Maximum temperature problem with new Viessmann Vitodens 222-F

Paul48

Alex.......The problem with fin-tube, is , it loses about 20% of its rated output at 165 degrees vs. 180 degrees. If you ran close before , you're not going to get there now. You're left with tightening the envelope, or adding radiation.

GW

AZ, that's less good, conventional BB needs hotter temps to make the convention process happen. You're gonna need to do at least one of the following three things:

Get a boiler that will make hotter water
Add more baseboard (BB)
Reduce your heat loss

How many feet of BB do you have in the house?

Paul48

I won't bother defending my 5th grade stupidity , or his. We both know that there was no winner.

icesailor

Personally, I think that the oil boiler was "oversized. But what you describe with the way it operated when it was cold and running, is what is considered normal and proper operations.

There is an obsession with putting boilers that are perfectly matched with a design load. If the new gas boiler is rated at a lower number than the old oil boiler, some might consider it undersized. Especially when you size the heat loss for the rooms, the installed radiation, and how close they are all to each other.
Look at it like this.
In 1886, I bought a i986 240 SL Volvo wagon. It had this famous Volvo 4 cylinder engine, It had a standard 4 speed manual transmission. It was peppy and economical to run, went as fast on the highway as you ever wanted to go. One of my daughters went to U-Mass, Amherst. We drove from Cape Cod to Amherst, Massachusetts. With three adults in the car, it barely went 70 MPH on the flat and on hills, I had to shift into 3rd. The engine just didn't have enough nuts to make it up the hills without getting more power out of the higher engine RPM's. So I drive up the hills on the Mass Turnpike with the engine screaming in 3rd gear at 50 MPH. My 1989 Ford F250 HD with a 351 CI Cleveland engine would stay at 70 MPH for the whole crowded trip. Cold houses and loaded vehicles need NUTS to pack them around.

IMO.

Paul48

Lesson of the day......Beware of nuts driving 1886 Volvos.

Paul48

The lack of horsepower was because one died.

Gordy

Really I'm seeing stabs in the dark here.

What we know is the old boiler was 125k gross input or net output?

We know it's an old Victorian house. With no insulation. Still need a room by room heat loss. How many SF?

We know OP has fin tube base board. What we don't know is how many feet in each room, and how that correlates to the rooms heat loss.

We know he has the v 222. What we don't know is how it's piped. Low loss,header with sensors properly place.? P/S pumps properly sized? Zoned?

We know the house is cold. How cold? What outdoor temps? Is it ever war? What set point is the OP trying to achieve?

With out definitive answer we can not provide solutions. Everything is guessing at this point.

Yes to insulation. Think of it as the gift that never stops giving.
Sealing of cracks weather stripping another gift.

alexzaslavsky

As suggested by Paul48 (I think), here are a couple of pictures of the system (jpeg format, I hope they are visible).

In the plumbing close-up, you will see that one of the circulator pumps has been replaced by a higher-capacity model -- this seems to have helped, on the first floor, but only slightly.

I could try to measure the linear feet of the baseboard, but is it the sense of the community that I should be thinking of replacing the boiler by something that produces at least 185 F of hot water?

Thanks, the depressed AZ

icesailor

That installer did a really nice installation. All the bases were covered except one.

I was told on the first day of my time in the trades.

You can do the nicest job possible. But if you leave a mess behind, people will think you are a slob, a bad mechanic and that you screwed them with bad work. However, if you do a job that doesn't come out the way you want it to, but you leave everything far better than you found it when you came, Marine Corp/Navy (Military) Clean, they think you are a hero and did a wonderful job. I heard that advice my whole long career. If I cleaned a boiler, I vacuumed and swept the floor for many feet around the boiler, wiped the dust and grime off the boiler and piping, and left it looking as new as I could. People were happy.

When you go to the doctor and you need surgery, they run all kinds of tests to see your health. So when they do the surgery, they and you don't have a problem.

Like the doctor and the testing before surgery, the person doing an boiler replacement in an old house, needs to do a comprehensive and accurate heat loss estimate. Which MUST include measuring the output of ALL emitters in each and every room so they can see how the original system was installed and balanced. If you don't, you're taking a shortcut. Shortcuts have big teeth that can bite you in the butt when you least expect it. It can hurt you. You better have some idea what the old system was designed to, and whether the old system worked because it was a gravity system that was designed to 165 degrees, but the high limit was set for 180 so it worked. Because if you go and design and replace a system that connects a 165 degree boiler to that system, you might need a visit to your friendly Proctologist for some personal repair work.

Vitodens 100's and 200's were hard enough with 170 degree water on a close to design day. That new one is even worse. It will bite them in situations like that. Maybe Veissmann will come out with a "patch" to raise up the temperature. If the system is generating a 20 degree Delta T, the last emitters are seeing 145 degree water. How much is the last emitter now delivering, and does it just happen to be in a room that was under radiated from the beginning, and the other rooms were adding their heat to the under radiated room? You can radiate a first flor and not the second, but the second floor will be warm. The first floor might be cooler than expected.

In my worthless opinion, the cheapest and easiest fix for this situation is an small electric water heater, big enough to have a 240 volt, 5,000 watt element in it, and connected to the boiler side of the Hydraulic Separator. It would only run when it was design day cold, and would add an additional 15,000 to 17,000 BTU's to the system. That boiler simply doesn't have enough nuts to make it up to the top of the hill. And if the OAT goes up 20 degrees, and the system handles the load, the system is underpowered. Power coming from the boiler.

jim_94

If you have enough space in the rooms to add baseboard to get it to work at a design temp of 150 degrees on a -10 degree day that is what you should do. Adding insulation would be a definite help and if you do that before adding baseboard you may not have to add as much baseboard (or maybe even any). Change the boiler as a last possible option. The boiler WILL work with baseboard as long as there is enough for design degree day.

This would be the order I suggest:
1. add insulation
2. do a new heatloss calculation with -10 design day and 150 water temp
3. check the amount of current baseboard in regards to the new heatloss
4. add baseboard if necessary(if you have dummy baseboard cover this is not as difficult to do)
5. if you need more baseboard and can't get any in then and only then look at changing the boiler.

*I suggested the -10 and 150 degree temp because that is what we use and have never had a problem. We are located in the Boston area and design day is either 8 or 9 degrees but as we have seen it often goes below that.

Proper insulation can cut a heatloss significantly 25% or more sometimes(especially if you're in an old victorian with minimal to no insulation)

Your installer did a good job on the install and it would be a shame to take out such a nice piece of equipment when there is a good chance it can be saved.

jim_94

Hatteras, have you ever put one of these in with fintube? I'm not trying to be wise or disrespectful, I'm just curious. We have put that exact boiler in with existing fintube radiation(none added since there was enough for the heatloss at -10 and a system design temp of 150) in a house that was insulated and it works perfectly. This is a real life example of it working with fintube. You can say all you want how it will not work but the truth of the matter is that it does. The only difference between this install and the one we put in and this one is we used a buffer tank not a LLH.

Again, he should insulate the house, redo the heatloss calcs and check the baseboard installed against what is needed.

The original poster should not just throw the boiler out and put in a condensing boiler that will go to 190, spend most of it's time above 160 in non condensing mode and basically lose all the benefits of having a condensing boiler. If he wanted to do that he could have put in a 85% gas Buderus and achieve the same results for less money. Although he would have to then get an indirect too.

Obviously the boiler will not work properly on the cold days as the house is currently set up but neither did the previous boiler from what he has stated. The house should be insulated regardless of whether he keeps this boiler or puts a different one in. Insulation is one of the best efficiency upgrades one can do to a house. If the homeowner is in MA he should contact Masssave to see about the incentives for insulation.

Don't throw the boiler out until there is no other option. It will and does work with fintube. Btw the Vitodens 100 that your friend had put in goes to 180 but even that does not sound like it would be enough since the old one didn't keep up either.

Insulation is the key and will make a world of difference.

Tim McElwain

Run more lineal feet of baseboard so the applied temperature of say 160 degrees will satisfy each room heat loss. That will also insure continued condensing of the boiler using a 40 degree Delta "T".

This max temp on Viessmann 200 series is something overlooked a lot of times, keeps coming up all the time.

GW

A minority on heating guys would be able to pull of designing a system that unloads 40*, that keeps all rooms cozy. True or False? Yes, No?

icesailor

@Hatterasguy:

You must work around a lot of a very wealthy customer base. I'll guarantee you that mine was much higher than yours, and hydronic was a tough sell against scorched/frozen air that wouldn't warm an igloo enough to keep an eskimo from freezing to death. Many of us have/(had) a customer base that baseboard was what they could afford. For me, I knew that when they wanted panel radiators and infloor heat, I better figure baseboard too and put that in as an option because that is what they would go for. Once they get the price, they either think you are screwing them, or they see the difference, ask around, and find out why.

You can talk until you are blue in the face, but if they can't afford panel radiators, they won't go that way. You sell what they will buy and can afford.

When they say "Sharpen your pencil", they are saying to work for less and give them more. The "winner" is the one who looses the most on the job.

@Jim:

You figured out what IBR figured out many years ago on how to "fudge" the calculation. Boston being +9 OAT but you design for -10 OAT. That still leaves you with a 15 MPH wind speed. You ADD emitters rather than Subtract emitters.

Most bathrooms in an insulated house need less than 1 1/2'. No one cuts a 3' baseboard in half, we install a full length 3' piece. Or a K42 Toe-Kick. Where low speed is still overheating.

Boston and vicinity is much colder than where I lived, but the IBR factor was way below Boston because of the high consistent winds.

James Day_2

You are not running the system at a 40 degree delta, only the boiler. You are running the house at a 20 degree delta, primary/secondary piping ensures that. What you will get is blended temperatures. Also I believe viessmann is not looking at the water temp in the boiler as much as it is looking for the temperature at the low loss header sensor. I was told that the boiler will maintain the 165 at the low loss header sensor. I install a ton of Vitodens 200's which max out at 167 degrees and have never had any issues with fintube.

James

Gordy

Actually they "strongly suggest" you use their low loss header instead of P/S piping. And I agree with James on system delta verses boiler delta.

Gordy

I will say the manual can be miss leading if not carefully read. But if you read carefully. They do say the emitters need to be designed around the boilers parameters. We mostly keep this in mind except when it comes to American made boilers we have the latitude to use higher than 165 water temps, and shoot the boilers efficiency all to hell. The Germans refuse to allow this to happen to their boiler design. You want efficiency you got it, and by God your going to keep it that way.

jim_94

The baseboard was going out at a flow rate of 3-4 gallons a minute if I remember what the Grundfos Alpha was saying. You separate the flow rates in a primary/secondary piping arrangement. The boiler sees its flow and the baseboard, radiators, radiant floor sees it's own flow rate. They do not see nor care about each others flow. It's very simple. I let the internal boiler pump that comes on this particular model do it's thing and pump the radiation in autoadapt on the Alpha and let it find it's grove. This model always maintains temp based on the outdoor temp so any time a zone calls it pulls off water at the proper temp based on outdoor temp and the heating curve settings.

You've never put one in but all you are doing is bashing it and saying it won't work when it does work. That is your opinion and that is fine as you will obviously never put in a Vitodens 200 series boiler on baseboard since they all have the same default degree limit. We have done Vitodens 200 with fintube, cast iron baseboard, radiators and radiant floor and it has worked in all applications. Only one time did we have to add baseboard to an existing system to work properly on days below 10 degrees. We have done two of the 222f, one on fintube and one on cast iron radiators.

Also when running low temperature we want it to run as long as possible, ideally the circulator would never shut off. I'm not worried about a 40 degree delta t across the baseboard. I'm concerned with the temperature in the house being even in every room. To do this you lower the temp and slow the flow. If I can heat a house with 125 degrees uniformly across the baseboard why would i push it up to 150 or more to achieve a Delta t of 40 or even 20? Delta T is rarely, if ever, matched in a baseboard system. Plus every 3 degree increase in water temp is a 1% increase in fuel. So unless you need to keep the temp up, like you do in a cast iron boiler, why would you?

Now obviously in the case of the original poster he has to speed up the flow so he can get as much as possible out of the existing baseboard. That would most likely not be the case if the house were properly insulated but again that is a guess on my part as we are all looking at this from afar and not in his house.

As for the AFUE of the 100 vs an wgto, in a low temp situation a 100 will be around 95 in a non condensing it would be high 80's and a wgto is 86-87. The issue with only looking at AFUE is you're not looking at system efficiency, you're looking at burner efficiency and also listed AFUE's are done in a lab with perfect supply and return temps, not in the real world. You need to lower water temp to increase system efficiency so you need to use something like a Tekmar TN2 system or a Buderus Logomatic to vary the water temp to match outdoor temp. Of course with a cast iron boiler you're using the boiler as a buffer tank. That is why you can take a 85% boiler with outdoor reset and get it to provide overall system efficiency in the high 80's which is comparable to a condensing boiler that spends most of it's time in a non condensing mode.

The 100 also has a different control package and is an on/off boiler unlike the 200 series. If I remember correctly the big thing about the 100 when introduced was that it could go to 180 for jobs where you couldn't add extra radiation.

I agree that he would be better off with panel radiators. It would be a big improvement over baseboard in any heating system, no argument there. One possible issue could be the windows in old Victorians are usually quite large and sometimes close to the floor.

As for sizing it to the hot water, we don't do that. We size to the heat loss and oversize the indirect with an anti scald valve.

However on this boiler it is sized to the DHW because this is a combi boiler that comes as a package with a 26 gallon indirect all piped in as well as a flat plate heat exchanger. When the tank stops keeping up a solenoid will divert the water through the flat plate to provide approx 3.3 gpm of DHW.

You're not going to agree with me that it will work. To be honest, it really does not matter because you and I are not going to agree. I will keep putting them in and you will keep saying it will never work.

I just do not want to see the poster throw out a amazing boiler right away. Take the time to insulate first, recalculate second and then see what he has to do. Most likely the boiler will end working with insulation and maybe some extra heat emitters. Of course if he has the room and wants to do panel radiators it will work better than baseboard in any system, as I said above.

*also I believe that the max water temp is designed to meet the German codes/laws that govern the maximum water temperature in a heating system to provide maximum efficiency. I think some asked about that in the beginning of the thread.

**also I said earlier that the 200 series all have the same max temp but I think that the larger 200's that might be used in a small commercial setting can also go to 180. I want to say it's the 350k to 500k models.

Harvey Ramer

alexzaslavsky said:

Glad to hear there may still be hope due to pumping issues and thankful the experts are still interested in my troubles.

A couple of folks brought up the "emitters": we have standard forced-water baseboard (pipes with fins), they have not been changed in any way. It's a 3-story Victorian house + semi-subterranean finished basement, so 4 zones total.

Also, regarding comparisons with the previous Weil McLain oil burner (with the same nominal 125K BTU capacity), I do not want to give the impression that the old furnace handled the job easily. During a true cold snap (a couple days with outside temperature of around 0 F), it would be firing nearly all the time and still the living room temperature would drop from 68 K (thermostat setting) to something like 65 K. And the oil consumption was fierce (1500 gallons per year). But the current situation with the Viessmann is much worse, at least as far as comfort is concerned.

I will take some photos of the piping tomorrow and post them. Thanks to everyone, AZ

I feel bad for you and the trouble you are having. But here is another way to look at it; you made a very good investment and as soon as you pay the balance you will have a system better than most people in this country have.

The balance you must pay is this. You have to have someone do a comprehensive heat load calculation on the house. You can hire someone to do this, or take advantage of some free online programs and do it yourself. The heat load calc is going to tell you exactly how much heat you need in each room.

Once you have that math completed, it will be possible to determine what size emitters are required at the water temps your boiler will produce. You may find that some areas of the house have enough emitters while other areas are lacking.

Also you may want to upgrade all the baseboard to something new that will perform exceptionally well at low water temps. If you chose something like this http://www.smithsenvironmental.com/html/he.html
it would cover up the unpainted area behind the current baseboard. This would also take full advantage of the new boiler's condensing capabilities and markedly improve the efficiency.

Panel radiators are also a good option and could be used to supplement the existing baseboard.

If you would like to enhance the beauty of that old Victorian house, look through these gorgeous radiator selections http://www.runtalnorthamerica.com/residential_radiators/pdf/2008Hydronic.pdf

You could also supplement with the classic look... http://www.ocsind.com/cast-iron-radiators.php


At any rate, start with a heat load calculation and don't throw away that boiler just yet.

jim_94

Ice, we design for -10 because it does go down to that temperature. Not often but it does. And I understand that you ADD emitters not take them away as you design for lower temps. I do not consider what I do as far as design day to be "fudging" I consider it to be using the real world as my guide.

*it looks like some people have already some of the things I said in my previous post, so sorry for having to make people read it twice:)

jim_94

Obviously you are the master, I have not been insulting to you but if it makes you feel better to insult me go for it. I was simply pointing out the boiler pump and the system pump work individually of each other. This particular boiler has a BUILT IN boiler pump that will produce the right flow through the heat exchanger and a LLH or buffer tank. It is not like most other mod cons that you install the boiler pump after and size to head loss and gpm. But I'm sure you know that since you know how many btu's I'm getting out of boiler installs that you have never seen and know what i'm getting for efficiencies out of a boiler you have never installed or worked on but have no problem trashing. And you trash me and say I have no idea what I'm doing. I don't need to spout off flow rates and delta t to impress everyone. I guess I am just not as smart as you. Pity.

You don't like the boiler, i get it. I guess it's a good thing i'm really lucky on all the installs we do. All you want to do is quote flow rates and delta t but you don't understand that it is through the boiler not through the baseboard that Viessmann is looking for. All you want to do is say it won't work when it does. Viessmann did not get where it is today by producing things that don't work. The boiler is doing what it is supposed to do, the house needs to be insulated and then the amount of baseboard checked to see if it matches the new heat loss at a max temp of 165. It says right in the manual and probably the brochure what the max temp for the boiler is. If you don't like it call Viessmann and wow them with your knowledge.

My point was that if the WTGO could not keep up at a guess of 180-200 degree boiler temp there is no way a boiler at 165 is going to keep up. Now feel free to start spouting off about the btu's you get 83% or whatever % and how that translates to so much 180-200 degree water vs 90% at 165 degree. If it can't keep up at 180-200 it's not going to keep up at 165. It's simple but feel free to go and school me on the laws of physics. It will make you feel better.

In the meantime I will keep getting lucky on every install I do condensing, non condensing, steam etc. I don't know why I even bother doing heat losses or measure radiators for steam, I'm so lucky I should just guess.

This thread has gotten away from the original point of trying to help the poster and what he can do with what he has. Insulate, new heatloss, check the radiation to see how it measures to the new heatloss and fine tune it from there whether it be more baseboard, panel radiators or whatever he chooses.

icesailor

"" Surprisingly, some of the panel rads get down close to the pricing of the baseboard. The T6 that I referenced are quite a bit more costly, but, at the end of the day, would you rather replace the boiler or the radiation? ""

Surprisingly, I've never seen a 40 YO fin tube baseboard with a hole rotted through it with water leaking out of it.

Unlike some 10 YO panel radiators I've replaced.

Maybe you can find some El Cheapo panel rads. The labor and material to install them makes them a tough sell in many markets. Are you buying and selling them or is the architect/designer or contractor buying them and you're just providing your knowledge to install them?

GW

You two need a time out!

These are all separate topics, and we have done a fine job mashing them all together:

--what is the heat loss
---yesterday, today, and tomorrow, all variables that can (or have, or can be changed) evolve over time

-what temp does the emitter system need (how hot) to keep the house comfortable; this answer does not care how new or old the boiler is.

-How hot can the water get (will it be adequate for the above points) from said boiler (165 has been established, no one arguing that one? I personally have not read any docs on this unit)

-IF the heat loss is matching the full rated capacity of this boiler, how easy/difficult is it to make the numbers work (math doesn't care how smart or dull we all are). If the heat loss is less than the rated capacity of this boiler, then the math changes as to what is possible and impossible (math again). 6.5 gpm with 125,000 BTU is no easy task.

-AFUE, nothing to do with mother nature sucking heat out of the house, that's a different topic, but, I suppose someone could try and make it a topic.

--AFUE that the boiler is actually operating at: another topic that is separate from the OP's main question, yet again, lets confuse everyone and make it the main topic.

-A LLH can not trick math, if your AWT is X, then you boiler must make it happen. A LLH is a bigger version of a p/s; there are no BTU rewards for having a bigger column of water to separate distribution from the boiler. How in the world can you have 20 dT at the system and 40 dT at the boiler; IF you're hunting for top of the range temps?

icesailor

"" If the WTGO could not quite keep up with a combustion efficiency of 82%, there is a POSSIBILITY that the 222 could keep up with an efficiency of 90%. ""

82% Efficiency with a WTGO-3?

According to my Bacharach Insight Digital Analyzer, I could always get 88% with a carefully tuned and thoroughly cleaned or new WTGO-3 with a Carlin EZ-1. Which I would have gotten with a well tuned Riell0. If it said 82%, I would have known it was low and I could have gotten it up. Weil-McLain lists the -3 at 85.5% efficiency. 87% with a down fire and a damper. I always downfired. Don't lecture me on a drop on BTU's when down firing. Were discussing efficiency.

82% would be a WB or a V7 or 8 with a Beckett.

Gordy

Come on fellas we are here to help the poster that initiated this thread. This is starting to be like listening to a favorite song on the radio, and static takes over in the middle of it.

Harvey Ramers post really is the basis of what needs to be done at this point. Start from scratch, and do the math see what needs to be done to salvage the boiler. Whether it be insulation, or more emitters. I strongly urge the implementation of viessmanns low loss header with the sensor. There is some magic.

Also remember that the DOE of this boiler is 114 k everyone is basing on the 125k to the system. So what needs to be done is make sure you get the full 114k out to the system side, and get the heat loss with in, or below that number. Also make sure the emitters can distribute those btus.

Gordy

Again the 222-f is a fine boiler. While the ODR table shows the ability to go to 190 ish I think they are just projecting that curve beyond the temp output of the boiler.

If you carefully read the manual this all comes to light. Sometimes we read what we want to be, and disregard what we don't want. Together those elements paint the full potential of the product.

Efficiency is the goal! They are just going to say you are using the wrong product for the job. If you need those water temps then we have this boiler designed for that. Why spend the dollars on high efficiency if you want to use it in a design that does not allow its full potential.

SWEI

Hatterasguy said:

Viessmann must have a DT of 40 to deliver 125K. There isn't any other option.

No existing radiation is going to meet that figure.

Nor is it expected to. The physics of water-tube heat exchangers dictate (and Viessmann unambiguously documents) a properly implemented primary-secondary piping scheme. It's not rocket science.

Gordy

Okay most of us do not see rwt of 130 or less with a mod/con as a problem. IF you design around it as should be done .

I think part of the problem is everyone knows of the capability of the 100s, and 200s, and just assumed the 222 had the same programing in a combi package with out reading into the manual. An innocent mistake.

Gordy

Hatterasguy said:

And why would anybody design a boiler that has an output of 115K with a flow rate of only 6.5 GPM? Why would you do that? Is it your intention to force the installer to get the RWT down sufficiently?

In my opinion it's not with out some for site on viessmanns part. It is to be sure the appliance is running to its full efficiency potential. If you need higher water temps you need to use a boiler that will produce those temps at a lower efficiency.

I'm sure the German logic is why spend the money to buy our high efficiency product to use in a scenario that gives low efficiency results. We make a product for that type of install. Or if you want to use the 222-f then you need to get the envelope, and emitters in a high efficiency state. Forces someone to upgrade envelope, and emitters.


Here in the U.S. we spend the extra dollars for a mod/con, and throw it into a low efficiency scenerio( poor envelope, lack of radiation) then bump the water temps up to a temp that throws the boiler into a mid 80's efficiency because it has that capability. Sure it saves money with modulation, but it's only part of the full monte.

Paul48

It's Viessmann's desire to make boilers for homes that don't require one.

James Day_2

I feel like this site is loosing what it was intended for. It was meant to help people. It seems like all there is, is a lot of arguing over who is right and wrong. Viessmann is not for everyone, those who understand it can use it with success, but if you have never installed one, or it is your first time you should do the ample research to make sure it will fit the application. The vitodens 100 boilers where designed for more of a baseboard application where you can get the boiler temperatures up to around 180 degrees, the Vitodens 200's are designed for efficiency. If you need 180 degree water either add emitters or don't use the boiler, its pretty simple.

James

Paul48

He had his answers, long before the Viessmann defenders started arguing their merits. Everything after is just gobbled-gook.

Gordy

I don't think its all the company it could be German energy efficiency standards. Purely speculation on my part. Forcing someone into energy efficiency is not a bad thing the U.S. Should be more hard lined.

GW

James,

Well said. Yes if it were simple the OP would not be posting this type of question. If it were simple all boilers would work the same way. It would be simple if people would read the manual before installing the new boiler. It would be simple if heating guys got a heads-up when a new product doesn't do x y or Z, the way their other boilers operate.

I recall many years ago when the GB142 came out, we (my sales man) told a customer all the things the boiler would do. Unfortunately he was too familiar with the 2107 control and he didn't know the GB wouldn't do half the things the 2107 could do. ..... a stroke of dumb luck did not go our way. We assumed the new GB142 would do what the 2107 could do. The customer was very unhappy with us, we eventually made them happy but it wasn't easy. Of course we learned a hard lesson.

Anyway, your comment about "its pretty simple" isn't extremely helpful either. There are nuances that needed to be clarified as various comments were dropped in.

But alas I think we are all coming to a general concensus.

Gordy

James Day said:

I feel like this site is loosing what it was intended for. It was meant to help people. It seems like all there is, is a lot of arguing over who is right and wrong. Viessmann is not for everyone, those who understand it can use it with success, but if you have never installed one, or it is your first time you should do the ample research to make sure it will fit the application. The vitodens 100 boilers where designed for more of a baseboard application where you can get the boiler temperatures up to around 180 degrees, the Vitodens 200's are designed for efficiency. If you need 180 degree water either add emitters or don't use the boiler, its pretty simple.

James

Sometimes discussions can go into left field, but most of the time they can be healthy ones. Like Paul said the OP got an answer on steps to correct the situation.

In my opinion in comes down to budget. If you plan on insulating in the near future do that. If it's not in your plans then add more emitter. But it could be a combination of both. Maybe it will be cheaper to add emitters. The math will tell.

Play with the heat loss program. Do scenarios. If I just insulate the attic will that get my heat loss down in a reasonable water temp. If I do attic, and walls what happens. Just walls?

If insulation is in the future then it does not make sense to add emitter if insulating alone gets the system in a functional, and efficient state of operation.

Just sayin.

Gordy

Hatterasguy said:

Gordy said:

I don't think its all the company it could be German energy efficiency standards. Purely speculation on my part. Forcing someone into energy efficiency is not a bad thing the U.S. Should be more hard lined.

Have you noticed the plethora of large SUV's that consume fuel with abandon? $4.5K in fuel annually and this behavior has become accepted and routine.

The fuel consumption of one of these vehicles makes all of our discussions regarding squeezing the last percent of efficiency from a heating system a bit moot, don't you think?

Yup that's why I said the U.S. needs to be more hard lined. Now oil plummeted. Europe has not enjoyed such cheap fuel of any type ever hence their way of thinking.


As far as structures we missed the boat in the realestate bubble to really have a high percentage of energy efficient homes. Instead garbage no better, or even worse than past decades of envelopes flooded the land.

icesailor

My old dead boss once said. When we were erecting a Smith 2500 series boiler: "When you get to this level, you're supposed to know what you're doing.

I don't think that some completely understand the benefits of hydraulic separation whether through closely spaced tee's or hydraulic separators. Or the benefits of hydronic systems that are heavily and carefully zoned. Especially in colder climates where it gets to zero or below.

That Veissmann boiler as designed will work very well. The one that the OP has shown, should have had a hydraulic separator like Veissman surely recommends, where the boiler pump drives the boiler and the system pump drives the system. Not the system pump is driving the whole system. It wasn't designed that way. If the boiler needs 6 GPM through it to work properly, but the system is running anywhere from from 2 GPM to 10 GPM. the system will never run correctly. Let them all meet in a hydraulic separator and sort their issues out in private.

I've never seen a baseboard system with a 40 degree Delta T in my life unless it was 200' long active elements and running on gravity. If you are getting 40 degree Delta T's, someone made a mistake and went way beyond the envelope of the equipment.

Its like trying to take off in an overloaded airplane on a hot and humid summer day with little head wind. You get to the end of the runway and crash. Because you run out of ground effect air.

Turning down a zone on a zoned system on a cold day is the same as adding a higher temperature to the boiler and system. You just dropped the load. Just like you take your foot off the gas when you go over the crest of a hill.

We're talking a week or more of the coldest design weather? And the rest of the year/season, the system is grossly oversized?

Gordy

Hatterasguy said:

Ice, the photos of the system show a LLH installed. They can run the baseboard loops at a higher flow rate than the boiler.

Yes but there is no supply temp sensor hooked to it.

Rich_49

You need hydraulic separation and a Delta T pump on the system side . Set the Delta T at 20* for the heat emitters , this will guarantee an average water temp of 155* through the emitters that are piped in series . That will be your top end and insulate the house , the faster you do the faster you'll increase your efficiency and comfort .
* The only PROBLEM with Veissmann is that they believe designers and installers should have a friggin clue and know how to design and select equipment . Not really a Veissmann problem as much as a problem with how we educate our contractors or how we don't .
* You may want to think about changing out the emitters to Smiths Heating Edge , more output , lower temp . I'd be willing to bet you lack the proper amount of emitter on top of insisting on a machine that is designed well beyond your chosen installers' capabilities .

Gordy

Hatterasguy said:

If the RWT is 145° to the boiler, the maximum output of the boiler will be 65K BTUH.

This is exactly the mistake that most will make with this boiler and exactly what I mentioned above.

You can run a 20DT at the emitters, but the SWT must be 150°F. and the AWT must be 140°F. Then you get 114K BTUH.

Huh?