Help comparing my heatloss calc to the builder, and determining options before winter

Gcracker

I have posted here before about how my builder, HVAC installer and the manufactured home company have left me out in the cold. I have spent over a year researching my situation, and educating myself about home heating so that I can make the most informed decision and ultimately, the best resolution from the three above-mentioned parties that agree that somebody dropped the ball.

First, some basic specs:
Home size & insulation
1100sq-ft Ranch
Clg-R38, Wall-R19 (except basement stair walls-R11), Floor-R19
Ent Doors-U.35, Doors-U.45, Wind-U.35
Home location & zone
Maine
Zone 6
Boiler
Bosch 151 Combi on LPG
Heat type
Baseboard fin tube - 34-feet
Single zone loop. No pri/sec
Taco single zone controller and 3-speed pump in addition to Bosch integral 3-speed pump
One BM K42 Kickspace in parallel (not a restriction concern for entire system)
F/L 30 output per foot, in btu/h:
580 @ 180F
320 @ 140F
260 @ 130F
K42 output, in btu/h:
4,278 @ 180F
2,590 @ 140F
2,175 @ 130F

Description of problem:
HEAT:
From October to April, the home cannot recover from even a 3-degree F set-back (69 to 66) in under 5-hours. Boiler short-cycles, running for under 1 minute at a time. A set supply temp of 180F never results in more than minimum fire, and only for a minute or two, even during tests with water temp less than 90F. Fuel usage is high, at ~150 gallons LPG in 30 days. My HVAC installer chose not to install the comfort room sensor/thermostat, or the outdoor reset, so my system is being run in a "dumber" mode.
DHW:
When showering with a DHW set temp (higher than desired) of 120F results in hot-cold-hot cycling 5min into showering. Removal of water saving features of faucets and shower heads is what got us to 5m. Before, we were cycling within under 2m. My research and the HVAC installer agree that this is because our hot water need is less than the minimum flow rate of the combi on the DHW side.

Heat loss calc info:
The modular home manufacturer supplied me with their heat loss calculation figures ("GcrackerHeatLoss.PDF" attached) , and I am hoping for some input here, as I am only barely familiar with this info. I see that they used a DTD of 80F, though I feel that a Maine home in Zone 6 ought to be calculated at 90F at least. Maybe my opinion is wrong there. It also looks like they didn't calculate for any windows or doors in most rooms. Their HLC lists total heat loss at 21,521btu/h. At 180F and 1Gpm, all combined baseboard is capable of a theoretical max output of 19,720btu/h, and the K42 adds 4,278btu/h. I have to have the K42 on at all times to even maintain temperature - without it, temps drop. Even with the K42, heat is hard to maintain, leading me to believe that the manufacturer's heat loss figures are off by a wide margin.

My own amateur heat loss calculation ("Heatloss Calc.PNG" attached, resulting in 31,489btu/h total heat loss) using the Slant Fin app left me with a few questions regarding the manufacturer's calculations. First, the manufacturer's "infiltration" value includes an apparent area calculation multiplied by 0.96 in all rooms except the "Kit/DR/Bath 2" which multiplies by 1.44. How does this equate to the app and the use of much smaller figures? I don't think I will follow a formulaic explanation, but am wondering if my figures likely effectively mirror theirs. As mentioned above, they don't seem to have bothered to calculate any windows except in the "Kit/DR/Bath 2" despite having three bedrooms with single 36x52 double-glazed windows, and the LR having two 36x52.

I would be interested to know if there is a heat loss calculator for home-owners that allows changing the design water temp for compatibility with condensing boilers.

My thoughts:
Running 180F negates the condensing feature of the boiler, shedding up to 20% efficiency in the process. If I continue to run 180F water temps - which I hope not to do - my home requires closer to 60-feet of baseboard. If I want to run 140F to allow condensing of flue gasses, I think I need closer to 100-feet (effective). If I were to run 140F with the same amount of baseboard, even with the K42 on all the time, my calculations (320 x 34 = 10,880 + 2,590 = 13,470) put my max theoretical output at 13,470btu/h. That is roughly one-third of my total heat loss according to my own heat loss calculation.

Without the ODR and the intelligent room comfort sensor, I effectively have a brand new 1950's boiler in on/off mode, with some modulation, but unrelated to room and outdoor temps.

I know that some might advise me against addressing my concerns with the responsible parties, but I have to make an earnest effort to go that route at least once, with all the knowledge I have now. Ultimately, I think there are three people pointing fingers away from themselves, and they are all equally responsible. The manufacturer put too little baseboard in and used figures from Pennsylvania in their HLC. The builder chose an HVAC company inexperienced with condensing boilers. The HVAC company didn't bother doing their own HLC, and used the old school of thought when choosing/sizing a boiler: go huge (151k/btu when system is designed for 24k). He also tied the system in with inferior controls unnecessarily, probably because they are used to them. Finally, HVAC installer omitted ODR and intelligent sensors as he is unfamiliar with them and claims they are unnecessary "for small systems" like mine.

Questions:
To effectively utilize a condensing boiler in Maine, what emitters should I be using? Obviously, I can't install 100 to 125 feet of baseboard, so should this system have been paired with high-efficiency radiator panels? Should radiant heat have been used instead?

If conventional wisdom (that I've gathered from my amateur research) says that a condensing boiler running low water temps should be roughly 100% oversized to recover from setback of 8F, then with my total heat loss of 31,489btu/h, shouldn't my boiler be roughly 60,000btu/h to 70,000btu/h? Wouldn't that make it so that when the boiler modulates down to (the apparently common minimum modulation of) 30%, or 18,000btu/h, it has actually modulated below the total heat loss? If there are combi boilers in that output range, wouldn't that also likely have a lower minimum DHW flow rate, and eliminate the hot-cold-hot showers?

I have to be able to describe exactly what remedy I want to correct my situation, and I think the following would be ideal, but highly unlikely that all parties would agree:
Engineer the system to run low water temps (more baseboard, efficient emitters, possibly some radiant)
Replace Bosch 151 combi with a 65k/btu combi
Add more baseboard OR add efficient emitters OR both

Your wisdom and guidance is greatly appreciated. Thank you all for the help you have provided thus far.

Robert O'Brien

1. Add radiation to allow lower water temps
2. Add ODR
3. Stop using thermostat setback.
4. Live with the fact that it's never going to get above the minimum input.

Or

Throw it out, get a properly sized boiler/indirect. The first 3 apply either way.

Zman

I think both of your heat loss calcs are flawed. I would be very surprised if your actual loss is higher than 15-20 btu/ft.

Your limiting factor on heat is the amount of baseboard you have and the the boiler water temp.

I suspect you are not flowing enough water to the baseboards and this is causing under performance due to lower average water temps. Monitoring the supply/return temps would verify. Primary/secondary with correctly sized system pump would eliminate this problem.

I think that your deep setbacks are likely costing you efficiency as is the boiler short cycling. If you buy into the idea of deep setbacks and larger boiler sizing (I don't) you will need more radiators to help you waste the extra energy.

Brewbeer

I did a heat loss on my 2,000 sq.ft. of heated space split ranch. I used a spreadsheet, the slant fin app, and calculated based on gas consumption and heating degree days. The results indicated that the spreadsheet heat loss was about 5-10% higher than the gas consumption heat loss, and the slant fin heat loss was about 50% higher than gas consumption.

My heat loss down here in western Mass (70F DTD) is about 32K BTU/hr. I designed a baseboard system that would heat on a design day using 130 degree water, and ended up installing 95 feet of high-output baseboard (330 BTU/hr@130F) and 32 feet of lower-output baseboard (230 BTU/hr@130F) for a total of 127 feet of baseboard.

Looking at the house manufacturer heat loss calc, it looks pretty good, but the infiltration factor is probably MUCH larger than actual/needs to be. 20K BTU for mid Maine and your new, modest, well insulated ranch seems like it should be more than enough even at a -20F design.

I'll echo the others recommendation to install more radiation where you have the wall space, and where you don't install baseboards that have a higher output than the ones you are using. I used Sterling Heat Trim Plus for most of my needs, and the Heat Trim line for my lower loss bedrooms.

Take a look at my system design thread (linked in my signature) for the heat loss spreadsheet. if you would like, send me a PM and I'll send it to you to play with if you would like. It allows you to vary the design temp and baseboard output , so it would give you something to play around with if you wanted.

Gcracker

Is 3-degrees (69F to 66F) considered a "deep" setback? By December, we had done away with the setbacks anyway, and told the thermostat to HOLD at 69. Still, there were days that my indoor/outdoor weather station showed our indoor min/max at 58/69 without any setback.

As for my (likely) flawed heat loss calculation, I don't really know how to get it just right with so many industry terms that I have to guess about.

Regarding the flow rate, there are two pumps, both 3-speed units with relatively high flow. I have the specs detailed in one of my other threads, but IIRC, they were moving water very fast with little benefit. Again, regardless of their settings, the result is a cold house that fast-cycles.

If I read the replies correctly, I am hearing that:

• The manufacturer heat loss calc is sound and, if anything, errs on the side of more heat loss than is likely
  
• The problem lies with the pairing of the boiler (condensing) and the baseboard spec'd at 180F, and not enough baseboard
  

Does that sound right? I think this still leaves the problem that a heat loss calc that assumes 180F supply temps paired with a system meant to run 140F isn't going to emit enough energy. Also, apparently no matter what temperature I run the water, this boiler will fast-cycle as there isn't enough water volume, radiation, and on a lesser level, flow.

Do I have that right?

Ironman

Don't use setback with a modulating boiler. It's counter productive to the boiler's logic and will actually use more fuel.

As mentioned, look at high output BB like Smith's Heating Edge or possibly installing some panel rads.

neilc

is anyone else worried that the boiler is on and off so much,
heat isn't leaving the basement /boiler,
op, are the radiators / emitters too hot to touch? ie 180*?
pictures of the boiler, circ(s), and how they relate, and piping leaving the boiler??

Gcracker

neilc said:

is anyone else worried that the boiler is on and off so much,
heat isn't leaving the basement /boiler,
op, are the radiators / emitters too hot to touch? ie 180*?
pictures of the boiler, circ(s), and how they relate, and piping leaving the boiler??

See my previous post here to see pics, charts of my pump specs, my anecdotal description of supply/return temps, and emitter temps.

IIRC, the plumbing is wrong within 8" of the boiler, with the spacing of the boiler supply/return lines being greater than 4 x pipe diameter, as seen in my pics.

neilc

I commented in that thread,
poor flow around the house,
redo that diagram with rad temps, and the temps as you leave and return to the boiler, and post that,

GBart

Honestly this gave me a headache especially the multi colored heat load comparison chart, not much of it is in English but it appears that the home is seriously short on baseboard but it could be the way I'm interpreting the info.

Brewbeer

Yes, my recollection was that you are very seriously short of baseboard. The single loop of 3/4 could also be an issue. was a split loop re-configuration suggested?

Ironman

If the toe kick heater is piped in series, then your flow is restricted to 1.5 gpm which = 15k btus.

GBart

Ironman said:

If the toe kick heater is piped in series, then your flow is restricted to 1.5 gpm which = 15k btus.

BINGO, that could be the entire problem , wow

GBart

I also that in some respects a strict manual J is for the birds, you start adding every layer to your R factor which lowers you btu/hr loss or gain which can give you a number that is not realistic.

GBart

You stated--- Fuel usage is high, at ~150 gallons LPG in 30 days, is this during peak cold?? do we have a leak?, that's @ 5GPD which is extremely excessive.

Jamie Hall

Is it me, or is something fundamentally wrong with the math? If I read that boiler's specifications correctly, it has a minimum net BTU output (lowest fire) on the order of 30,000 BTUh. To dump even that minimum amount of heat into the system at a normal delta T, we are looking at 3 gpm. At maximum fire we'd need more like 10 gpm. And that assumes that there is enough baseboard in there to soak up that much heat -- which there isn't.

So... seems to me that we don't have enough baseboard. We don't have enough flow. We have a boiler which is bigger than it needs to be. We have a problem...

Solid_Fuel_Man

This is the typical throw in some cheap baseboard, set whatever boiler to 180 "because that's what BB needs" and get a huge honken boiler, make it a combi and we dont need no water heater. Unfortunately this happens all too often.

Smallest boiler with 10:1 turndown (going to be a 60-70,000 btu)

Indirect water heater

Radiation sized to the heatloss at 120F water temp

EBEBRATT-Ed

@Robert O'Brien has the correct answer. It's never going to work "right" but may be ok. You have posted on this before. Most everyone has told you to add baseboard

Your 31k heat loss is probably right. You need more baseboard, panel radiators etc. How much? Depends on how much you want to spend. If it was me I would put in as much as possible it will lower your water temp (somewhat) help with short cycling (but not cure it) but will heat your home. Not doing it will shorten the boilers life. If you replace the boiler you still need to add baseboard to make it heat properly. It's not magic but it is messed up. You should be able to get the contractor(s) to pick up at least some of the cost

GBart

The boiler's range is 151,000 to 36,000 input, the lowest output might be 34,200.

The Greenstar might be a better fit with an indirect, the 79 maybe?

Gcracker

I appreciate everyone looking at my threads and offering help. I have some replies and thoughts and questions:

• The kick space heater is not in series. Main loop does not pas through it.
  
• Many suggest what I should do to fix this, but my home heating system was supposed to have been done properly in the first place. I'm not paying to fix something that others are responsible for doing right when they were paid to do it. Not yet anyway.
  
• Is the consensus here that the original heat loss calc is good, or that I have ground to stand on with the manufacturer of the home that did it, and installed the baseboard? I want to tell them it is wrong, and they didn't add enough baseboard.
  
• HVAC installer is telling me that they just "put in what the manufacturer says to put in. Manufacturer tells me the baseboard was chosen to spec, per the HVAC recommendation. Someone isn't being honest, and I have a cold house that costs over $500/month to "heat."
  
• The reason I am here asking for help is to find out what to ask these two parties to do to fix this problem. I am asking for your opinion of what is the best fix, but also, as you are in the industry, you know what is likely to be agreeable to the manufacturer and the HVAC installer. Keep in mind that the HVAC installer tells me that the ODR and other parts that typically ship with the 151 Combi aren't necessary, and either doesn't have them, or refuses to give them back.
  
• Does anyone think my manufacturer or HVAC installer is going to help me? I can mention adding radiation, and re-doing The heat loss calc at 120F, but my experience thus far has been that they pass the buck or tell me "A is false because B is true. No, B is false because A is true. What? I told you A and B were both true and both false? I'll have to see it in the winter. It's too warm to do anything about it right now."
  
• I still have the issue with the hot-cold-hot showering.
  

It seems to me that I should be asking why a heat loss calc was done assuming 180F, and a boiler meant to run 120-140F was chosen. Also, why not enough baseboard was installed, and why it isn't a split zone. Even better, I think this is my list of problems - tell me if you agree that this is all stuff that should be addressed by the contractor(s) and manufacturer:

• Not enough baseboard, for 180F or proper Condensing temps
  
• Too low output from cheap baseboard
  
• Single loop, should be split
  
• A kickspace heater is being used as an integral part of the system
  
• Pri/Sec at the boiler too far apart
  
• No ODR
  
• No intelligent thermostat
  
• Taco 1-zone controller and secondary pump installed for no reason
  
• Heat loss calc came up short
  
• Heat loss uses 80 DTD, Maine (Zone 6) should have 90 or higher
  
• Boiler is too large for heat AND for DHW
  
• Flow was not carefully chosen, just set/forget
  

At the end of the day, it comes down to this: I bought this home in a hurry as I needed a home to live close to my son while going through a divorce. It was not the home I wanted, but the fact that it was "tight" and had a brand new hyper-efficient heating system made me jump. I am upside down right now, and I accept that I will be living lean for a while. I work in IT, and used to be an automotive technician. I get computers, and almost any technology, and I get the basics of plumbing and heating. I have tried all that I can comprehend to fiddle with this system and get it right. It seems to boil down to a serious lack of proper supplies. Too little radiation and water volume, and too much boiler. I just don't have the money to be throwing out the boiler vent, and I have no money for more baseboard or a overhaul of the heating system. I hope to appeal to two parties that should have done the job right, in hopes that they will realize, "Yeah, you bought a brand new home and a brand new heating system designed by the pros; you shouldn't be paying more for heat than when you owned a 100+year-old 3-story 3,000sq-ft with cast iron rads. This thing should be making you smile and saving you money. Instead it's making you shiver and costing an arm and a leg. Let us both discuss the best fix for you and we'll make sure you don't have to go through another cold winter broke." I also realize they are more likely to say, "You can't make me!" but I can be persuasive, and I don't intend to go another year in this home without trying everything I can to get them to do what is right. When I was a landscaper in my early twenties, we had a motto: "Leave the place looking better than when you got there, no matter what." We didn't lean on the houses with our muddy hands, or drag stumps across pavement or gouge up the lawn. If we were sweeping sand, we paid to wash your windows on the house after, and we had vouchers for a car wash if that got dusty too. We took pride in our work, and everyone was happy to pay us more because of that.

This whole situation has me up all night, stressed about when I finally go to these two and ask them to do it right. My hope is that if I point out enough obvious errors and oversights, they will pick a few important ones and fix them. If not, I have relatives that may be able to help me pay for it my self, but I am a principled individual. People shouldn't do this crap to one another. I am more likely to go to court over this than I am to borrow money to fix it myself. I reallllly hope it doesn't get there, because the installer has my hardware in a box somewhere, and the manufacturer and the installer both got paid and didn't do what they got paid to do.

Do I live in a fairy tale land? I hope not...

Once again, thank you all for your thoughts and suggestions. I know I type a lot. I know I didn't include links to my other posts that may have saved you all time in guessing here. I'm sorry that this isn't just a simple, "Where's the on/off button on my boiler?"

Gcracker

Oh, and I will spin up the system tonight from cold and record temps through out. I'll also take a video to show how fast the boiler shuts down. My circuit temps will be below 70F, so it should take a while to get to 180, but it won't. (I always suspected the boiler may be pulling hot water back in from the pri/sec, but I don't get fluid dynamics one bit.)

SuperJ

Zman said:

I suspect you are not flowing enough water to the baseboards and this is causing under performance due to lower average water temps. Monitoring the supply/return temps would verify. Primary/secondary with correctly sized system pump would eliminate this problem.

What Zman said.

Paul Pollets

It's not uncommon for hydronic systems to be installed poorly or incorrectly. A system using a condensing boiler should have a radiator design based on 140 degree design temps. Sounds like you need 20-30ft more baseboard to make this work efficiently. The radiator mains need to be sized correctly for proper flow. If the baseboard is installed in series, the pipe sizing is critical or the radiators furthest downstream won't heat properly. If the radiators are piped in parallel, the main should be 1" with baseboard takeoffs at 3/4". The proper flowrates for pipe sizes are found in Dan's books or in the Library.

Jamie Hall

I think in terms of what the problems are we are pretty much in agreement: nowhere near enough radiation -- baseboard; a boiler which is bigger than it needs to be; and piping which is less than optimal.

That said...

in your initial post you noted that this was a manufactured home. Therefore, the real question -- before anyone can say anything useful about who, if anyone, goofed, is this: exactly what was included in the manufactured home package, and what were the specifications? "Manufactured home" is a rather elastic term, and could mean anything from a home that came on two trailers and was placed on a foundation, all wired and plumbed and set to go, to a home which came as a glorified Lego kit, requiring a builder to figure out how to assemble it and subcontractors to do the plumbing and heating and wiring -- to the manufacturer's specifications, or to someone else's specifications.

Until we know those details, we can't possibly suggest to whom you should talk -- or even if it is worth the bother to talk.

GBart

Has the manufacturer been responsive? Is this a deal where the home was manufactured but a contractor put the system or boiler in after?

Honestly if the home manufacturer put that boiler in they are not thinking, it costs more.

If they haven't been responsive call your state's attorney generals office and/or office of consumer protection and possibly the BBB, you'll need documentation and a timeline and file a complaint. You could also try calling Bosch because HVAC manufacturers do not like contractors that could give their product a bad name.

GBart

This is the link to the Maine Consumer Protection. You bought a new home, it should be fully functional, that's what you paid for.

https://www.maine.gov/ag/consumer/index.shtml

and here's a list of contractors they have sued

Home Contractors the State Has Sued
In the recent past the State has successfully sued the following home contractors for poor workmanship or failure to complete jobs. The files below require the free Adobe Reader. :

State of Maine v. Daniel B. Tucci, a/k/a Dan the Handyman, and TPDF, LLC : Judgement (PDF)
State of Maine v. Daniel B. Tucci, a/k/a Dan the Handyman, and TPDF, LLC : Complaint (Word)
In re: Thomas J. Hutchinson Contractor, Inc. and Thomas J. Hutchinson: Assurance of Discontinuance (Word)
State of Maine v. Joel David Poirier: Complaint (Word)
State of Maine v. Joel D. Poirier and Poirier Construction Company, Inc.: Judgement by Default (PDF)
State of Maine v. Maine Coast Log Homes, Timber Pine Construction, and Mark A. Holmes: Order Granting Judgement (PDF)
State of Maine v. Maine Coast Log Homes, Timber Pine Construction, and Mark A. Holmes: Complaint (PDF)
State of Maine v. CBS Enterprises (PDF) (Kimberly Mark Smith and David J. Blais),
Default Judgement in CBS Enterprises (PDF),
State of Maine v. Frederic Weinschenk (PDF) d/b/a Ric Weinschenk Builders, Inc.,
State of Maine v. Stephen Lunt (PDF) d/b/a Lakeview Builders, Inc.,
State of Maine v. Albert H. Giandrea (PDF) d/b/a AG's Home Quality Improvements, Inc.,
State of Maine v. Al Verdone (PDF),
State of Maine v. Mikal W. Tuttle (PDF), d/b/a MT Construction, DMI Industries, Inc., and MT Construction, Inc.
State of Maine v. Jeffrey C. Scott, d/b/a Molunkus Stream Construction (PDF)

GBart

This is more info
https://www.maine.gov/ag/consumer/law_guide_article.shtml?id=27936

https://www.maine.gov/ag/consumer/law_guide_article.shtml?id=27938

What you may have to do is get Bosch involved, they should be able to send in a factory trained authorized dealer to figure the actual issues, do this in league with the state so they are all on the same page, find out in advance what charges if any Bosch would levy on you.

I think we're all very sorry for the situation you find yourself in, this is not what HVAC is about, most of us take pride in our work and stand behind it. This could be something silly like a piece of a fitting or something is in the pipe blocking flow, it could be more but it the one thing that seems apparent is that the boiler is oversized. Please keep us informed.

Gcracker

Jamie Hall said:

...in your initial post you noted that this was a manufactured home. Therefore, the real question -- before anyone can say anything useful about who, if anyone, goofed, is this: exactly what was included in the manufactured home package, and what were the specifications? "Manufactured home" is a rather elastic term, and could mean anything from a home that came on two trailers and was placed on a foundation, all wired and plumbed and set to go...

This is what my home is. It was in two halves, and drove up from Pennsylvania already wired, plumbed and with baseboard installed. The "builder" builds the foundation, and hires subs and has some of his own. The HVAC installer arrived to the job-site with all baseboard already run by the manufacturer in a single loop to a corner in the basement. His only job was to select and install a boiler, mount a board to the wall, build a manifold, (perhaps he ran the propane lines, perhaps not), and run the thermostat wire to a thermostat of his choosing.

I didn't get around to taking a video last night, but I think I can tonight. My next step, as I see it is to reach out to the HVAC installer and see if he can come out and run a few tests with me. Next, I want to call the manufacturer and describe the situation to their warranty specialist and find out if they have different calculations for the home based on a condensing boiler, and see if we can establish a timeline for resolution.

I will continue to assume/hope they will do the right thing until I have no choice but to accept that I am being actively and maliciously taken advantage of. I will post back soon.

Thank you all for your input and time. This forum, and your help have made it so I fell armed with enough knowledge that I can avoid having smoke blown up... you know.

Thank you again.

Jamie Hall

Tally ho! Your discussion is properly with the manufacturer, who needs to defend their choice of and plumbing of the baseboards.

Not that the boiler isn't overkill, but that's not what's keeping you from being warm enough.

flat_twin

Baseboard was specd for design day in balmy PA? Did the mfg know the house was going to Maine? Was there any up front discussion / options about how much radiation would be needed? The HVAC company didn't question the amount of baseboard? Or did they take a hands off approach since it was already installed? I can see why there are multiple fingers pointing multiple directions.

Ironman

Agreed, the HVAC contractor put in too large of a boiler, but the lack of heat emitters lies with the manufacturer. Also, the HVAC contractor is just a sub of the manufacturer and your recourse lies in addressing the manufacturer. That's who your contract was with, not the sub. Then they can involve the sub as they choose.

GBart

The contractor should've had a heat load to go by. The BOILER IS SERIOUS OVERKILL, IT DOESN'T EVEN RAMP DOWN TO THE REQUIRED BTU'S ON A COLD DAY. LET ME GUESS THE SUPPLY HOUSE HAD A SPECIAL ON 151'S THAT DAY--sarcasm to a degree

If anyone drags their feet you go right to consumer protection. I can tell you what is going to happen, the home manufacturer is going to blame the GC and contractor, the contractor is going to blame the manufacturer and GC and the GC is going to blame the manufacturer and contractor.

You need to find out if the contractor is a factory trained/certified Bosch dealer/contractor, if he is Bosch can and will respond, they may anyway, like I said before. It sounds like you have already asked for help and got nowhere.

GBart

Ask the manufacturer if the home and baseboard were based on your location. I've seen this, on a large scale, at the sub base in Groton, they designed buildings for California or Florida and then built them in Connecticut and it didn't work.

neilc

I still want to know if, with the boiler hot, and cycling on and off,
if the radiator at the far side of the house is too hot to touch, or not.

NYplumber

Just my 2cents after reading the above.

Boiler WAY over sized.
Possibly missing a check valve, pri-sec piping near boiler reversed, shoving warm water back into the boiler and not down stream to the system (short cycling and boiler running at 180f but the system mix temp much lower). Any system sensor installed?
I did not see if this is slab on grade or a vented crawl space however the r30 in the floors leads me to believe this is a vented crawl space raising your heat loss by 10,000btu (calculated off of another home I worked on of similar size).
I would like to see pics of this boiler and its piping.

One of my homes (we live in, not a landlord-tenant home) is a 900sq ft ranch with 500sq ft raw basement (unheated) and 400sq ft conditioned crawl space. All basement and crawl space walls are uninsulated. The rest of the home has insulation from the early 1900s. L shaped house with lots of exposed surface area!
Design day here is between 0f & 5f. heat load on this home was 31,000btu. Mod con runs (clocked meter) at 40,000 on design day. We keep this home at 73f. Anything less and the infiltration will make you chilly.
38ft of cheap Embasy baseboard installed (mistakenly sent from the supplier however we installed it due to a time crunch). Radiant bathroom and kitchen.
Single loop of 3/4 Uponor HePex for the baseboards.
THIS HOUSE HEATS JUST FINE. Bills arent through the roof.

I have repaired issues like the one your having multiple times. It usually comes down to a minor overlooked issue.

Add out door reset (and tune correctly), forget about setbacks, Most likely can live with your current baseboard setup and still condense most of the season (design conditions happen for 3 weeks or so, thats all).
Install a buffer tank to make the boiler last.

Gcracker

I know it's late, but here's a 13min+ video of the boiler fired up for the first time in over 24h, with the thermostat in position. https://photos.app.goo.gl/D6CaptuWaNh4nVFL7
(Apologies in advance for my rambling)

I have the space heating knob set to MAX, and had for about ten minutes. I think this boiler may preheat the heat exchanger despite no call for heat. I checked the service menu, and found that in this configuration, with no ODR, and the knob set to MAX, the "max temp requested by the ODR" is 194F.

You can see the temp starts around 130F, and drops steadily as it should as room-temperature water is pulled into the boiler. The first thing I noticed is that the boiler ran for longer than it usually does when being used for cold weather.

At the 3:30 mark, the boiler had modulated the flame up to more then the lowest modulation and the temperature can be seen climbing quickly.

At 5:54, the loop has reached 195 and the boiler cuts out, but the main pump keeps circulating water. Temp starts to drop, seemingly consistent with adequate flow. Boiler does not immediately cycle back on, despite water temp below set temp and call for heat. Boiler anti-cycle feature is set to auto - no ODR.

At about 7:25 I give a basement loop-tour of the system following the supply out to every baseboard and back to the return.

At 8:08 I incorrectly called the tee for the kick space heater inlet a reducer, because I think it does restrict flow, not to mention the excessive use of 90-degree fittings.

To answer @neilc the copper return at the boiler is too hot to touch, but the pex line at the red-white splice, about 20 feet away can be held onto. I realize now that copper with the same temperature water as pex only 20 feet away will feel MUCH hotter. Ouch. I am taking more videos tonight.

Also, I emailed the builder, who insists on being involved, and he has not responded to me in a week. I'll post back with an update. I'm currently looking at what options are out there for efficient hot water radiators so I am educated if I end up having to do this all myself.

Solid_Fuel_Man

You may have answered this already but is it just a single story house?

neilc

I think I was asking if you reach into the radiator or baseboard at the far end of the house, or end of that heating loop,
is the metals pipe inside that rad or baseboard "too hot to touch" also?
touching the pex would be plastically insulated.
are we sure the loop circulator working?
it could just be hot by the boiler pump.

Gcracker

neilc said:

I think I was asking if you reach into the radiator or baseboard at the far end of the house, or end of that heating loop,
is the metals pipe inside that rad or baseboard "too hot to touch" also?
touching the pex would be plastically insulated.
are we sure the loop circulator working?
it could just be hot by the boiler pump.

It is quite hot. I had originally been underwhelmed with the "hand feel" temp of the PEX on the return, until I grabbed the copper and realized what efficient conductivity is all about!

I believe we have enough flow, if not too much. The boiler being so oversized typically causes short-cycling (as much as the anti-cycle feature will allow), and I am not sure if the flow of the integral and main pumps was done intelligently, but I suspect not. I think part of the problem might be related to that, like in this diagram:


One thing is for sure; I know more about HVAC systems than I ever planned to. Maybe I should start my own company! I already know more than the guy that did my system!

Gcracker

Solid_Fuel_Man said:

You may have answered this already but is it just a single story house?

Yessir