Topping off the tank

[chuck172]

Woodnotoil, Yes you should put it in the smokebox, you have storage. There is a small horizontal hole, below the access plate on the right side,(facing the boiler). The long probe gets inserted in there.
Set the low limit to 190*F

 

[chuck172]

I wired a 110vac relay to the low limit switch. To the relay I wired the circ. pump in series. I'm gonna see if I can use the low limit switch to turn off the pump when the fire dies down. It would save buying a differential control.
A problem with this might be if the boiler goes into idle, will the firebox cool and keep the pump off?

 

[WoodNotOil]

Any particular position in there or does it just dangle?

If you have a 110vac tester light you could hook it up to your relay first and watch what it does throughout different parts of a burn cycle. That should answer you question about idling. Let me know how it turns out. If it works it might save a bunch of us from buying more expensive controls.

 

[DenaliChuck]

I've got to say it is great to be able to learn from everybody here!

 

[DaveBP]

Yes you should put it in the smokebox, you have storage. There is a small horizontal hole, below the access plate on the right side,(facing the boiler). The long probe gets inserted in there.
Set the low limit to 190*F

I also have a Tarm Solo 40 but I'll be blessed if I can find in the manual where it says to put the low limit sensor in the smoke box. It just says if you have storage you'll have to mount it differently. Thanks, Chuck172. I'm not going to get mine running probably until I don't need it in the spring, but boy am I following this forum and taking notes.

 

[2.beans]

i installed 24 volt fast acting zone valves on tank supply line and and one on a cross over/bypass return line. used a sensor in the tank so when the tank hits my desired temp lets say 175* the controller shuts the supply and opens the bypass which returns the water back to the boiler also it shuts off the power to the draft door and wont let it open until the tank drops to my desired differential. this stops the tank water from mixing. also these valves act like check valve and stop the thermosyphoing . also if the wood boiler starts to creap up in temp the valves open and act as a dump zone sending some cold water from the bottom of the tank to the boiler to cool it down. ive set up three seton boilers like this and seems to be working good so far. now i need to minimize the the circulation on the house side supply and return (next project). heres some pics of my father inlaws valves supply and return tank temp gauges and controller.

 

[chuck172]

DaveBP-On page 28 of the Alternate Instructions that came with the Tarm Manual:
Insert the longest sensor probe in the sensor well that is on the right hand front side of the smoke box.

 

[mpilihp]

Hi 2.beans, what is the controller your using to turn your valves open/closed to storage? Can you post a diagram and wiring of your setup??

Thanks

~ Phil

 

[oilbegone]

In the picture I have the probe in the hole in the front of the smoke box you just can't see it because the insulation is in the way. The coil resting on the wing nut just helps keep the probe in the place. My installer made the same mistake about the low limit dial not reading in Fahrenheit thanks to this forum and all the great information I was able to figure out what the problem was.

 

[jebatty]

Tarm low limit sensor: we must have different instructions depending on our boiler design. On pg 28 of the instruction manual for my Tarm 40 the following is stated:

"Place the longest probe under the insulation on top of the boiler. This long probe controls the fan low limit which should be set at 60 degrees C. The placement and setting of this probe will be different if you have a heat storage system."

I changed the low limit setting to 90C as I have storage.

No mention is made of putting the probe in the smoke box.

 

[2.beans]

Hi 2.beans, what is the controller your using to turn your valves open/closed to storage? Can you post a diagram and wiring of your setup??

Thanks

~ Phil

i use a ranco etc controller.the wiring is pretty simple, the picture attached shows the load contacts at the bottom of the controller there is a NO C NC. you put 24 volt input to C then NC goes to the supply zone valve and NO goes to the bypass zone valve.i didnt take it apart to check this but its easy to set up with a volt meter. you get your supply voltage from a 24 volt transformer and run the red wire to the ranco controller from the ranco controller to the zone valve and the white to the zone valve for the neutral. the ranco in the picture is a dual stage 211000-000. all you need to bypass a tank is a single stage 24 volt model 112000-000.{ it shows in the picture 120 volt on the upper part of the controller but on a 24 volt one its 24 volt.} i hope i didnt make something easy seem confusing.

 

[deerefanatic]

I will address the question asked earlier as to how cool you can run your tank water........

I can keep the house warm down to about 135F water temps. Beyond that, the furnace runs alot and not much heat comes out.. PLus, at night, I probably couldn't get away with less than 145F water.......

I too have a 20x20 air coil in my furnace.....

 

[free75degrees]

Tarm low limit sensor: we must have different instructions depending on our boiler design. On pg 28 of the instruction manual for my Tarm 40 the following is stated:

"Place the longest probe under the insulation on top of the boiler. This long probe controls the fan low limit which should be set at 60 degrees C. The placement and setting of this probe will be different if you have a heat storage system."

I changed the low limit setting to 90C as I have storage.

No mention is made of putting the probe in the smoke box.

When I got my manual they gave me a few extra pages of "alternate" instructions because they knew I would be installing a tank. One of the pages was page 28 with the difference on where to put the probe. If they didn't think you were installing a tank they might not have given you the alternative pages. Or maybe the alternates are a newer thing they are giving out.

However, I never figured out the alternate location for that probe so i just put it under the insulation. Why is it better for it to be in the smokebox when you have a tank?

 

[chuck172]

Tarm low limit sensor: we must have different instructions depending on our boiler design. On pg 28 of the instruction manual for my Tarm 40 the following is stated:

"Place the longest probe under the insulation on top of the boiler. This long probe controls the fan low limit which should be set at 60 degrees C. The placement and setting of this probe will be different if you have a heat storage system."

I changed the low limit setting to 90C as I have storage.

No mention is made of putting the probe in the smoke box.

Jebatty, Check #8

 

[rickh1001]

I'm kind of late to the party on this thread, but it is an interesting one. For those of us with EKO's and the RK-2001UA controllers (and perhaps the other models as well), the minimum temp for the circulator on can be adjusted. The factory default is P144 (on at 144 deg F). However, I set mine to the maximum of P160. So if the boiler drops below 160F, the boiler circ will be off, letting me use the storage tank down to about 140F or so with the plenum heat exchangers I am using. I also have had no problem charging my 500 gal pressurized tank to 175-180 deg, by setting the EKO target temp to 190F. So at least when I run out of fuel, the tank will retain the water at 160F without further losses to the EKO. Not a perfect solution to the basic problem, but at least it minimizes the impact in an easy way.

 

[mpilihp]

Hi 2.beans, what is the controller your using to turn your valves open/closed to storage? Can you post a diagram and wiring of your setup??

Thanks

~ Phil

i use a ranco etc controller.the wiring is pretty simple, the picture attached shows the load contacts at the bottom of the controller there is a NO C NC. you put 24 volt input to C then NC goes to the supply zone valve and NO goes to the bypass zone valve.i didnt take it apart to check this but its easy to set up with a volt meter. you get your supply voltage from a 24 volt transformer and run the red wire to the ranco controller from the ranco controller to the zone valve and the white to the zone valve for the neutral. the ranco in the picture is a dual stage 211000-000. all you need to bypass a tank is a single stage 24 volt model 112000-000.{ it shows in the picture 120 volt on the upper part of the controller but on a 24 volt one its 24 volt.} i hope i didnt make something easy seem confusing.

Hi 2beans thanks, I do better with pictues, here is a sketch of how you have your controller hooked up I think. Can you fill in the blanks for the controls of each zone valve, IE what contact type NO or NC each is connected to?? Im thinking both zone valves A and B are on a NO contact and C is on a NC contact correct?

Sensor is set at 175 deg on the tank?

I can see how this stops charging the tank when it reaches 175 degs, but how does it monitor the temp of the wood boiler and allow charging when the wood boiler temp is hotter than the tank, or if the wood boiler dies before the tank is fully charged, how does this shut off the tank and keep it from being charged with colder water??

http://i103.photobucket.com/albums/m132/mjenphil/WoodBoiler/Storagetankcontrol.jpg

~ Phil

 

[oilbegone]

Back to the original topic. . . I think this control by Azel http://www.azeltec.com/catalog.0.html.0.html#DST-777 is made to accomplish the same thing as the Tekmar 156. Thoughts? I think it is a little bit less expensive and it uses line voltage instead of needing a 24vac transformer like the Tekmar. It also displays the temp from both sensors, so no separate tank theremometer would be needed for a top of tank reading. It says it can be used for tank heating. Would it work as well as the Tekmar?

I didn't know controls existed for this application. This is exactly what I have been looking for. Does anyone know of any other brands for comparison?

Edit: The Azel DST-7772 is actually $155 making it just a few dollars more than the Tekmar 156 which is $150. However as I said above the Tekmar needs a 24vac transformer which would add to the cost. (unless you already have one in your setup)

Last night I heated the tank up to 173 and in the morning it was 160, the circulator had been running all night and dropped the temperature in the tank that much. The house temperature had risen from 67 to 70 just from the heat given off, the thermostat was set back to 62 for the night.
These two controllers look like good solutions to the problem and I will eventually get one of them. The wife wants a humidifier first but that is another topic. My electrician installed a separate on off switch for the wood boiler circulator. If I am home when the fire dies out it can be switched off. My question is will it cause a problem if I build the next fire without turning it back on?

 

[2.beans]

Hi 2.beans, what is the controller your using to turn your valves open/closed to storage? Can you post a diagram and wiring of your setup??

Thanks

~ Phil

i use a ranco etc controller.the wiring is pretty simple, the picture attached shows the load contacts at the bottom of the controller there is a NO C NC. you put 24 volt input to C then NC goes to the supply zone valve and NO goes to the bypass zone valve.i didnt take it apart to check this but its easy to set up with a volt meter. you get your supply voltage from a 24 volt transformer and run the red wire to the ranco controller from the ranco controller to the zone valve and the white to the zone valve for the neutral. the ranco in the picture is a dual stage 211000-000. all you need to bypass a tank is a single stage 24 volt model 112000-000.{ it shows in the picture 120 volt on the upper part of the controller but on a 24 volt one its 24 volt.} i hope i didnt make something easy seem confusing.

Hi 2beans thanks, I do better with pictues, here is a sketch of how you have your controller hooked up I think. Can you fill in the blanks for the controls of each zone valve, IE what contact type NO or NC each is connected to?? Im thinking both zone valves A and B are on a NO contact and C is on a NC contact correct?

Sensor is set at 175 deg on the tank?

I can see how this stops charging the tank when it reaches 175 degs, but how does it monitor the temp of the wood boiler and allow charging when the wood boiler temp is hotter than the tank, or if the wood boiler dies before the tank is fully charged, how does this shut off the tank and keep it from being charged with colder water??

http://i103.photobucket.com/albums/m132/mjenphil/WoodBoiler/Storagetankcontrol.jpg

~ Phil

ill send you a pm tomorrows , nice picture.

 

[2.beans]

i have minute before work, you only need two zone valves, the one on the boiler return you can gat rid of. if your boiler has a dump zone hooked to it you set the dump higher then your tank set point. you use the tank as your dump zone by hooking the dump zone control (24 volt) wire to the tank supply zone valve. so as long as your boiler is putting out higher temp then your tank set point it will still charge your tank and then isolate your tank if its colder.

 

[mpilihp]

Hi 2.beans thanks im still wondering if there is a simpler way.

In the simpliest pressurized storage setup by Nofo, couldnt there be a threeway valve at the fill point of the tank on top and it configured as a diverter valve set to only allow water at a min temp of say 170 deg (this value up for discussion) that way when the wood boiler sends water at a lower temp than we want to charge the storage with it will return to the wood boiler. IE tank gets charged to 170 or above and doesnt get sucked back down by the wood boiler running as it cools off.

Now there would need to be one-way flow check valves to only allow water into the top of the tank through the 3-way valve and there would need to be a bypass line that goes past the 3-way valve with a one-way check valve to only allow water to flow out from the top in this bypass line. This would be how it would draw hot water out of the top of the tank for heating.

Im sure the diff controllers are a better method to get the most heating out ofthe wood boiler but I like simplicity. 5-10 years from now I dont want to have to deal with dead electronics and have to try and figure them out again and be able to set it back up.....

~ Phil