I've put in about 60 of these boilers doing residential new construction houses using the primacy secondary loop method. Never understood for it worked until now. Thank you, really excellent explanation.
thank you very much for posting this tutorial ,this is the best explanation of condensing boilers i have seen ,the lost art of technical manuals writing is alive and well at viessmann!
Thanks for having this video up. It explains a bunch of concepts that the typical babyboom gen HVAC contractor still frowns at me when I try to explain them issues with condensing units and hydraulic seperation.
ive been trouble shooting and repairing boilers for 8 years. This video gives you a great explanation of how everything works together. hope you give videos on heat loss and sizing. Also more in depth piping
Robert, The German alphabet equivalent to the combined SS is not available in the English alphabet. To represent this SS sound they use the character listed in the description below. This is the reason why a lot of German words use the SS. Taken from Wikipedia: "In German orthography, the grapheme ß, called Eszett (IPA: [ɛsˈtsɛt]) or scharfes S (IPA: [ˈʃaɐ̯fəs ˈʔɛs], [ˈʃaːfəs ˈʔɛs], lit. "sharp S"), represents the [s] phoneme in Standard German, specifically when following long vowels and diphthongs, while ss is used after short vowels. " I hope this clarifies your curiosity.
When the Vitocrossal 300 CU3A is piped as shown at 30:06 for a one temp zone installation, does the circulator need to run continuously for outdoor reset to function properly?
Hi Shahrdad, Because the Vitocrossal 300 CU3A boiler is a high mass boiler, with a water content between 13-18 USG, depending on the model size, constant circulation through the boiler is not required as it is with Vitodens. If the pump in the image is configured as a heating circuit 1 pump it will by default run whenever the OAtemp is below the WWSD setting (Warm Weather Shut Down). If the pump shown is configured as a Zone circuit pump (The Zone Circuit configuration was not available when this webinar was produced. It was added as a control feature later), the pump and call for heat will cycle with the operation of the thermostat assigned to the zone. In either case the boiler operation is not necessarily connected to the pump operation but the call for heat. If you were to control the pump independent from the boiler it will maintain the setpoint regardless of the pump operation.
@@marknorris9722 Thank you Mark. What I had in mind is a one-zone converted gravity system, possibly with indirect DHW added on. One of the things I like about this boiler is that no dedicated boiler pump is needed. So what I’m understanding is that once the Outdoor Reset detects temps lower than Warm Weather Shut Down, it will tell the pump to run constantly, in order to maintain a uniform temp throughout the system, and the boiler will fire as needed to maintain the proper temperature according to the outdoor reset curve. And if DHW is also added as a second zone, the main circulator will shut down and the DHW pump will flip on when the DHW tank needs to be heated. I’m curious, but if an ECM pump is used as the main circulator, does the boiler vary the output of the pump, or will it run at a constant rate? Again, thank you for your reply.
@@Shahrdad Yes, you are correct, if the system is configured as Heating Circuit 1 without thermostat control of the boiler. If you used a Zone Circuit, the pump and call for heat will follow the thermostat call. There is a 0-10VDC pump speed control logic available, but it is limited to the operation of a boiler pump if configured. It also requires that a connector for that plug is ordered as an accessory part because it does not come with the boiler. How it works is that the control 0-10VDC signal is based on the outdoor temp. As it gets colder outside the pump runs faster. We do not use this function a lot on our North American systems. It would also require the use and configuration of a common supply (LLH) sensor. As to your DHW comment, if DHW is configured as priority, which is the default, the boiler setpoint will go to the DHW setpoint and the DHW pump @ output 21 by default, will start. The heating circuit 1 pump will shut down during a DHW call. If you switch to non-priority DHW, both pumps will operate simultaneously and the boiler set point will be the greater of the two setpoints
@@marknorris9722 Thank you Mark! That was very helpful. On the Viessmann North American site, I don’t see any of the Vitotrol thermostats listed at all. When you install these systems, how does the system know that the indoor temp set on the outdoor reset actually achieves the desired temperature indoors? My understanding is that a regular Honeywell or Nest thermostat doesn’t function properly with this system.
@@Shahrdad Yes, you are correct, if the system is configured as Heating Circuit 1 without thermostat control of the boiler. If you used a Zone Circuit, the pump and call for heat will follow the thermostat call. There is a 0-10VDC pump speed control logic available, but it is limited to the operation of a boiler pump if configured. It also requires that a connector for that plug is ordered as an accessory part because it does not come with the boiler. How it works is that the control 0-10VDC signal is based on the outdoor temp. As it gets colder outside the pump runs faster. We do not use this function a lot on our North American systems. It would also require the use and configuration of a common supply (LLH) sensor. As to your DHW comment, if DHW is configured as priority, which is the default, the boiler setpoint will go to the DHW setpoint and the DHW pump @ output 21 by default, will start. The heating circuit 1 pump will shut down during a DHW call. If you switch to non-priority DHW, both pumps will operate simultaneously and the boiler set point will be the greater of the two setpoints
Thank you for the video. I am installing my first vitodens today and there is one thing i cannot figure out: how do I wire my secondary pumps to the boiler, so it can shut them off automatically. I have the 4-pipe condensing boiler. Thank you
I think you would wire your secondary pumps to a zone control box or switching relay and wire the primary pump to the boiler. But I'm not too familiar with Viessmann products.
This winter i urgently had to replaced my old 50 gal gas water heater with the same capacity water tank. We have three showers and during Christmas we run out of hot water quickly. Is it safe to connect the cold water line to the tankless water heater input and connect the output of the tankless water heater into the input of the 50gal water heater tank and continue to used it as a reserve tank?
Pete Diaz I think that would be fine. The storage tank would add some money to the heat bill but the majority of energy expended on a water tank is raising the initial cold water temp. If the tank is well insulated it should not add too much extra expense. I also have an extra storage tank that runs off a heat exchanger from the boiler. The storage tank may add a percentage to the bill (20%???) but the hot showers will last a bit longer.
All I have is 1 zone for forced air furnace. Installer put closely spaced tees, and my boiler circulating pump is on the supply side of the closely spaced tees. Everything works fine, but wondering if that circulating pump should be on the return side of the closely spaced tees.
Ben, If you are using a low mass boiler like the Viessmann Vitodens 100 or 200 series boilers then the pump should be pumping into the boiler return. If you are using a high mass boiler like the Viessmann Vitocrossal 300 CU3A then it is not critical. The description of low or high mass will indicate the water volume content of the boiler. A low mass boiler has very little water inside and therefore requires forced circulation for the burner to operate. Pumping the water into the boiler allows the head the pump generates to overcome the resistance in the boiler's heat exchanger and reduce the chanced of pump cavitation. In high mass boilers flow is not required for burner operation and the pressure drop across the heat exchanger is low. With high mass boilers we will typically follow the practice of pumping away into the system to use the head of the pump to overcome the building head. Primary/Secondary piping like a low loss header or closely spaced tees are not normally required with high mass boilers. In your case you have closely spaced tees installed so the boiler pump only will need to deal with the boiler head. If your boiler is low mass, pump into the boiler. If your boiler is high mass, it shouldn't matter as far as boiler operation goes.
At 49:30, application 6, Could you just prioritize the zone pump for domestic hot water off the secondary loop. Not sure why that wasn't considered an option
Arne, If you are asking if DHW can still be priority in this application, yes it can, if the pump management device controls the P2, P3 and P4 pumps. The Vitodens 200 series of boilers can control all the pumps shown directly from the boiler. In addition, the DHW set point and tank sensor are also part of the boiler logic. In priority mode the boiler will start P2, go to the DHW set point parameter and shut down P3 & P4 while disabling their set point command. If you were using the Vitodens 200 series boilers, it would be simpler and more cost effective to pipe the DHW tanks on the primary side, similar to the piping example @ 43:24 of the video. If you use a boiler like the Vitodens 100 series shown in this video, which always has “DHW priority”, then to control these pumps you need a third party multizone control that can separate not only priority but also the command for the priority zone, in this example DHW, so the boiler can operate at the DHW set point when DHW calls. This set point is most likely different from the heating loop set points. In that case P2 would start and P3 & P4 would shut off on DHW call through the multizone control and a binary command from the multi zone control to the boiler’s DHW connection would tell the boiler to adjust the set point to suit. This video was produced before the current model of Vitodens 100 B1HA was available. With the new B1xx generation Vitodens 100, you can pipe application #2 shown @ 43:24 without the P1 & P2 pumps because the boiler includes a built-in pump that can be diverted through the internal diverting valve to either the Low loss header or the DHW tank. This is shown in the updated guide application guide’s application #2 for Vitodens 100 published as 579-5123 (Vitodens 100-W B1HA/B1KA residential boiler) available online @ www.viessmann.ca
The dew point of the flue gas is a function of the laws of physics regarding the dew point of water. Water vapour in the flue gas will be forced to change state into water droplets at the dew point of the water. However there are several thing that effect the dew point. Relative humidity in the air, the altitude above sea level or the barometric pressure to name the three most prominent. The fuel burned does not change this point. The potential volume of condensate may vary because of the volume of air required for combustion is different with different fuels. One fuel related thing that does effect the dew point is the amount of CO2% in the flue gas. The lower the CO2% (Resulting from more excess Air) in the flue gas the lower the dew point. This is why with the Viessmann premix burner we set them up for the most part at the factory to keep the CO2 levels and thus the dew point higher. For optimum efficiency we would set the burner up with zero % excess air, but for safety reasons that is not done. At zero % excess air the production of CO is likely due to the unstable environments the burner operates in and that is not safe.
Copies of the Application Guides that this video is based on are available as pdf files @ www.viessmann.ca .Look under the Prologin tab, then inside the current documentation area. There you will find all documentation listed by boiler model. Look for the Application Guide files under the products.Currently there are Application Guides for Vitodens 100 WB1B, Vitodens 100 B1xA, Vitodens 200 B2Hx and Vitodens 222F B2TB models.For a hard copy of an Application Guide contact your local Viessmann Sales Rep. There is not cost for these guides.If you don't know who your rep is, you can find them on the website under contacts.
HOW COME YOU IN STALL CIRCULATE PUMPS ON THE HOT SIDE OUT PUT WHEN THE WATER IS FULL EXPANDED AND LOADED WITH AIR. BUT YOU INSTALLED PUMPS ON COLD SIDE FOR HOT WATER HEATER PUMP WILL LAST LONGER ZONE VALVES TOO
I've put in about 60 of these boilers doing residential new construction houses using the primacy secondary loop method. Never understood for it worked until now. Thank you, really excellent explanation.
Wow, you installed the same system in 60 homes and didn't even know how it worked, that doesn't exactly inspire confidence in your trade, nor you.
thank you very much for posting this tutorial ,this is the best explanation of condensing boilers i have seen ,the lost art of technical manuals writing is alive and well at viessmann!
Thanks for having this video up. It explains a bunch of concepts that the typical babyboom gen HVAC contractor still frowns at me when I try to explain them issues with condensing units and hydraulic seperation.
Thank you for this video! It was sure a help in deciding how to design my system, and then it was a help in interacting with my contractor.
ive been trouble shooting and repairing boilers for 8 years. This video gives you a great explanation of how everything works together. hope you give videos on heat loss and sizing. Also more in depth piping
Excellent video thank you for sharing
Allen Hart can you hallep me I'am Palmer plise
Very well put together video, thank you.
good video explains choices for applications
Robert,
The German alphabet equivalent to the combined SS is not available in the English alphabet. To represent this SS sound they use the character listed in the description below.
This is the reason why a lot of German words use the SS.
Taken from Wikipedia: "In German orthography, the grapheme ß, called Eszett (IPA: [ɛsˈtsɛt]) or scharfes S (IPA: [ˈʃaɐ̯fəs ˈʔɛs], [ˈʃaːfəs ˈʔɛs], lit. "sharp S"), represents the [s] phoneme in Standard German, specifically when following long vowels and diphthongs, while ss is used after short vowels. "
I hope this clarifies your curiosity.
very informative, thanks for sharing
Very well explain!
excellent video , really informative and thanks ,
When the Vitocrossal 300 CU3A is piped as shown at 30:06 for a one temp zone installation, does the circulator need to run continuously for outdoor reset to function properly?
Hi Shahrdad,
Because the Vitocrossal 300 CU3A boiler is a high mass boiler, with a water content between 13-18 USG, depending on the model size, constant circulation through the boiler is not required as it is with Vitodens.
If the pump in the image is configured as a heating circuit 1 pump it will by default run whenever the OAtemp is below the WWSD setting (Warm Weather Shut Down). If the pump shown is configured as a Zone circuit pump (The Zone Circuit configuration was not available when this webinar was produced. It was added as a control feature later), the pump and call for heat will cycle with the operation of the thermostat assigned to the zone. In either case the boiler operation is not necessarily connected to the pump operation but the call for heat. If you were to control the pump independent from the boiler it will maintain the setpoint regardless of the pump operation.
@@marknorris9722 Thank you Mark. What I had in mind is a one-zone converted gravity system, possibly with indirect DHW added on. One of the things I like about this boiler is that no dedicated boiler pump is needed. So what I’m understanding is that once the Outdoor Reset detects temps lower than Warm Weather Shut Down, it will tell the pump to run constantly, in order to maintain a uniform temp throughout the system, and the boiler will fire as needed to maintain the proper temperature according to the outdoor reset curve. And if DHW is also added as a second zone, the main circulator will shut down and the DHW pump will flip on when the DHW tank needs to be heated.
I’m curious, but if an ECM pump is used as the main circulator, does the boiler vary the output of the pump, or will it run at a constant rate? Again, thank you for your reply.
@@Shahrdad Yes, you are correct, if the system is configured as Heating Circuit 1 without thermostat control of the boiler.
If you used a Zone Circuit, the pump and call for heat will follow the thermostat call.
There is a 0-10VDC pump speed control logic available, but it is limited to the operation of a boiler pump if configured. It also requires that a connector for that plug is ordered as an accessory part because it does not come with the boiler. How it works is that the control 0-10VDC signal is based on the outdoor temp. As it gets colder outside the pump runs faster. We do not use this function a lot on our North American systems. It would also require the use and configuration of a common supply (LLH) sensor.
As to your DHW comment, if DHW is configured as priority, which is the default, the boiler setpoint will go to the DHW setpoint and the DHW pump @ output 21 by default, will start. The heating circuit 1 pump will shut down during a DHW call. If you switch to non-priority DHW, both pumps will operate simultaneously and the boiler set point will be the greater of the two setpoints
@@marknorris9722 Thank you Mark! That was very helpful. On the Viessmann North American site, I don’t see any of the Vitotrol thermostats listed at all. When you install these systems, how does the system know that the indoor temp set on the outdoor reset actually achieves the desired temperature indoors? My understanding is that a regular Honeywell or Nest thermostat doesn’t function properly with this system.
@@Shahrdad Yes, you are correct, if the system is configured as Heating Circuit 1 without thermostat control of the boiler.
If you used a Zone Circuit, the pump and call for heat will follow the thermostat call.
There is a 0-10VDC pump speed control logic available, but it is limited to the operation of a boiler pump if configured. It also requires that a connector for that plug is ordered as an accessory part because it does not come with the boiler. How it works is that the control 0-10VDC signal is based on the outdoor temp. As it gets colder outside the pump runs faster. We do not use this function a lot on our North American systems. It would also require the use and configuration of a common supply (LLH) sensor.
As to your DHW comment, if DHW is configured as priority, which is the default, the boiler setpoint will go to the DHW setpoint and the DHW pump @ output 21 by default, will start. The heating circuit 1 pump will shut down during a DHW call. If you switch to non-priority DHW, both pumps will operate simultaneously and the boiler set point will be the greater of the two setpoints
Thank you for the video. I am installing my first vitodens today and there is one thing i cannot figure out: how do I wire my secondary pumps to the boiler, so it can shut them off automatically. I have the 4-pipe condensing boiler. Thank you
khum kumar
Great video very useful thank you
I think you would wire your secondary pumps to a zone control box or switching relay and wire the primary pump to the boiler. But I'm not too familiar with Viessmann products.
it is awsome
This winter i urgently had to replaced my old 50 gal gas water heater with the same capacity water tank. We have three showers and during Christmas we run out of hot water quickly. Is it safe to connect the cold water line to the tankless water heater input and connect the output of the tankless water heater into the input of the 50gal water heater tank and continue to used it as a reserve tank?
Pete Diaz I think that would be fine. The storage tank would add some money to the heat bill but the majority of energy expended on a water tank is raising the initial cold water temp. If the tank is well insulated it should not add too much extra expense. I also have an extra storage tank that runs off a heat exchanger from the boiler. The storage tank may add a percentage to the bill (20%???) but the hot showers will last a bit longer.
All I have is 1 zone for forced air furnace. Installer put closely spaced tees, and my boiler circulating pump is on the supply side of the closely spaced tees. Everything works fine, but wondering if that circulating pump should be on the return side of the closely spaced tees.
Ben,
If you are using a low mass boiler like the Viessmann Vitodens 100 or 200 series boilers then the pump should be pumping into the boiler return. If you are using a high mass boiler like the Viessmann Vitocrossal 300 CU3A then it is not critical.
The description of low or high mass will indicate the water volume content of the boiler.
A low mass boiler has very little water inside and therefore requires forced circulation for the burner to operate. Pumping the water into the boiler allows the head the pump generates to overcome the resistance in the boiler's heat exchanger and reduce the chanced of pump cavitation.
In high mass boilers flow is not required for burner operation and the pressure drop across the heat exchanger is low. With high mass boilers we will typically follow the practice of pumping away into the system to use the head of the pump to overcome the building head. Primary/Secondary piping like a low loss header or closely spaced tees are not normally required with high mass boilers.
In your case you have closely spaced tees installed so the boiler pump only will need to deal with the boiler head.
If your boiler is low mass, pump into the boiler. If your boiler is high mass, it shouldn't matter as far as boiler operation goes.
do you have a book with all of this,? please let me know ?
Locul 1!!!
At 49:30, application 6, Could you just prioritize the zone pump for domestic hot water off the secondary loop. Not sure why that wasn't considered an option
Arne,
If you are asking if DHW can still be priority in this application, yes it can, if the pump management device controls the P2, P3 and P4 pumps.
The Vitodens 200 series of boilers can control all the pumps shown directly from the boiler. In addition, the DHW set point and tank sensor are also part of the boiler logic. In priority mode the boiler will start P2, go to the DHW set point parameter and shut down P3 & P4 while disabling their set point command.
If you were using the Vitodens 200 series boilers, it would be simpler and more cost effective to pipe the DHW tanks on the primary side, similar to the piping example @ 43:24 of the video.
If you use a boiler like the Vitodens 100 series shown in this video, which always has “DHW priority”, then to control these pumps you need a third party multizone control that can separate not only priority but also the command for the priority zone, in this example DHW, so the boiler can operate at the DHW set point when DHW calls. This set point is most likely different from the heating loop set points.
In that case P2 would start and P3 & P4 would shut off on DHW call through the multizone control and a binary command from the multi zone control to the boiler’s DHW connection would tell the boiler to adjust the set point to suit.
This video was produced before the current model of Vitodens 100 B1HA was available. With the new B1xx generation Vitodens 100, you can pipe application #2 shown @ 43:24 without the P1 & P2 pumps because the boiler includes a built-in pump that can be diverted through the internal diverting valve to either the Low loss header or the DHW tank. This is shown in the updated guide application guide’s application #2 for Vitodens 100 published as 579-5123 (Vitodens 100-W B1HA/B1KA residential boiler) available online @ www.viessmann.ca
What is the dew point of propane? You show at the 24 minute mark the dew point of natural gas is 130 degrees. But I only have propane available.
The dew point of the flue gas is a function of the laws of physics regarding the dew point of water. Water vapour in the flue gas will be forced to change state into water droplets at the dew point of the water.
However there are several thing that effect the dew point. Relative humidity in the air, the altitude above sea level or the barometric pressure to name the three most prominent. The fuel burned does not change this point. The potential volume of condensate may vary because of the volume of air required for combustion is different with different fuels. One fuel related thing that does effect the dew point is the amount of CO2% in the flue gas. The lower the CO2% (Resulting from more excess Air) in the flue gas the lower the dew point. This is why with the Viessmann premix burner we set them up for the most part at the factory to keep the CO2 levels and thus the dew point higher. For optimum efficiency we would set the burner up with zero % excess air, but for safety reasons that is not done. At zero % excess air the production of CO is likely due to the unstable environments the burner operates in and that is not safe.
Copies of the Application Guides that this video is based on are available as pdf files @ www.viessmann.ca .Look under the Prologin tab, then inside the current documentation area. There you will find all documentation listed by boiler model. Look for the Application Guide files under the products.Currently there are Application Guides for Vitodens 100 WB1B, Vitodens 100 B1xA, Vitodens 200 B2Hx and Vitodens 222F B2TB models.For a hard copy of an Application Guide contact your local Viessmann Sales Rep. There is not cost for these guides.If you don't know who your rep is, you can find them on the website under contacts.
how much does the book cost ?
What hot water line to run your hot water overhead
HOW COME YOU IN STALL CIRCULATE PUMPS ON THE HOT SIDE OUT PUT WHEN THE WATER IS FULL EXPANDED AND LOADED WITH AIR. BUT YOU INSTALLED PUMPS ON COLD SIDE FOR HOT WATER HEATER PUMP WILL LAST LONGER ZONE VALVES TOO
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+Sadhana Srivas what ?