*#@& Bimetal t-stat!

*#@& Bimetal t-stat!

PostBy: LDPosse On: Thu Jan 24, 2013 1:40 pm

I had to do a little poking around in the firebox today, I had a few clinkers to pull out. After doing that, and shaking down the ashes, I only had about 1/2 a firebox of coal left. I put on a couple shovels of UAE's finest, let it get to temp... put on a couple more, let those get up to temp, then fill the hopper.

About 20 minutes later, I smell the fresh scent of curing stove paint. I go down to check the stove, and the fire is ROARING, the secondary burn flames were the whole height of the door. The 2x wall Duravent DVL was SMOKING and I gave it a quick shot with the infrared -- 620 Degrees!!! :shock:

I promptly turned the t-stat back, cutting off the air to the fire. I stepped outside and there was smoke billowing out of the chimney, probably soot from the bitty I had been burning last week catching fire. Luckily, within a few minutes, everything was back to normal and I'm here typing this message.

So anyway, I thought these bi-metal t-stats were supposed to be "set it and forget it", but at the higher settings, it seems to have a very nasty tendency to want to overshoot after re-loading. I guess from now on I will have to dial the 'stat back when loading if the air flap is open too far.
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola

Re: *#@& Bimetal t-stat!

PostBy: Bootstrap On: Thu Jan 24, 2013 4:10 pm

Thats unusual. In my case, I was reloading the Hitzer one time and I needed to leave the ash door open for a few minutes to let it ramp up. Well, I forgot to shut the ash door....my girlfriend...naked...nature called.. Anyways in the not too distant future, I remembered that I left the door open :shock: and promptly went down stairs to get things in order. Stove was hot. The by metallic had the flap shut and it had tried so hard to cool the stove down that the chain was very slack and laying on top of it.... heh. Gotta pay more attention I suppose.
Point in case, well the t-stat was working for me, tried hard to cool off the stove but the ash pan door was wide open......
Bootstrap
 
Stove/Furnace Make: Hitzer
Stove/Furnace Model: 30-95

Re: *#@& Bimetal t-stat!

PostBy: hman On: Thu Jan 24, 2013 4:16 pm

That's what I do on a reload,if the thermostat is open to much I back it off some and bring up the temp a little slower.Cause it will over shoot.
hman
 
Hand Fed Coal Stove: D.S.Machine 1400
Coal Size/Type: Lump/Bituminous
Stove/Furnace Make: D.S.Machine
Stove/Furnace Model: # 3 circulator stove

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Re: *#@& Bimetal t-stat!

PostBy: ridgeracing On: Thu Jan 24, 2013 10:21 pm

With past weeks temps in the teens at night I have been running mine wide open at number 5 on bimetal stat and have stove temps of 500-550. During reloading it drops to 450 and then miutes later is up to 550-600 for a few minutes and then settles back to 500-550 for 12-14hrs. That is with MPD closed 90% all the time and temp guage is behind hopper door by stove pipe exit. Basement is 76deg and ranch level is 70-72deg. Very happy with stove!

What are your stove temps with your 600deg. chimney temp? I just checked my chimney (signal wall) temp 2 ft above stove (300deg.) and stove is 500deg.
PS- Burning a bucket and a half every 12hrs, usually 1 bucket at 30-40deg. outdoor temps
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

Re: *#@& Bimetal t-stat!

PostBy: LDPosse On: Thu Jan 24, 2013 11:10 pm

RR - how many balls on the chain is the air inlet door set at? Mine was at 6.. I backed it off to 3, and now at Hi on the bi-metal stat is what 3.5 was with 6 balls. Not sure if it will make any difference or not in how the stove reacts. I may try backing off the MPD a bit, I normally leave it wide open, and my chimney has a crazy strong draft. I think more than the stove was designed for.

My stove temp where you mentioned was cooler than the stove pipe was. I think the temp climbed so fast, that the comparatively thin gauge steel of the stove pipe heated up quicker than the thick steel of the stove.

I have been off work sick the past 2 days, so I just keep topping it off every 6-8 hours, I know it's using noticeably more coal. Keeping it 75 degrees on the first floor, maybe I can sweat this cold out! :yearight:
LDPosse
 
Stove/Furnace Make: DS Machine, Warm Morning
Stove/Furnace Model: DS1500, Heatrola

Re: *#@& Bimetal t-stat!

PostBy: ridgeracing On: Thu Jan 24, 2013 11:28 pm

I am clipped on 7th ball showing. I think with your strong draft you could close your MPD, mine has been closed all season, drafts great!
If you are on 6th ball, I would only lower it to 5th, 1 adjustment ball makes a big difference! I set mine so that when its set at max #5 the stove is 550-600deg. tops. That way it is still at a safe setting incase it flares up for some reason. Its OK to go 600-700deg. for short periods, just not hours on hours. On this setting I have had it as low as 200deg. stove temp on dial # 1 1/2 for warmer outside temps. Good luck with your cold! :cry:
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

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