor do any of the wholesalers in the seacoast of NH have them. You must get the IBC stuff from TGG in Barre....
They usually bring a live fire truck around every year.
I can get you the reps contact info if you like....

The SL controller is pretty special.
One feature is The moisture management set up... certainly is far ahead of every other set up that I know of on the market.
The fan runs in low speed for several minutes after a cycle and gets any residual moisture out of the heat exchanger. This keeps the HX cleaner and reduces potential problems.
I'm sure the HX is not the same HX that NTI has...

Uselessinfo

Thank you all very much for your invaluable input. The quote for the HC seems more comprehensive and the installer said that he has one in his house and the company has installed close to a thousand of them.

So even though the SL has stainless, limited lifetime warranty and what seems to be an awesome controller I feel like I'm leaning towards the HC. I'm remodeling my basement and if I do upgrade will be coming from a Burnham boiler that is almost 25 years old and a conventional gas hot water heater. I'm looking to take advantage of the Mass Save rebates and having it all done while remodeling.

Uselessinfo

Oh yeah the primary living zone has a Nest thermostat and both zones have baseboard radiators.

Uselessinfo

Interesting, I just found out the owner of the company that provided the SL quote is also the cities building inspector for plumbing and gas....

kcopp

Uselessinfo said:

Interesting, I just found out the owner of the company that provided the SL quote is also the cities building inspector for plumbing and gas....

No conflict of interest there.....

SuperJ

Sounds like the HC would be the safe bet based on a more complete proposal and a lot of experience with the boiler.

KC_Jones

I'm surprised no one has mentioned the sizing of these units.

115k or 125k for 2400 sq ft of living space. Thats 47 btu/sq ft and 52 btu/sq ft.
Even if you factor in efficiency to get to the output, I don't see how either unit is even close to properly sized.

Has either installer talked about doing the heat loss calculations and an emitter survey?

Both are too big.

SuperJ

KC_Jones said:

I'm surprised no one has mentioned the sizing of these units.

115k or 125k for 2400 sq ft of living space. Thats 47 btu/sq ft and 52 btu/sq ft.
Even if you factor in efficiency to get to the output, I don't see how either unit is even close to properly sized.

Has either installer talked about doing the heat loss calculations and an emitter survey?

Both are too big.

He is heating a space and an indirect tank, and both modulate almost as low as IBC offers with decent TDRs. So the max output may be only be anecdotally important.
The min fire rate is probably something to get fussier over than high fire. The SL wins the low fire contest. (6000btu is a big deal at low fire).

You're right about asking for about the heat loss for the home?
Perhaps the SL 10-85 would work with its even lower min fire rate.

KC_Jones

For me as a homeowner the only way that argument for a bigger boiler with low fire rate wins, is if the bigger and smaller boiler have the same price tag down to the penny.

My gut tells me they don't sell 2 different sized boilers in the same product line for the same price....of course I have been wrong before.

Basically why should I pay for something I will never need....ever.

SuperJ said:

He is heating a space and an indirect tank,

Not sure what you are getting at with this comment? If you are implying the indirect factors into the sizing that would be incorrect.

Uselessinfo

The house was built in 1970. Main living area upstairs was opened up with vaulted ceilings and two skylights. HomeWorks on behalf of Mass Save did a home energy assessment back in Jan and actually recommend the the Bosch ZWB-42-3. I've put a slider in my bedroom and dining room area and when opening the walls there was only a moisture barrier. All the windows have been replaced. Just giving you as much info as I can.

I've had some estimates and these are the boilers that have been estimated...

Bosch ZWB-42-3
IBC SL 14-115 G3
IBC HC 20-125
IBC DC 20-125
Navien NCB-240E

So.....what other info can I provide? I'm in South Eastern MA just north of RI. Sounds like I should have someone else have a look....

Uselessinfo

Btw, when putting the sliders in I did insulate where I could in the outer walls.

SuperJ

KC_Jones said:

For me as a homeowner the only way that argument for a bigger boiler with low fire rate wins, is if the bigger and smaller boiler have the same price tag down to the penny.

My gut tells me they don't sell 2 different sized boilers in the same product line for the same price....of course I have been wrong before.

Basically why should I pay for something I will never need....ever.

SuperJ said:

He is heating a space and an indirect tank,

Not sure what you are getting at with this comment? If you are implying the indirect factors into the sizing that would be incorrect.

I'm not arguing with you.

My point is that both have a lot of turn down, to the point where the high fire rate being on the high side isn't a huge problem (especially since he isn't micro zoned). IBC only make one boiler with a max fire rate of less than 100,000btu/hr. I know we don't size for it, but having a some extra punch for faster setback recovery (or recovery from DHW priority call on cold days) isn't necessarily a bad thing.

Most of the large commercial buildings I work in seem to have double or triple the heating power they actually need but thanks to good turn down ratios and multiple boilers I can still run the building without cycling the boilers (usually less than 5 cycles per day even in shoulder seasons).

The HC min fire rate is about 150% of the SL min fire rate, which means less short cycling and longer runtimes in shoulder seasons if you go with the SL. Even better would be to see if you can use the 10-85 SL.

Maybe give yourself a second opinion with this online heat loss calculator:
http://www.hydronicexplorer.com/Login

SuperJ

Just for reference my house was built in the 1950's in Southern Ontario Canada, it's about 1200sqft with a partially finished basement. My calculated heat loss is only 42000btu/hr, and that even seems a bit high based on the my equipment run-times. So I agree with @KC_Jones 120,000btu for 2400sqft of 1970's construction feels off.

Maybe get another proposal from one of these guys:
https://heatinghelp.com/find-a-contractor/state/RI
https://heatinghelp.com/find-a-contractor/state/MA

Uselessinfo

Thank you! I appreciate everyone's input.

Uselessinfo

I'm still undecided. Attached is a JPG of the SL quote minus pricing. I'm leaning toward the SL but would like to make sure its not missing anything.

SuperJ

The quote doesn't seem have any zoning/pumping. Is that staying as is?
How is your piping setup? Looks like you're removing a cast iron mid efficiency boiler and dropping in a modcon. It's not always a drop in swap, and many times the modcon requires an extra circulator pump and some re-piping.
I'm assuming they are providing a pump/valve for the indirect setup as well.

Can the installer provide some photos of previous installs to help you gauge what you will be getting?

Uselessinfo

So currently the boiler and hot water heater tank are located towards the center of the house. The chimney is in the center of the house. All the quotes, take into account relocating the new equipment 15 feet or so to an outside wall where the boiler will vent directly outside.

I will request some pictures of previous installs similar to the proposed.

Uselessinfo

The installer provided the attached installation picture with multiple zones. Thoughts?

SuperJ

Looks like good workmanship. Ball valves and drains on everything. It's a series primary secondary (the second zone will get water a little cooler than the first because of the sets of close tees in series on the primary loop). Not a big deal if properly accounted for in the design. Probably not relevant for you since your zoning arrangement is pre-existing.
I like the second set of connections for the indirect tank on the left side, helps to keep it tidy.

Uselessinfo

So I'm back to share that the installation is almost a 100% complete. Below is a picture of the installation. Please feel free to comment on the installation.

FYI, my 3rd generation Nest Thermostat which controls Zone 1 is not yet connected. Are there any idiosyncrasies I should know about when using a Nest with this setup

SuperJ

Is that the SL then? I think the IBC controls accept up to 4 zone demand signals, you should be able to connect W1 from the nest to a zone demand signal. The nest will need an R and C connection to work properly. Power stealing (running without a common) is unreliable in my experience.

That boiler must have a built in primary pump? I see two zone pumps and an indirect water heater pump.

Uselessinfo

Yes, this is the SL 14-115. I'm aware the Nest requires a C wire. My question is...does the IBC boiler have the connection for the C wire or does it need to be provided from another source?? I'm not sure about the primary pump...

SuperJ

Looks like it'll work...

http://ibcboiler.com/support/TIPortal/Content/Guides and manuals/Touchscreen_Controller_Manual_English_R5_email.pdf

Uselessinfo

Thank you! I'll check it out.

HVACguyinME

Yes, this boiler is piped wrong. No primary/secondary piping. Not good.

SuperJ

It might be ok if the zones are fixed flow and individually exceed the boilers min flow requirements. I think the SL can control up to four zones.

DaringD

Our experience with the SL has been TERRIBLE. Faulty processor somehow meant that at low BTUs the system was pumping Carbon Monoxide into our home - fire department called twice over a few months - while the installer (with instructions from IBC) extended our exhaust (to prevent recirculation), and then provided a battery back up (maybe it was a power issue) and then detuned the system so it wouldn't drop below 40BTU (so much for high efficiency) - eventually IBC admitted it was a manufacturing defect in the processor and the regional sales guy came and swapped it out. We spent thousands trying to fix the issue and turns out to be something only the manufacturer could fix. Now two years in and the stainless steel HX needed replaced - appears even though our system was purged - the residue from an old cast iron boiler caused the issues - but NOT considered a warranty issue. So this year we will spend another 3K+ on the system. Feels like we bought a BMW - looks pretty - but needs to be maintained regularly at steep prices. Unreliable - middle of the night -25C and my wife and kids were outside waiting for the fire department twice. In my mind - DANGEROUS and UNRELIABLE. I've been told that since IBC was bought by Rheem - good luck trying to get any warranty solutions.