One year NG utilization...

Skyline

It's been a year that the Triangle Tube non-condensing boiler had been replaced with Viessmann 222-F, B2TB condensing boiler. It's time to reflect on/verify the installing company's claim of "You'll save so much money with the condensing boiler". It wasn't just the installing company for Viessmann that emphasized saving. I had four other companies that made the same/similar saving for different brand condensing boilers.

One year NG utilization for TriAngle Tube and Viessmann boilers:



Is there a lot of savings of NG? Yes, around 34% on average, that resulted about the same percentage of CO2 reduction as well. It would be hard not to like these reductions...

Is the saving of 231.87 bucks in a year a lot? You decide... Just keep in mind, that the yearly maintenance cost for the Viessmann probably will be more than that. The yearly maintenance cost for the TriAngle boiler, that lasted 20 years, was around 800 bucks if that. Will the Viessmann last for 20 years? That remains to be seen and I have my doubts about that.

In retrospect, a non-condesing boiler, similar to the TriAngle Tube would have been a better choice for my environment on the long run. If nothing else, the yearly maintenance cost could be a fraction of the condensing boilers. Despite having one quote for non-condensing boiler, for couple of grands less, I picked the condensing boiler. You could say that my decision had been greatly influenced by the condensing boiler installers' "You'll save so much money with the condensing boiler" statement.

On the other hand, I should have researched and compared the different type of boilers, instead of the installers selling "snake-oil". Even it is hard for a layman person, like me, when it comes to boilers. This falls under the category of "live and learn..." and I did by now.

I do like my new boiler that provides even temperature during the heating season, unlimited hot water and does it quietly. Maybe other brands would had provided the same for less, but I liked the 222-F with its 20 gallons hot water tank. There's really no ROI for boilers and the installation cost difference had not been that much between boilers.

This post isn't intended to reflect on the condensing boiler manufacturers. Albeit they state pretty much the same about possible savings, but I dealt with the installation companies. Based on the installation companies experience, they should have stated a more realistic numbers for the possible savings.

Robert_25

How do the degree days for each time period compare?

EBEBRATT-Ed

Maintenance costs could be a killer. Some 15 year old condensing boilers you can't get parts at any price. A blower motor assembly can cost $500 or more. And some suppliers sell the boilers but don't stock the parts

Personally the only time I can see a condensing boiler being a better value is if it has a condensing load

JUGHNE

"Save so much money", that is probably just looking at the max AFUE of each.
Simple CI maybe 85%......Modcon +95%. Sounds like a large savings.
The high Modcon number is IF the return water is low temp to cause condensing.

Do you have CI rads or BB heaters?

The true comparison takes into consideration the heating degree days for each season.

Also, how many sq. feet are you heating and where is this located?

Jamie Hall

At the risk of being a total pest, assuming the degree days are very similar...

Let's suppose that the installation cost was around 10 large (yeah, I know, we don't talk costs, but just this once?). Had you invested that cash in a halfway decent certificate of deposit at 2% (yes, there are some at the interest) you'd have made around $200. So your actual benefit from the investment was a whopping 40 dollars of so...

Hot_water_fan

Be careful when averaging averages, it can trip you up

Tim Potter

"The yearly maintenance cost for the TriAngle boiler, that lasted 20 years, was around 800 bucks if that"

Sorry, are you saying 800.00 total for the 20 year lifespan or 800/yr for 20 years (16,000.00) ?

Tim

kcopp

What model was the Triangle tube?

Skyline

Jamie Hall said:

At the risk of being a total pest, assuming the degree days are very similar...

Let's suppose that the installation cost was around 10 large (yeah, I know, we don't talk costs, but just this once?). Had you invested that cash in a halfway decent certificate of deposit at 2% (yes, there are some at the interest) you'd have made around $200. So your actual benefit from the investment was a whopping 40 dollars of so...

In layman term, yes, the degree days were about the same since my house did not change location. The actual degree days for the periods were:

TriAngle Tube: 6,123.60
Veissmann: 6,074.80

So, if anything, last winter had been warmer, than the previous one. Evidently, layman term is pretty accurate too.

During these periods, the thermostats were set @70F in both zones with the same setback schedules, heating a 1,300sqft house. One zone has CI, while the other is BB radiators. The boiler temperature had been set to condensate, otherwise the NG savings wouldn't be 34%.

I invest in stock, not in certificate of deposits. If I invested 10K in stocks, then I actually lost about 800 bucks by getting the new boiler, but I had no choice. The TriAngle Tube (Phase III?) boiler started to leak some water about two weeks prior to being replaced.

@Tim Potter...

The Triangle Tube boiler's maintenance cost was for the 20 years period, the yearly cost was around 40 bucks.

@JUGHNE...

Simple CI maybe 85%......Modcon +95%. Sounds like a large savings.

As usual, the bottom line is money. In which case, the cost of the NG saving had been 15%. Is 230 bucks savings in a year a lot? For some people, that might be a lot, but not for me.

Comparing two different type of boilers, CI vs. modcon boilers, for the same environment is a valid comparison. There were no other changes to the environment, other than the boiler type. Did we use more DHW, washed more dishes and cloth? I don't believe so, even if there might be a small deviation between the same period.

The point that I was trying to make is that, there's no "large savings" with the modcon boiler for an average house like mine. Especially in the heart of the heating season. Most of the savings comes in the shoulder month to the winter month and the DHW generation on the demand, instead of keeping the DHW hot 24/7.

The other point is that installation companies should know this and present it as such to their customers. If they do know this and don't recommend the right one, then they are dishonest. I am not going to pick on any companies, but based on my anecdotal evidence, four out five companies pushed for modcon boilers, three different brands. One these companies used to recommend Navien boiler 3-4 years ego, but the current quote had been for IBC and did not recommend Navien, even when I asked. One had quoted CI boiler and that company had been right for my given environment and I should had listened.

The whole industry seems to be rigged, individual companies have no choice, but to "go with the flow..."

ChrisJ

Just because the house didn't move doesn't mean there's not huge variations in HDD from season to season.

That being said, of course there's not a huge savings.
Just like there's not much savings when a properly working steam system is converted to hot water and a mod con installed. Yet we constantly see such claims made.

I don't know if these HVAC companies realize they're wrong or not. I suspect most believe what they're selling.

The manufacturers of the equipment on the other hand I think know exactly what's what.
Simple atmospheric cast iron boilers last longer especially with less maintenance and they know that.

To be fair, running the water cooler does have other very real benefits though aside from using less fuel. It's also much easier to make it more comfortable and less noticeable than with higher temperatures.

hot_rod

Really all boilers should have a yearly check, according to their warranty requirements. A cast boiler would be an easier clean and check generally, but still would have a service charge.
Another big plus for mon cons is the modulation function. Properly dialed in it can greatly reduce inefficient boiler cycling and maintain a very comfortable home.
I have seen mod cons run 10 years or more, my own 😙, without a yearly maintenance.  I suppose if you open a mod con after a season or two and it is perfectly clean, maybe a yearly clean and check is not needed?

So much depends on proper sizing, installation, piping, fluid quality, etc

STEVEusaPA

Degree Days-In my area (Philly suburbs) the DDay difference was only 2% less for the second season.

Skyline

hot_rod said:

Really all boilers should have a yearly check, according to their warranty requirements. A cast boiler would be an easier clean and check generally, but still would have a service charge.
Another big plus for mon cons is the modulation function. Properly dialed in it can greatly reduce inefficient boiler cycling and maintain a very comfortable home.
I have seen mod cons run 10 years or more, my own 😙, without a yearly maintenance.  I suppose if you open a mod con after a season or two and it is perfectly clean, maybe a yearly clean and check is not needed?

So much depends on proper sizing, installation, piping, fluid quality, etc

I did have a very comfortable home during the first heating season. I am not certain, if my boiler dialed in correctly, but have some doubt about doing better than it did. Keep in mind, that there had been no changes to heat emitters, the house still uses the same radiators/baseboards. In another word, the "to proper sizing, installation, piping, fluid quality, etc.," had not been addressed.

Based on the initial estimate for maintenance from one company, it will not cheap. It really a costly proposition to have a modcon boiler with its yearly maintenance requirements...

Hot_water_fan

Looks like you saved 27% on CCF, but $/CCF increased by 9%, so the $ saved are a bit lower. That said, if your heat loss is <25k Btu as it looks like yours is, it's hard to save much with a modcon. Important for others to note how inaccurate the Triangle Tube's stated AFUE is when it's oversized.

Skyline

Based on the detailed bills for the periods, the NG cost didn't really increase. While the end result is the same...

The delivery charge on the bills did increase. This percentage of saving is not calculated, they are from the detailed bills from the gas company. The OP just averaged out the NG saving for the year. This number gives me the actual NG savings and related CO2 reduction...

Comparing a 20 year old TriAngle Tube boiler to a brand new modcon isn't fair.

I would be curious to know , how did you come to the 25K BTU loss?

Hot_water_fan

The delivery charge is $/CCF or $/Day or $/month? Basically, I'm interested to know if the all-in $/CCF is the same or not.

Heat loss: 659 CCF * 103,700 Btu/CCF / 6075 HDD = 11,250 Btu/HDD.
On a day with an average temperature of 5 degrees, you'll have 60 HDD using a base temp of 65. A day with an average temp of 5 degrees will probably have a low of 0 degrees. That's probably the design temp for your location, but I don't know.

On that day, you'd use about 11,250*60 ~ 675,000 Btu. At 95% efficiency, about 641k Btu will make it into the home. Divide that by 24 hours, you get 28k Btu/hour.
Some of that will be DHW/cooking/drying and on the coldest day you'll have the highest water temps, so the lowest condensing therefore less of the Btus input will heat the house. So that gets you around 25k Btu.

Hot_water_fan

Comparing a 20 year old TriAngle Tube boiler to a brand new modcon isn't fair.

This is pretty interesting to think about: you don't have a bill from the early 2000s do you?

Skyline

I don't have bills from early 2000s, but do have some from early 2010s. A cursory look look at the bills shows lower NG utilization, but not by much, around 10% less. This might be due to HDD, among other thing. I am just not too interested in drilling down to the details...

Skyline

hot_rod said:

I have seen mod cons run 10 years or more, my own 😙, without a yearly maintenance. ;I suppose if you open a mod con after a season or two and it is perfectly clean, maybe a yearly clean and check is not needed? So much depends on proper sizing, installation, piping, fluid quality, etc

I sort of doubted that the Viessmann 222-F boiler would last that long, until the service tech showed me this picture:



The picture shows a Viesmann heatXchanger: according to tech, this boiler had not been serviced even once in the eleven years. He was called, when the boiler stopped working.

My boiler's heatXchanger looked better after a year, you are probably right, it did not need servicing:

Zman

An HX that ugly probably had very bad combustion. I would guess it was never properly set up.

BigRob

Here is a cleaning before and after at 10 years for a Lochinvar Knight:

I used the abrasive wheel recommended by Lochinvar. The residual scale would not come off. Not sure if I should throw some chemicals at it next time. I think there is another HX below the coil so probably doesn’t matter much.