This is almost unreal , I ordered parts yesterday and came home last night to a cold house ! Seems the termovar is stuck open now and failed to close off my return so my zones were pumping thru my boiler to the house and back , Storage was nearly full . Will take a few pictures when we do the rebuild after the parts get here and see what we find .
Getting the most from Big BTU's Termovar , Danfoss , Loading unit ?
- Thread starter webie
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
- Status
Disassembled the termovar yesterday , I found the problem on why it wasnt closing and that was a small balled up teflon tape was stuck in between . I had gotten a new element but wanted to check the old element first and it seems to have been working fine . I also tested the new element in the same pan of boiling water and both movements to my eyes seemed the same . After taking this thing apart it makes more sense on how this thing can actually work but I am unsure why the engineers felt it necessary to not build a valve that closed up the supply side rather than leaving it wide open and user controlled by the balancing valve .
Seeing I had the new element I put that in . I can say this , my termovar has never ever worked like this in the 12 years it has been running . To my ears this thing is quiet now my old element was noisy . The first burn I did I had to open my balancing valve a lot in order to keep my boiler return at right around 140 , I am scratching my head on why this is ? Its like this element is opening at a lower temperature or something compared to my old element and they both should have been that 72 c My flow seems to have increased a fair amount because I was able to only have one idle period about an hour into my first burn .
I will have to try this a bunch of burn sessions but the first burn proved to be a lot better than I have ever been able to achieve so far to date .
Seeing I had the new element I put that in . I can say this , my termovar has never ever worked like this in the 12 years it has been running . To my ears this thing is quiet now my old element was noisy . The first burn I did I had to open my balancing valve a lot in order to keep my boiler return at right around 140 , I am scratching my head on why this is ? Its like this element is opening at a lower temperature or something compared to my old element and they both should have been that 72 c My flow seems to have increased a fair amount because I was able to only have one idle period about an hour into my first burn .
I will have to try this a bunch of burn sessions but the first burn proved to be a lot better than I have ever been able to achieve so far to date .
Armaton
Member
Web,
Congrats! Don't you hate it when the fix is so simple, you wonder why you didn't try it before? I still wonder, as you do, why the early thermostatic valves seem to need a valve in line before them to "Optimize" their use. Keep the updates coming.
Congrats! Don't you hate it when the fix is so simple, you wonder why you didn't try it before? I still wonder, as you do, why the early thermostatic valves seem to need a valve in line before them to "Optimize" their use. Keep the updates coming.
Danfoss VTC is ordered , along with a 140 degree element . Freind of mine will help me plumb it in ,in the next few weeks .
[/ATTACH]
View attachment 128279 Well the new danfoss VTC510 valve has arrived . The old termovar was being its typical child and I have reset it three times trying to compensate for return temps today as I was heating up my sunroom floor from 44 degrees to 92 degrees . It is working lots better than it has ever worked since I replaced the element and I can stay in the burn sometimes quite long before it idles . I decided last minute here and have just ordered a Y strainer for to place in line prior to the valve in hopes we dont have any debris problems like I incurred with the termovar . I took a couple of pictures of the old valve in place . The solo 60 is the second wood boiler in my set up and was not pretty to install because of cramped plumbing so this should be another real joy .
Hopefully we are installing it next weekend pending parts and weather .
View attachment 128279 Well the new danfoss VTC510 valve has arrived . The old termovar was being its typical child and I have reset it three times trying to compensate for return temps today as I was heating up my sunroom floor from 44 degrees to 92 degrees . It is working lots better than it has ever worked since I replaced the element and I can stay in the burn sometimes quite long before it idles . I decided last minute here and have just ordered a Y strainer for to place in line prior to the valve in hopes we dont have any debris problems like I incurred with the termovar . I took a couple of pictures of the old valve in place . The solo 60 is the second wood boiler in my set up and was not pretty to install because of cramped plumbing so this should be another real joy .Hopefully we are installing it next weekend pending parts and weather .
Attachments
jebatty
Minister of Fire
Addressing the issue of a big BTU boiler idling and loading unit. I have addressed this issue with regard to the Froling FHG L50 (170,000 btuh), and you may find some helpful info in reviewing this: https://www.hearth.com/talk/threads/froling-fhg-l-50-install.73268/
The "simple" fix in my case was two-fold:
1) replumbing to provide that the boiler charge the tank directly (boiler supply to top of tank, boiler return from bottom of tank) and for the system to draw from the tank directly (top of tank to system, system return to middle of tank). The boiler never supplies the system directly, and the system never returns warm water to the boiler directly. In the DP situation this resulted in assuring that the coldest water from the bottom of tank always was being returned to the boiler via the loading unit, which also resulted in a delta-T of 30F or greater.
2) tuning the flows in the zones on the system to result in a difference between system supply/return of at least 20F. Before the tuning, this temp difference at times was as little as 10F.
A middle of tank sensor is the guide point for determining boiler firing. Based on the 1600 gallon tank, if at least a temp difference of 30F between middle and bottom of tank and assuming average system draw during the burn cycle, the boiler can take a full wood load and burn to completion without idling. Because non-technical staff frequently fires the boiler, and to insure virtually no idling possibility, the actual staff guide point is 50F.
This works in DP's case in part because the tank is large enough and the plumbing arrangement (return of warm system water to middle of tank) insure little or no mixing of the return water into the bottom half of the tank, therefore always keeping the coldest water available for boiler return. It also works because the tank is of a size that provides both reasonable storage capacity and buffer capacity. The Froling manual properly advises not to fire the boiler if there isn't sufficient thermal storage (buffer) available to take the btu output.
There are complications depending on particular system designs that may make it more or less difficult to solve the issue. But a basic fact is that the the LK810 is spec'd at maximum flow of about 12 gpm, System design may result in lesser flow. And at 12 gpm, the maximum btu's that can be moved are limited: 120,000 at delta-T=20F; 180,000 at 30F, etc. If this output cannot be accepted by the storage/system, idling will result. Some solutions, therefore, are as described above which worked, and may also include, among others:
1) taking care in firing the boiler to insure that the wood load is well burned down as delta-T closes, therefore btu output is substantially less than than maximum, and flow of 12 gpm moves all btu output.
2) limiting wood loads in the boiler, and in this regard weighed wood burns can be quite helpful
3) not attempting to charge storage to a high temp point without care to insure that the boiler is not over loaded, and again, weighed wood burns can be quite helpful
4) adding a parallel circulator to the LK810 which cuts in only at high temperature to increase flow, thereby increasing btu capacity (still need system demand/storage to accept the btu's)
A person might conclude, as I did at one time, that the LK810 is undersized for a large btu output boiler. But I think the issue is more related to system design, demand characteristics of the system, insufficient buffer/storage capacity, over sizing the boiler for the system, over loading the boiler based on system design and/or demand, failure to appreciate or understand boiler btu output as related to size of wood load, or boiler output as related to stage of the burn.
With the changes made in the DP system, I now feel the LK810 is satisfactorily sized for large btu output boilers, but that the system needs to be designed accordingly. System design is not necessarily easy or simple, there are many variables, only one of which is the LK810, and it is necessary to understand how the entire system will operate, whether or not the LK810 is part of the system.
The "simple" fix in my case was two-fold:
1) replumbing to provide that the boiler charge the tank directly (boiler supply to top of tank, boiler return from bottom of tank) and for the system to draw from the tank directly (top of tank to system, system return to middle of tank). The boiler never supplies the system directly, and the system never returns warm water to the boiler directly. In the DP situation this resulted in assuring that the coldest water from the bottom of tank always was being returned to the boiler via the loading unit, which also resulted in a delta-T of 30F or greater.
2) tuning the flows in the zones on the system to result in a difference between system supply/return of at least 20F. Before the tuning, this temp difference at times was as little as 10F.
A middle of tank sensor is the guide point for determining boiler firing. Based on the 1600 gallon tank, if at least a temp difference of 30F between middle and bottom of tank and assuming average system draw during the burn cycle, the boiler can take a full wood load and burn to completion without idling. Because non-technical staff frequently fires the boiler, and to insure virtually no idling possibility, the actual staff guide point is 50F.
This works in DP's case in part because the tank is large enough and the plumbing arrangement (return of warm system water to middle of tank) insure little or no mixing of the return water into the bottom half of the tank, therefore always keeping the coldest water available for boiler return. It also works because the tank is of a size that provides both reasonable storage capacity and buffer capacity. The Froling manual properly advises not to fire the boiler if there isn't sufficient thermal storage (buffer) available to take the btu output.
There are complications depending on particular system designs that may make it more or less difficult to solve the issue. But a basic fact is that the the LK810 is spec'd at maximum flow of about 12 gpm, System design may result in lesser flow. And at 12 gpm, the maximum btu's that can be moved are limited: 120,000 at delta-T=20F; 180,000 at 30F, etc. If this output cannot be accepted by the storage/system, idling will result. Some solutions, therefore, are as described above which worked, and may also include, among others:
1) taking care in firing the boiler to insure that the wood load is well burned down as delta-T closes, therefore btu output is substantially less than than maximum, and flow of 12 gpm moves all btu output.
2) limiting wood loads in the boiler, and in this regard weighed wood burns can be quite helpful
3) not attempting to charge storage to a high temp point without care to insure that the boiler is not over loaded, and again, weighed wood burns can be quite helpful
4) adding a parallel circulator to the LK810 which cuts in only at high temperature to increase flow, thereby increasing btu capacity (still need system demand/storage to accept the btu's)
A person might conclude, as I did at one time, that the LK810 is undersized for a large btu output boiler. But I think the issue is more related to system design, demand characteristics of the system, insufficient buffer/storage capacity, over sizing the boiler for the system, over loading the boiler based on system design and/or demand, failure to appreciate or understand boiler btu output as related to size of wood load, or boiler output as related to stage of the burn.
With the changes made in the DP system, I now feel the LK810 is satisfactorily sized for large btu output boilers, but that the system needs to be designed accordingly. System design is not necessarily easy or simple, there are many variables, only one of which is the LK810, and it is necessary to understand how the entire system will operate, whether or not the LK810 is part of the system.
Last edited:
Thanks Jebatty for th response . I am not sure that I could replumb and pull from the top of my storage and return to the bottom unless I would have a complete seperate heat exchanger . I use the same 3-180ft coils to heat and reclaim from the unpressurized storage that I have . I also dont think its possible as in the set up at DP to return water to the middle of my storage again its the unpressurized storage thing , This is where some of the issues are and why the Guys at Tarm dont think a LK810 will work because the pump is just not big enough to handle the BTU output of the solo 60 because the pump cant maintain the 12 GPM thru the exchanger coils . I can get the solo 60 to stay in the burn as long as I keep throttling down the balancing valve as the over all return rises . As long as I can stay between 140 and 150 on my boiler return it stays out of idle but I am also runing a pump equal to a 26-99 grundfos to do it . I am going to try installing the Danfoss , it looks like it should work like a loading valve where as the termovar is strickly a tempering valve .
I am very tight on space and I hope this works because as I have it planned right now my main return is going to elboe into the strainer to the danfoss then elboe to the pump then elboe to the boiler return and into the boiler about 6 inches away .
I am waiting on one fitting and the isolation flanges to show up today .
I am very tight on space and I hope this works because as I have it planned right now my main return is going to elboe into the strainer to the danfoss then elboe to the pump then elboe to the boiler return and into the boiler about 6 inches away .
I am waiting on one fitting and the isolation flanges to show up today .
- Status
Similar threads
