Viessmann 222-F freeze protection...

Skyline

It's been three month that 222-F had been installed in my ranch-style house, with no basement. The boiler is in a 4' x 5' small room, call it a boiler-room from here on, it is part of the house like a closet.

The boiler-room does not have its own radiator/baseboard, but the temperature in the room does not fall under 60F. Most of the times, the temperature in the boiler-room is higher than that.

For the first couple of month the boiler operated in a predictable fashion. The thermostats in either of the two zones call for heat, once the set room temperature reached, the boiler would shutoff after couple of minutes. The DHW operated in similar manner.

As of late, when the outdoor temperature is under 37 F and the room temperature(s) reached, the boiler does not shut off. The fan stays running with the burner turning on occasionally for a short period of time. This is the explanation of the reason from my contractor, quote:

According to Viessmann the boiler is doing exactly what it was designed to do. I talked with them this morning. I was correct in assuming it had something to do with the freeze protection. Under 37 degree the fan comes on. They claim that they want it to run all the time under 37 it is also making water for the reserve tank but at a extremely low firing rate instead of making the boiler fire to high fire. They assured me it is doing what it was designed to do

Why would the 222-F have 20 gallons, well insulated DHW reserve tank in this boiler, if the system need to continiuosly heat the water in the reserve tank? It is only at the time, when the outdoor temperature is under 37F.

The boiler is within the house, why is the freeze protection activated?

Just the containiously running fan in 24 hours uses ~ 3 KWh during this time, just like in the case of yesterday. The burner running power utilization is additional to this. Under normal circumstances, when the outdoor temperature is over 37 F, the boiler uses about 0.5 KWh. The freeze protection may effectively offsets any energy efficience that the boiler may have in NG.

Is there a way to disable the freeze protection? If not, can the outdoor temperature be set to a more reasonable value, like 33 F, or less?

TIA...

Skyline

After further review, proceed at your own risk...

The freeze protection kicks in @34F and shuts off @37F. If and when the outdoor temperature stays at or under 34F, the boiler stays running, drawing ~140W/h all day/night. This may not seems much and it's not, but when there is a cold snap, the impact of that shows up in the utility bills.

Here's the first three month energy utilization for the Veissmann boilet; yes, both electricity and NG:



In general, the Veissmann boiler does utilize more power and less NG, when compared to the previous cast iron boiler. The estimated $250/y saving may reach around $2,500 in ten year, but remains to be seen.

The December power utilization really shows the impact of freeze protection. Most of the nights in this month, the temperature had been under 34F, sometimes even during the day the temperature didn't go over 36F.

Since it is a NG boiler, the energy saving does not take in to account the power utilization. At least that is what the head of Veissmann stated:

The 95% efficiency is based on fuel usage not electrical consumption. The ratings are also based on operating conditions that promote maximum flue gas condensation. This requires the return temperatures to the boiler to be below 85F.

That is false on number of ways....

One is, electricity is an energy source too. Not accounting for it in the efficiency rating is just being dishonest.

Two, how the hell is someone going to heat the house with CI radiators and baseboard with that return water temperature? Especially for "this old house" with with the given heat-loss ratio. If you said "no way", you'd be right...

With all that stated...

I still love my Veissmann boiler. Would I have choosen CI boiler with 80-85% efficiency rating, if I had know how the actual efficiency in my circumstances? The chances are yes, especially knowing that the cost difference with the high efficiency boiler will not be an ROI to boast about.

But that's not what any of the installers I've dealt with would emphasize; rather, they'd talk about the 95% or more efficiency rating, how the additional cost will be recovered, etc. None of them stated that "This will be your most expensive option during its lifetime.".

It seems to me, that the boiler business is a dishonest business from all around. Starts with the efficiency rating system, continues with the manufacturers and the installers. At least from the perspective of the owner of "this old house"...

psb75

The Viessmann 222F boiler is an amazing machine. The return water does not have to be 85F to condense. Condensation happens with return water at anything below 130F. I have this boiler in a 165 yr. old 2500 s.f. farm house with 20 C.I. radiators and it runs beautifully, on ODR and with no interior wall thermostats. I can't understand why your "freeze-protection" feature is even being activated?

Skyline

@psb75...

Yes, the Viessmann 222F is an amazing machine, and I do love it. The boiler is quite, unlimited DHW and the house is comfortable; no more indoor temprature swings, it is "even-steven".

My house has two zones with their own thermostats that calls/ends heat for the zone in question. My house is ~70 years old with seven CI and one baseboard radiators; yes, the boiler is oversized due to DHW requirements. I've decreased the setback temps, once I've learned about the frost protection. No reason for having it run all night, drawing 140W/h, when I can maintain the desired temperature with an additional 50-60W for heat on occasion when needed.

I don't like the freeze protection, rather frost protection as the On-Board Vitotronic 200, HO1B Control manual states:



Why does the frost protection needs to be active, if boiler is in a small room in a ranch-style house is beyond me. Especially when this small room is part of the house and the temperature should never drop below 50-60F even, if it is not heated.

Maybe I should move the outdoor temperature sensor indoor, set the heating curve to the max, or just set min/max boiler temperature and forget the heating curve. At least the frost protection would never be activated again.

Makes me curious, if my boiler doesn't have a UPS backup and stand-by generator, how would Veissmann protect my boiler during power failure since they are so concerned about frost protection.

Would they come around with a generator to prevent the boiler from getting frost build up? I think they would not...

Skyline

I forgot to add my thaughts about the condensation...

Yes, the boiler will condense, if and when the return water temperature is between 85-130F, The highest efficiency is 95% @85F.

As the return water temperature is increasing, the efficiency drops like a brick. By the time it reaches 130F, the efficiency is probably around 85% by that time. Just like a non-condensing, high efficiency CI boiler.

CI and baseboard radiators are really not a well suited media for condensing boilers. At least that's what I've learned with the new boiler.

On the other hand, getting DHW from a combi, condesing boiler will cost less than getting it from similar CI boiler.

There's always a trade off...

heathead

The Viessmann Manual should have changes that can be made to change the temperatures for the Frost settings. I suggest you study the manuals very carefully. Write down all setting before you change things. I have not looked at the 222 manual, but the 200 has many settings, way more advanced that most installer's setup. Very customizable for the house or building, which is why people like the viessmann. As has been said depending upon the available heat emitters. Most of the time even with baseboard you should have not to run high temps all but the coldest day of the year. This takes time to adjust and get thing prefect.

Skyline

@heathead...

You are probably referring to the service instruction, that describes code changes, specifically for frost protection settings:

In which case, this home owner knows that changing factory codes is above his head by a large margin. It's certainly not a good idea to mess with it, especially in the middle of the winter.

It just irks me, that this sophisticated boiler is running with factory setting, instead of being taylored to my circumstances and needs. It's on the installer, not on Veissmann, but the end result is the same.

Anyone knows an installer in Lower Fairfield County in CT, who can actually change factory codes in the Viessman boiler?

TIA...

Alan (California Radiant) Forbes

Have you tried the contractors listed on the Viessmann website?

https://myviessmann.com/contact-a-vipro/

Skyline

Thanks @Alan(CaliforniaRadiant)Forbes...

I did now, but only one local pro, no web presence and very little public information about the company. I'll look in to the company and will reach out to the Viessmann's technical service manager in my area to find one.

psb75

Depending on your area, support for Viessmann CAN be difficult.
I am struggling with that right now. (Have been for the entire holiday period). They are NOT OPEN until Monday morning, and I can guarantee there will be a l-o-n-g phone line que at tech. support. They have a recorded message saying that because of Covid 19, many of their "techs are in the field and ph. lines are understaffed." Parts are difficult to obtain at supply houses as they often aren't stocked. Must be ordered from RI. Viessmann is very good equipment. Their support is good...where it exists.

Alan (California Radiant) Forbes

During COVID, you have to text tech. support at (800)288-0667 with your case number and the problem you're having.
If you don't have a case number, text them the model and serial number of your boiler, your contact information and the location of the boiler and they will give you a case number to reference in the future.

I think it's difficult finding qualified Viessmann tech's. because installers want to install, not service, so they don't get into the minutiae of coding.

@Skyline: I'm impressed at your level of understanding of your boiler and the documentation you've done on energy consumption. Stick around.

GW

So the installer bailed? Maybe I missed that part 

psb75

Alan (California Radiant) Forbes, thanks for that info. I have had a case # for a few years now. Boiler is now 10 years old. Seems like the PCB might have gone out---before Xmas. Now hard to get parts.
Rural s.e. MI does not have good Viessmann residential support. Its kind of Viessmann 'fly-over' country. Not a lot of sales. Or density of V. boilers. Ironically, there is a very large Viessmann wood chip boiler in a nearby university though.
More irony: Viessmann largest boiler mfg....in the world.

Skyline

Thanks for the compliment @Alan (California Radiant) Forbes ...

I've been texting with Viessmann text support for three month by now, on and off; my boiler is four month old. If you'd say, that they know me by know, including the area rep and service manager, that would be an understatement.
The text support is rather limited for home owners, quote:

For Liability reasons, tech support can only help with very limited operating issues with homeowners. These include changing heating curves, room temperature, DHW setpoint, and other settings that are desired by the homeowner, When changes are requested that could cause harm to the individual or the property, we will not take on that risk. We leave this to the installing or service contractor. They know the property better than we can know it, so the liability falls on them.

I've learned the "very limited operating issues" from my installer on day one. Despite this, I still contact them and have them create a ticket #, that my installer can address with them.

My installer didn't bail on me, I actually like him and the work he's done. He and his crew are probably the same as most crews; great installers, but not much knowledge on customizing the boiler setting for the installed location. The perceived complexity and liability that comes with it certainly will prevent most installers to get involved with customization.

Seemingly, the plumbing and computer business has merged, creating an environment, that isn't really great for their customers. On one hand, boiler manufacturer utilizing "smart devices" for increasing boiler efficiency. One the other hand, installers (glorified plumbers) know hardware installation, but shy away from doing much on the boiler's control interface.

With my background, I seriously consider taking some of the classes at the Viessmann Academy, mainly about how to customize the boiler settings for my circumstances. Reading the service instruction manual is one thing, understanding the overall impact(s) of the changes is entirely other. I'll call them next week to see my options...

GW

Ok that’s a bummer, your heating guy can’t even opine on the freeze protection settings. I’d drop that setting and take a peek at it on super cold mornings. With all that said, most homeowners aren’t as critical-thinking as you are, looking at every watt. 

plumbers and computers—- kind of a wide net comment, and I don’t disagree. I’m a 1980s era plumber yet for the last 10 years I have identified myself as an hvac guy. Many plumbers seem to enjoy (or tolerate) the old stereotype. Gotta be nice to the plumbers though- when you (homeowner) need one, you need one. 

Also, 95%—- I have a polite paragraph in my agreements discussing that very fact. I never want a homeowner coming back to me saying their system isn’t “actually 95%”. Viessmann didn’t set the rules on AFUE. That’s the official rating. 

Jamie Hall

I can't resist commenting, @Skyline , on a problem which you have raised -- and which is not limited to heating systems. More and more systems -- heating, cars, tractors, airplanes, you name it -- have rather sophisticated computers embedded (sometimes a dozen or more -- you car, for instance), all running more or less complicated programs (apps, codes, whatever...). Of necessity, these interface with mechanical components and the real world. The problem is that the folks, most of them very bright and clever people, have seldom if ever actually been in the field (or even the real world!) -- while the people in the field aren't able to get access to, never mind change, the programs which are running. The result is programs which look wonderful, and work well in the necessarily limited test environments, but simply can't adapt to the far wider field variations. There is, unhappily also a definite arrogance among the programming (coding) fraternity which makes it difficult for them to accept feedback from the real world.

Add to that the very real and well founded concern about liability suits when field modifications -- even to control parameters -- are permitted (not only civil suits by individuals, but class actions, never mind some Federal or State regulatory agency getting after you), and you get the kind of situations to which you refer.

Skyline

@GW...

I am and been nice to my plumber, that's not going to change...

Agreed, that Viessmann didn't set rules (arguable at best) on AFUE. On the other hand, the boiler manaufacturers lobbyist(s) probably written, or at the very least, had to aggree to the rules. That's how it works in the US most of the times...

The 95% AFUE is a dream for most installation. With that stated, the new boiler did reduce NG utilization in my case. While the posted saving percentages are influenced by outdoor temperature and other factors, it is there.

I was just ticked off that frost protection actually increased the power utilization, that effectively offset the savings in NG by about 10% in three month. Even if my boiler had been running at 95% efficiency, which it did not, the 10% increase in power utilization during this period reduced the overall efficency to 85%. The more likely scenerio that the boiler operated roughly in 85-90% efficiency range, putting the overall efficiency in to the 75-80% range.

GW

well I tip my hat that you actually pay attention to that level of detail.

At times i chuckle when i see jobs with an array of Taco 007 pumps lined up like an arcade shooting gallery. Those things drink about 80 watts or so each. I once did a higher end radiant job maybe 12 years ago. 3 different temps, so i did 3 injection-style control systems with Tekmar. Do the math- 6 pumps! I would not do the same today. Everything has its cost though. Floating mixing vales/actuators are not cheap either- a classic 'pay now or pay later' situation.

In our area, the rebates are so large for hi-efficiency, it's less money to do that than it is for a cast iron boiler.

It's a funny world. if a car dealership has a couple of one or two year old cars up on the rack, no one has a melt down. When a one or two year old boiler has a servicing issue, things get spicy! But that's why i love this trade, installing new stuff and 'having conversations' with the homeowners. Most of them like me

Skyline

@GW...

That depends on the Taco pump, there are high energy efficient rated models.

As stated earlier in this thread, the frost protection utilizes ~140W/h without activating the zone circulators. If and when both room thermostats call for heat and the boiler turns on the circulators, the highest power utilization I've seen was 230W/h, reading from the UPS backup for the boiler.

Just a minor disagreement...

I wish you've installed my boiler, even if it would have taken a day longer with all of the conversation we would've had....

psb75

Instead of a large "shooting gallery array" of 007's why not primary/secondary piping or LLH with an ECM circulator and zone valves? There are often rebates on the ECM circulators. Let the "95% boiler" do its own fossil-fuel savings --if it is plumbed-in and set-up well--and installed in the right application.

GW

Ha! my 007 comment was anecdotal fer sure. We use the Grundfos Alpha pumps. The watts pull no more than 40 or so. One large system we did recently- big pipes, it was pulling about 12 I recall. Small systems- we use zone valves.

@Skyline just kick the setting to the curb. If you freeze your boiler, you will be the 1st that i have ever heard of. Virtually impossible. If you lose power, then all bets are off (in that case your anti-freeze function is null and void anyway)

Skyline

@Jamie Hall...
Sometimes, embeded systems also kill people, looking at you BOEING...

@psb75...
My old boiler had the manifold for the two zones, it was easier and cheaper to tie in the new boiler to it.

@GW...
In retrospect, I'd probably would have different setup for the boiler, but it's too late by now.

In addition to the UPS backup, the house also have a stand-by generator. It's unlikely that there would be any freezing for my boiler.

In the middle of the winter, I won't kick the setting to the curb. On the other hand, this setting won't be around by the next winter. It'll be interesting to see the difference in the utility bills between the two settings...

Jamie Hall

or Airbus, @Skyline ...

Skyline

@Jamie Hall...

Touche... even if there's a difference between hardware failure and embedded systems...