Danfoss ESBE Valves

offdutytech

We seem to install more cast iron boilers than Modcons at the request of customers to keep things simple. It's been in the back of my mind on the past few service change outs of these systems to try something other that just a fixed bypass and throttling valve on the systems.
Most of the systems we are finding have Base Ray emitters or fin tube with zone valves. Coming from more of a commercial/DDC background I want to automate the process, but need to make it cost effective for the homeowner. 
With space limitations on the past few jobs repiping to more primary/secondary piping was not viable option. The Danfoss ESBE appears to be a cost effective option for boiler return protection.
Anyone have experience with these? Pros/Cons? 
Other similar products to investigate? 

NoelAnderson

On the last job I did, I used a rebadged Burnham boiler. Burnham has a System by-pass kit [part number 107795-01] as seen on page 42 on the following instructions:

https://www.ecomfort.com/manuals/deac2e0430b5098f7dbe2f1589079fa7.pdf

The kit can be bought from:

https://www.supplyhouse.com/Burnham-107795-01-Boiler-Bypass-Kit

Even though it is a Burnham kit, it could be retrofitted to other brand of boilers. I also used a Hydrostat with condensation protection turned on. I found it was cheaper to buy Burnham's System by-pass kit than buy Taco's pump by itself.

offdutytech

That could be an option for some installs. The last few space has not been my friend for pipe layout.

STEVEusaPA

That valve is a fine way to protect the boiler and has been used for many decades.

hot_rod

If you if you want 100% boiler return protection the valve needs to be able to sense return temperature and react. The 3 way thermostatic valves are accurate, easy to pipe, high cv options. Use the type specific for return protection, the off the shelf thermostatic 1017 valves are too restrictive 

EricPeterson

hot_rod said:

If you if you want 100% boiler return protection the valve needs to be able to sense return temperature and react. The 3 way thermostatic valves are accurate, easy to pipe, high cv options. Use the type specific for return protection, the off the shelf thermostatic 1017 valves are too restrictive 

@hot_rod - can the Calfee valve be piped without a second circulator? Is it better than the ESBE valve?
This is for a converted gravity system with a non-condensing boiler.

offdutytech

Thanks for the feedback. I like like the simplicity for the homeowner. The price point on those is a good value vs a high priced automated mixing valve. Not everyone has a Cadillac budget for system change outs.

EricPeterson

I have a converted gravity system with a non-condensing boiler and for years I've been looking for a better solution than what I'm using now (ball valve half open serving as a system bypass). Diagram below.
System consists of three zones, two zones are from the converted gravity system - big radiators and lots of water.
On the one hand my system bypass is working fine so "if it ain't broke don't fix it".
On the other hand I would like something more precise.
SupplyHouse sells both the Danfoss (ESBE) and Caleffi valves (as well as the Burnham kit) but for these valves there are diagrams showing both one and two circulators.
I would like to just add the valve without adding a second circulator. I called Danfoss about this but they were unable to give me a clear answer. So I am reaching out the to the Wall.
Danfoss diagrams below.
If I have to add a second circulator then the Burnham kit seems better to me. Thoughts?
Thanks for any help you can give me!

Matt_67

I like the esbe with primary/secondary for cast iron radiators. With a heat loss sized boiler on startup the boiler jumps up to 140 and then the system slowly and evenly comes up to temperature. When using a single circulator you can have really low flows into the system and I had a project where that led to uneven heating.

EricPeterson

If I have to add a pump for the thermal valves anyway, the Burnham kit looks to be the simplest solution as it's a pump and a sensor. That beats a pump and a valve, and the Burnham kit would be a drop-in replacement for the ball valve I have currently have.


It says the the kit comes with fittings. SupplyHouse does not indicate the size but it looks like 1-1/4" to me:


Such a simple solution, it makes me wonder why this is not simply included inside every non-condensing boiler. It would make installation of these boilers so much more straightforward IMO.
It also makes me wonder why Burnham does not reference this kit in their own boiler documentation. It was not to be seen anywhere in what I received for the ES-27.

NoelAnderson

The fittings are 1-1/4". Burnham doe have it in their instructions for the X-202 boilers. The sensor comes with the Taco circulator 007-VSF5-4IFC

hot_rod

I think that variable speed bypass set up needs a system pump?
The circ in that kit just attempts to keep the boiler return above 120F

I think for it to provide protection, the system circulator would need to stop?

EricPeterson

@NoelAnderson - better late than never.
@hot_rod - Yes a system pump is still needed - IMO - the diagram is incomplete. I don't think the system pump would need to stop though, the VS pump would steal water from the system loop until the return temperature level was met.

STEVEusaPA

I’d use the Caleffi thermoblock before I’d use that bypass set up.
https://d3501hjdis3g5w.cloudfront.net/images/products/zoom/281175a-1.jpg

hot_rod

With the 3 way 280 I mentioned or the block that @STEVEusaPA shows above, the pump in the block or the 1 pump you select may be adequate. You need to know how many gpm you require and the pressure drop of the system. That 280 is a 14 cv valve, so 1 psi drop at 14 gpm flow, plenty of pump capacity available

hot_rod

Here is a bit more of the v/s concept for boiler protection

Matt_67

The idronics document hot rod referenced is spot-on. I did a bypass with a VT2218 pump on a gravity radiator system several years ago and got in trouble with it. Not the pumps fault but I was pumping away and piped the bypass pump coming right out of the boiler to the return. When the bypass pump went to full speed the boiler delta T dropped and it did very little to raise the return temperature. I ended up repiping it so the bypass water was taken off after the system pump and that made it a lot better.

Matt_67

I meant to attach this with the last post.

EricPeterson

@hot_rod - thank you for the information! The full article is here - idronics-7
If the system return flow was at say 90F and the bypass @ 160F, and if the flows mixed equally (50% from each) then I would expect the boiler return temperature to be 125F. The article suggests though that this is not the case, that instead the flow from the system circulator overwhelms the bypass circulator and thus drives the return temperature way down. If this is correct, this would mean that Burnham is selling a Bypass kit that does not work.
I find it hard to believe the conclusion of the article 100%. I would think it would depend a lot on the particulars of the setup: namely the two pumps and the characteristics of the system.
In my current setup I don't even have a bypass circulator - only a half opened ball valve (diagram above). The circulator is a B&G NRF-22, and the system consists of three zones (WR zone valves):

• First floor FR: 33' of 9" CI baseboard with 1" pipe off the boiler
  
• First floor+basement: 3 free-standing radiators plus 14' of 9" CI baseboard, 2" pipe off the boiler
  
• Second/third floor: 6 free-standing radiators plus 34' of 7" CI baseboard, 2" pipe off the boiler
  

There are two ways to analyze my current setup. I can try and do it on paper but I would need to go back to school to figure it out. Or I can take some measurements in terms of supply / return water temperatures as I have gauges for both. And a IR thermometer.

Going forward - I would like to upgrade my system with a thermal valve, either Danfoss or Caleffi.
As @Matt_67 suggested, there may be flow issues with a single circulator.
I would prefer a single circulator to keep things simpler. Perhaps the NRF-22 will work well enough, or as @STEVEusaPA suggested use the Caleffi 281 ThermoBloc™ Recirculation and Distribution Unit (NPT) which includes a circulator.
But if I need two circulators to provide reliable heat that is OK too.
So how to proceed?
The approach could be done by trial and error (NOT my favorite method) or trying to figure it out on paper ahead of time. So I guess I have some more homework to do before the next heating season.

Thanks @STEVEusaPA, @Matt_67, @hot_rod, @offdutytech, @Noel for responding to my post so far!

Eric

hot_rod

My thought is that a drawing or “module” for return protection should work in all and any case. Isn’t that the intent and also what it is being sold to provide?  The buyer or installer should not be required to run calculations, even if they know how 😉 to assure the method or device works as advertised?    

There is a super simple way to use a v/s temperature responding circulator to accomplish 100% return protection

Just taking off, I’ll attach a correct drawing later today. Anyone want to post a drawing of a workable solution?

EricPeterson

Matt_67 said:

The idronics document hot rod referenced is spot-on. I did a bypass with a VT2218 pump on a gravity radiator system several years ago and got in trouble with it. Not the pumps fault but I was pumping away and piped the bypass pump coming right out of the boiler to the return. When the bypass pump went to full speed the boiler delta T dropped and it did very little to raise the return temperature. I ended up repiping it so the bypass water was taken off after the system pump and that made it a lot better.

@Matt_67 - my bypass is after the system pump (and I'm pumping away). I was unable to open that JPG file you posted.

@hot_rod - I am all for "plug and play" modules. I prefer simple solutions, especially if the complexity is contained with the module.
Years ago I considered purchasing the Burnham "Revolution" boiler, because it had an internal circulator which supposedly addressed issues of condensation and thermal shock. But I decided against it, because the venting required special kind of pipe, and looked really complicated. In fact the first 46 pages of the installation manual were used for venting and air intake. Good thing I guess since it was discontinued in 2012.

hot_rod

In the rural areas of Europe, pellet and wood fired boilers are still common. The Caleffi 280 valve is sold into that market, thousands of them. These drawings all show a buffer tank as that is fairly important on zoned systems with a solid fueled boiler that needs to run hot to be clean running. it also give you some flywheel. So these application drawings show the piping where a buffer is included.

But any large piped system like a converted gravity with cast radiators would be a similar high mass, high water content load. Zoning a fixed output cast boiler can cause short and cold cycles also, return protection valves protect in that case, also. Notice that cast boilers are shrinking, behaving more like low water content copper tube boilers, which tended to short cycle their brains out, but could handle low return temperatures better.

With this valve you can select whichever circulator the application requires. A low pressure drop boiler, like a cast sectional does not present a lot of pressure drop, so a single circulator can cover the boiler, bypass requirement, and the distribution.

If for example you have small diameter tube radiant, a buffer or hydraulic separator, and a separate circ would assure all circuits get adequate flow and a properly sized circulator.

So it does take some knowingness or calculating to assure you have bases covered, and every system is different, hard to "cookie cutter" a solution.

hot_rod

EricPeterson said:

@hot_rod - thank you for the information! The full article is here - idronics-7
If the system return flow was at say 90F and the bypass @ 160F, and if the flows mixed equally (50% from each) then I would expect the boiler return temperature to be 125F. The article suggests though that this is not the case, that instead the flow from the system circulator overwhelms the bypass circulator and thus drives the return temperature way down. If this is correct, this would mean that Burnham is selling a Bypass kit that does not work.
I find it hard to believe the conclusion of the article 100%. I would think it would depend a lot on the particulars of the setup: namely the two pumps and the characteristics of the system.
In my current setup I don't even have a bypass circulator - only a half opened ball valve (diagram above). The circulator is a B&G NRF-22, and the system consists of three zones (WR zone valves):

• First floor FR: 33' of 9" CI baseboard with 1" pipe off the boiler
  
• First floor+basement: 3 free-standing radiators plus 14' of 9" CI baseboard, 2" pipe off the boiler
  
• Second/third floor: 6 free-standing radiators plus 34' of 7" CI baseboard, 2" pipe off the boiler
  

There are two ways to analyze my current setup. I can try and do it on paper but I would need to go back to school to figure it out. Or I can take some measurements in terms of supply / return water temperatures as I have gauges for both. And a IR thermometer.

Going forward - I would like to upgrade my system with a thermal valve, either Danfoss or Caleffi.
As @Matt_67 suggested, there may be flow issues with a single circulator.
I would prefer a single circulator to keep things simpler. Perhaps the NRF-22 will work well enough, or as @STEVEusaPA suggested use the Caleffi 281 ThermoBloc™ Recirculation and Distribution Unit (NPT) which includes a circulator.
But if I need two circulators to provide reliable heat that is OK too.
So how to proceed?
The approach could be done by trial and error (NOT my favorite method) or trying to figure it out on paper ahead of time. So I guess I have some more homework to do before the next heating season.

Thanks @STEVEusaPA, @Matt_67, @hot_rod, @offdutytech, @Noel for responding to my post so far!

Eric

Here is an example of where a V/S temperature circulator does provide absolute protection. it has the ability to disconnect the load from the source, or boiler. Same two circs as that module shows, but better placed to do the job. It allows the "smart" circulator to use its education

On a converted gravity system I think the V/S circ would provide enough circulation. Still a two pump solution, but one that is thermodynamically sound.

EricPeterson

hot_rod said:

In the rural areas of Europe, pellet and wood fired boilers are still common. The Caleffi 280 valve is sold into that market, thousands of them. These drawings all show a buffer tank as that is fairly important on zoned systems with a solid fueled boiler that needs to run hot to be clean running. it also give you some flywheel. So these application drawings show the piping where a buffer is included.

But any large piped system like a converted gravity with cast radiators would be a similar high mass, high water content load. Zoning a fixed output cast boiler can cause short and cold cycles also, return protection valves protect in that case, also. Notice that cast boilers are shrinking, behaving more like low water content copper tube boilers, which tended to short cycle their brains out, but could handle low return temperatures better.

With this valve you can select whichever circulator the application requires. A low pressure drop boiler, like a cast sectional does not present a lot of pressure drop, so a single circulator can cover the boiler, bypass requirement, and the distribution.

If for example you have small diameter tube radiant, a buffer or hydraulic separator, and a separate circ would assure all circuits get adequate flow and a properly sized circulator.

So it does take some knowingness or calculating to assure you have bases covered, and every system is different, hard to "cookie cutter" a solution.

@hot_rod - thank you for the breakdown. Based on your comments I will now plan on using a Caleffi valve with my current NRF-22 circulator. If I run into flow issue I can add a second circulator.

hot_rod said:

On a converted gravity system I think the V/S circ would provide enough circulation. Still a two pump solution, but one that is thermodynamically sound.

@hot_rod - this looks similar to the Burnham kit but with the pumps reversed: a variable speed for the main circuit and and fixed speed for the boiler loop.

hot_rod

@hot_rod - this looks similar to the Burnham kit but with the pumps reversed: a variable speed for the main circuit and and fixed speed for the boiler loop

Exactly:) It's just a matter of understanding how to build a thermal clutch. A means to temporarily disconnect the load from the boiler or heat source.

3 options that work,
the one just mentioned with the VS pump in the correct location
A 3 way thermostatic properly sized and installed
A bang/ bang aquastat that turns off the system pump when temperature drops at the boiler.

EricPeterson

hot_rod said:

@hot_rod - this looks similar to the Burnham kit but with the pumps reversed: a variable speed for the main circuit and and fixed speed for the boiler loop

Exactly:) It's just a matter of understanding how to build a thermal clutch. A means to temporarily disconnect the load from the boiler or heat source.

3 options that work,
the one just mentioned with the VS pump in the correct location
A 3 way thermostatic properly sized and installed
A bang/ bang aquastat that turns off the system pump when temperature drops at the boiler.

@hot_rod - your third option made me recall the original boiler installation in my house which had an aquastat strapped onto the supply line, so the pump would only run when the output water temperature reached a certain level. I suppose that provided some protection.

The second option is what I now want to pursue. My two considerations are:

1. Which valve?
   • ESBE Series 1-1/4" 3-Way Thermic Valve
     
   • Caleffi 1-1/4" Male NPT ThermoMix Thermostatic Mixing Valve
     
2. Would one circulator suffice or would I need two?
   

The ESBE has three options: 122°F, 131°F, 140°F; the Caleffi has two options: 130°F, 140°F.
Since the stated acceptable return temperature for my boiler is 110°F any of these would work. The Caleffi appears to be of better construction (brass).

As for the pumping if I use a single circulator it's pretty straightforward. The consideration there though is would I get in a situation where as @Matt_67 indicated: "...using a single circulator you can have really low flows into the system and I had a project where that led to uneven heating".
If I understand the valve operation, it does not simply open and close- instead it starts to open at a certain temperature, and is fully open only when the water gets sufficiently hot. So essentially it is providing a mixing function between 0% (fully closed) and 100% (fully open) over a temperature range.
If that is the case than I don't see why I would have any system flow problems, given that with my current setup (ball valve half-open) the flow would be the same as when the thermostatic valve is 50% open. I don't have any flow issues with this setup. My concern is doing a better job of preventing thermal shock and condensation for my non-condensing boiler.
Questions concerning these valves:

• what is the expected lifetime of the thermostatic element? (those in cars seem to last the lifetime of the car)
  
• how reliable is the valve - could it fail by getting stuck open, closed, or somewhere in between?
  

If it did turn out that I needed two circulators then that leads back to additional considerations:

• how would these need to be piped?
  
• which circulator to use for boiler and system loops, and how would these be controlled?
  

One other "Cadillac" option would be that really cool Caleffi all-in-one product: 1-1/4" NPT ThermoBloc Recirculation and Distribution Unit (130°F)

offdutytech

Thanks for the responses to this. It has sparked some great conversations and new ideas! It's great to have options. 

hot_rod

EricPeterson said:

hot_rod said:

@hot_rod - this looks similar to the Burnham kit but with the pumps reversed: a variable speed for the main circuit and and fixed speed for the boiler loop

Exactly:) It's just a matter of understanding how to build a thermal clutch. A means to temporarily disconnect the load from the boiler or heat source.

3 options that work,
the one just mentioned with the VS pump in the correct location
A 3 way thermostatic properly sized and installed
A bang/ bang aquastat that turns off the system pump when temperature drops at the boiler.

@hot_rod - your third option made me recall the original boiler installation in my house which had an aquastat strapped onto the supply line, so the pump would only run when the output water temperature reached a certain level. I suppose that provided some protection.

The second option is what I now want to pursue. My two considerations are:

1. Which valve?
   • ESBE Series 1-1/4" 3-Way Thermic Valve
     
   • Caleffi 1-1/4" Male NPT ThermoMix Thermostatic Mixing Valve
     
2. Would one circulator suffice or would I need two?
   

The ESBE has three options: 122°F, 131°F, 140°F; the Caleffi has two options: 130°F, 140°F.
Since the stated acceptable return temperature for my boiler is 110°F any of these would work. The Caleffi appears to be of better construction (brass).

As for the pumping if I use a single circulator it's pretty straightforward. The consideration there though is would I get in a situation where as @Matt_67 indicated: "...using a single circulator you can have really low flows into the system and I had a project where that led to uneven heating".
If I understand the valve operation, it does not simply open and close- instead it starts to open at a certain temperature, and is fully open only when the water gets sufficiently hot. So essentially it is providing a mixing function between 0% (fully closed) and 100% (fully open) over a temperature range.
If that is the case then I don't see why I would have any system flow problems, given that with my current setup (ball valve half-open) the flow would be the same as when the thermostatic valve is 50% open. I don't have any flow issues with this setup. My concern is doing a better job of preventing thermal shock and condensation for my non-condensing boiler.
Questions concerning these valves:

• what is the expected lifetime of the thermostatic element? (those in cars seem to last the lifetime of the car)
  
• how reliable is the valve - could it fail by getting stuck open, closed, or somewhere in between?
  

If it did turn out that I needed two circulators then that leads back to additional considerations:

• how would these need to be piped?
  
• which circulator to use for boiler and system loops, and how would these be controlled?
  

One other "Cadillac" option would be that really cool Caleffi all-in-one product: 1-1/4" NPT ThermoBloc Recirculation and Distribution Unit (130°F)

There are 4 options for the Caleffi 280 temperatures, 115, 130, 140, 160. keep in mind the 18° differential. I ended up with a 115° on my wood fired boiler,
So, completely closed at 115 + 18= 133°. With the original 140, the boiler was ramping down before my buffer tank reached 180F.

Rarely, but occasionally a heat motor fails, it is a copper capsule filled with wax and powdered copper. The system fluid needs to be clean so debris doesn't stick the cartridge from moving freely.
The simplicity of the valve, a cartridge, spring and copper "heat motor"
Use a magnetic dirt separator, for sure, good water, and some Rhomar conditioner.

Either brand will work fine. The Caleffi is brass, union connection with temperature gauge wells. Easily removed from the piping if you do need to flush out some debris.

I prefer the 280 so you can select the pump of your choice, an ECM style circulator would give you more options and use less energy. With the 281 you are tied to that Wilo, should it ever fail it could not be substituted with another brand.

As for pump control, probably fire both if you do end up needing two, with a heat call.

If you use constant circulation, obviously a system pump could run constantly.

On my shop I chose to run constant circulation instead of glycol for freeze protection. Simply use a 3 way zone valve. The Ecobee thermostat energizes the zone valve and triggers the boiler call for heat via the end switch. I have a Grundfos Alpha on speed 3, running 37W

Constant circulation provides a very comfortable, even floor temperature.
And it moves any passive solar gain on sunny days from my south facing windows, into the slab for just the cost of running that 37W ECM circulator.