Bi-metal damper questions

Bi-metal damper questions

PostBy: michaelanthony On: Wed Jan 08, 2014 5:08 pm

Hi all, hope everyone is warm. I am running a V.C. Vigilant ll in the living room with 'nut and loving it. The only head scratchin' this winter is about the bi-metal damper in the rearlower left corner of the stove. Regardless of where I set the damper it is always in the same position 20, 30, 45 minutes later even an hour or so later. The stove gets up to the temp based on where I set it and stays there...all is good, but the damper never waivers and I'm wondering if it even works :? If I want to run the stove at 700* or so I shake, knife the grates and load it up and she gets there but the damper is always at approx. 50% open and won't move. I tried taking the slack out of the chain and even adjusted it slightly tight to no avail. I'm not worried about over firing the stove because it will stay where I set the damper but am I loosing heat up the chimney because it is not self adjusting? I can't post pic's because the stove is only a couple inches away from the fireplace, and a pic' won't show it not moving :lol:
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: freetown fred On: Wed Jan 08, 2014 5:38 pm

ma, don't know what to tell ya about the bi-metallic except that if the spring is shot--????????????? It's ALWAYS half open--strange indeed--even after a nights sleep & you haven't touched anything, it's not closed or seems to have moved a bit--crap, if mine was constantly half open, I'd start a SAUNA club here in the house--any ash build up?? just shootin in the dark my young friend 1/2 hr or more is not much play room to activate the bi-metallic flap!--do you have a PIPE DAMPER on her?
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: Bi-metal damper questions

PostBy: michaelanthony On: Wed Jan 08, 2014 5:47 pm

[quote="freetown fred"]ma, don't know what to tell ya about the bi-metallic except that if the spring is shot--????????????? It's ALWAYS half open--strange indeed--even after a nights sleep & you haven't touched anything, it's not closed or seems to have moved a bit--crap, if mine was constantly half open, I'd start a SAUNA club here in the house--any ash build up?? just shootin in the dark my young friend--do you have a PIPE DAMPER on her?[/quote]

I installed a mpd for wood burnin', that's April in these parts. I suspect it is shot but no worries the stove is having a good winter and fortunately it is cast so it likes 700 plus and I have been laid off so you know I probably shake it more out of boredumB :funny: I think my average draft on the first floor is keeping things in check, if this was in the basement I would be worried because the extra 8 ft of chimney makes a big difference draft wise with a mile high mountain (Mt. Katahdin) out my front window! Thanks....glad the digits are back FF :)
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace


Re: Bi-metal damper questions

PostBy: VigIIPeaBurner On: Sun Jan 12, 2014 2:57 pm

A little late to the party but here's a few question for you to answer if you could.

  • I know this seems crazy but is the chain hooked to the end of the coiled bimetallic coil and the center hooked to the lever? The chain is hooked to the end of the coil and the the coil tension is increased or decreased by moving the lever
  • When you push the flap control lever toward the stove pipe collar, does the flap close and the chain go limp?
  • Conversely, when you move the flap control lever away form the stove pipe collar, does the flap open and the chain get taute?
  • You refer to there being more draft from the floor below. Is this the same flue and is the opening form the lower floor completely sealed off? Not likely your problem if the stove is reaching 700* on the griddle.
  • Do you have a manometer reading of the draft with the 2310 hooked up and warm?
  • Are you closing the internal damper after the griddle reaches 400-450*? The heat needs to go thru the side and back passages to better regulate the 2310.
  • If you are closing it, does it seal against the back plate when closed?
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Zoom in a little to see the chain attachment point tab on the left side of the bimetallic coil. Heat shield, adjustment rod and coil are visible. There are tw heat shields visible; the silver one for the thermostat closest to coil and the stove back shield.
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VigIIPeaBurner
 
Hot Air Coal Stoker Furnace: Keystoker Koker
Hand Fed Coal Stove: Vermont Casting Vigilant II 2310
Other Heating: #2 Oil Furnace

Re: Bi-metal damper questions

PostBy: franco b On: Sun Jan 12, 2014 3:36 pm

See that the clip that holds the chain is in line with the bi- metal coil. If facing toward the front of the stove it can hang up on the stove protrusion that the thermostat lever is fastened to.

Move the lever and observe if the clip is free through out its travel and that the flap is opening and closing.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

Re: Bi-metal damper questions

PostBy: michaelanthony On: Sun Jan 12, 2014 6:08 pm

[quote="VigIIPeaBurner"]A little late to the party but here's a few question for you to answer if you could.

[list][*]I know this seems crazy but is the chain hooked to the end of the coiled bimetallic coil and the center hooked to the lever? The chain is hooked to the end of the coil and the the coil tension is increased or decreased by moving the lever

[*]When you push the flap control lever toward the stove pipe collar, does the flap close and the chain go limp?

[*]Conversely, when you move the flap control lever away form the stove pipe collar, does the flap open and the chain get taute?

[*]You refer to there being more draft from the floor below. Is this the same flue and is the opening form the lower floor completely sealed off? Not likely your problem if the stove is reaching 700* on the griddle.

[*]Do you have a manometer reading of the draft with the 2310 hooked up and warm?

[*]Are you closing the internal damper after the griddle reaches 400-450*? The heat needs to go thru the side and back passages to better regulate the 2310.

[*]If you are closing it, does it seal against the back plate when closed? [/list][/quote]

Let us first establish the movement of the control lever parameters as 10:00 and 2:00 and 2:00 being closest to the flue collar.
Everything is connected as needed. When I move the lever away from the flue collar the draft flapper opens but not until the the lever is almost 12:00. So is the chain too long?
When the control lever is moved to the 10:00 (full throttle), the damper flap is not fully open, about 60% and the chain is taute,and when moved towards the flue collar the chain goes limp well before the collar, keep in mind this is with a hot stove 550*.
When I was speaking of the floor below it was in reference to the separate stove AND flue, tons of draft and installed mpd and baro in the stove in the basement.
I checked the draft with the Vigilant running @450* thanksgivings weekend and it ran -.03---.05 and steady never left those settings.
The direct draft is only used when heating up to load, ( I followed the videos ), and shaking and knifing the ash. The damper moves freely and sounds and feels to seat properly for indirect draft as well.
I have noticed the chain vibrating but the flap is always where I set it.
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: Rob R. On: Sun Jan 12, 2014 6:24 pm

It seems to me that if you turn the knob and the stove temperature changes, it is working as designed. :gee:
Rob R.
 
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice/buck
Other Heating: Dad's 1953 EFM Highboy

Re: Bi-metal damper questions

PostBy: VigIIPeaBurner On: Sun Jan 12, 2014 7:41 pm

Sounds like your chain could require some adjusting but I'm not yet certain. I've had this system for over 35 ( :shock: ) years and never had to calibrate one.

I can offer the following. I've measured my draft other years, not lately, and it's a very strong -0.10 measured at the "secondary" air inlet on the left side. You see in the bottom pic. What I'm showing in the following pictures are relative to that reading and outdoor conditions of 40*F and breezy on a 640' hilltop with the barometer reading 29.99 and raising.

    with the rod at 12:00 ...
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    See the red laser dot on the stove's cast graphic range indicator . . .
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    ... The griddle center read ~600 and the temp of side chamber is as the mag unit reads 330 ...
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    ... And the flap is open about 1/4" 6 hours after adding 12 Lbs of nut. Last shake was 20 hours ago . . .
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When I can, I'll report back on how many links or distance between both points.
Last edited by VigIIPeaBurner on Sun Jan 12, 2014 9:16 pm, edited 1 time in total.
VigIIPeaBurner
 
Hot Air Coal Stoker Furnace: Keystoker Koker
Hand Fed Coal Stove: Vermont Casting Vigilant II 2310
Other Heating: #2 Oil Furnace

Re: Bi-metal damper questions

PostBy: michaelanthony On: Sun Jan 12, 2014 8:49 pm

Ok... thanks Dave, I have 500* on the griddle top and 275* center of the left side and 300* center of the right side and the flapper is open about 3/8 of an inch. Standing in front of the stove the lever is located at 11:00 so it looks like there is some slack in the chain to take out. It sags considerably when the lever is pushed against the stove collar. My thought's are this: I can load the stove and run it up to 700* plus, set the damper at approx. 1/4 inch open and the stove will creep up to 725* on the griddle and stay there...well the damper is still at 1/4 inch open. At what point does the bimetal spring say "hey it's getting hot time to close." I was doing this at various temps with the damper wide open and then gradually closing the damper myself to keep the temp at my desired spot. Question then, does the spring only actuate at very high temps and not the middle of the road? I hope I am making sense because I can set my box stove with the vents above the ash pan and it will stay there without running up in temp with no bimetal spring.
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: michaelanthony On: Sun Jan 12, 2014 8:51 pm

[quote="Rob R."]It seems to me that if you turn the knob and the stove temperature changes, it is working as designed. :gee:[/quote]

Don't get me wrong Rob, the stove works great but I don't see any movement with the bimetal spring. I have been laid off so I can make adjustments as needed but at what point or I should say temp, does the bimetal spring do that for me?
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: michaelanthony On: Sun Jan 12, 2014 8:57 pm

[quote="franco b"]See that the clip that holds the chain is in line with the bi- metal coil. If facing toward the front of the stove it can hang up on the stove protrusion that the thermostat lever is fastened to.

Move the lever and observe if the clip is free through out its travel and that the flap is opening and closing.[/quote]

Sorry I missed this franco, the clip on the spring is free and clear and the flap opens and closes fine. I'm expecting flapper movement but when temps change in the stove 50* to 100* I'm the one doing the moving.
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: franco b On: Sun Jan 12, 2014 9:25 pm

You should not judge by the flap but rather the lever. What happens when you set the lever straight up at 12:00 and leave it there? The lever is hyper sensitive in that a 1/16 movement makes a big change and yes the bi-metal responds slowly and the stove temp. will overshoot before settling down to a steady temperature when reloading. This is a good thing as it helps to burn those initial volatiles before settling down to the set output. Far less chance of puff back than with a manual fixed setting. 12:00 should give a stove top of 5 to 550.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

Re: Bi-metal damper questions

PostBy: VigIIPeaBurner On: Sun Jan 12, 2014 9:38 pm

MA, the bimetallic control is a coil that slowly changes length. It won't snap the flap shut. You don't want it to shut except on its own accord to hold the temp in the zone you're targeting. Depending on your draft, coal size and quality the flap will stay open some unknown distance to maintain the temp set point. Trick is to find those combinations. ;)

I originally set mine by trial and error to operating conditions/temperature targets. I'd open it and once the stove got close to target temp, I'd close or open the flap to ~1/8" then let it ride for hours, 6 or more, until I confirmed temp settled in. The room temp needs to stabilize before I'd tweek it as needed. These (now) known set points will only change a little depending on the load due to outside conditions. If you open it too much, it will keep raising even after you shut it. Flap will close then, start to cool and swing too far to the cool side, then bounce up again. Creep up on it and let it ride. 8-)
Last edited by VigIIPeaBurner on Mon Jan 13, 2014 7:16 pm, edited 1 time in total.
VigIIPeaBurner
 
Hot Air Coal Stoker Furnace: Keystoker Koker
Hand Fed Coal Stove: Vermont Casting Vigilant II 2310
Other Heating: #2 Oil Furnace

Re: Bi-metal damper questions

PostBy: michaelanthony On: Mon Jan 13, 2014 8:03 am

Thanks franco and Vigil, I knew it was one of two things, the stove or me, and the stove is fine! :lol:
michaelanthony
 
Hand Fed Coal Stove: Vigilant 2310, gold marc box, vogelzang pot belly
Coal Size/Type: Pea, and a little nut
Other Heating: Very cold FHA oil furnace

Re: Bi-metal damper questions

PostBy: freetown fred On: Mon Jan 13, 2014 8:42 am

Hmmmmm, the human element---who-da thunk??????????????? :clap: toothy
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix