EFM 520 Aquastat

Stoker Coal Boilers automatically feed the coal and have controls and pumps just like any conventions boiler. They are intended to be used as a primary heat and often have domestic hot water coils as an added bonus. They can be set up independently or in dual sytem with your existing oil/gas boiler. They can accommodate both hot water base board or steam plumbing.
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northernmainecoal
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Joined: Wed. Jan. 22, 2014 8:33 am
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Hitzer 30-95
Baseburners & Antiques: Herald Baseheater #6
Coal Size/Type: Rice/Nut/Stove
Location: Aroostook County, Maine

Post Wed. Jan. 22, 2014 8:39 am

I finished the install of our new EFM520 yesterday. I have programmed the aquastat at the following:
High limit- 195
Low limit- 177
Low limit differential- 12
The boiler is coming on at 195 and shutting off at 185, any idea why this would be? Am I programming it incorrectly? Is it possible there is an issue with the aquastat itself?
Thanks
Rob
Rob

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GoodProphets
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Posts: 219
Joined: Sat. Jan. 07, 2012 9:14 pm
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Anthra Rice
Other Heating: 3 Fireplaces
Location: Lanc Co PA
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Post Wed. Jan. 22, 2014 1:56 pm

Are you taking those readings posted from the aquastat or the gauge from the boiler?

Sounds like wiring is not correct.

I am not a wiring genius, so hold tight until pros come to help out.

Fill in your profile with location, etc, it could help in the future

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franpipeman
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Joined: Fri. Jan. 11, 2008 4:27 pm
Stoker Coal Boiler: efm 520 stoker fitzgibbons pressure vessel
Hand Fed Coal Stove: harman, russo
Coal Size/Type: rice
Other Heating: alpine propane condensing boiler radiant floor
Location: Wernersville pa

Post Wed. Jan. 22, 2014 2:06 pm

there are many different types of aqua stats what is the manufacture and model number?

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northernmainecoal
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Posts: 502
Joined: Wed. Jan. 22, 2014 8:33 am
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Hitzer 30-95
Baseburners & Antiques: Herald Baseheater #6
Coal Size/Type: Rice/Nut/Stove
Location: Aroostook County, Maine

Post Wed. Jan. 22, 2014 2:08 pm

My plumber just called with what he hopes is the answer. The 520 is piped in with my existing oil boiler because of this we are constantly circulating water between the two boilers. In order to do that the TT has to be jumped on the aquastat which is also the reason it is acting funny (that's my understanding of what he had to say at least) Without looking at the aquastat I believe is an L7224A, but I'll double check when I get home
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Rob

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stoker-man
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Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove
Location: Lehigh Valley, PA

Post Wed. Jan. 22, 2014 3:19 pm

You should move the high and low limit settings apart by 40 degrees or you may have trouble with your fire going out. 20 degrees doesn't work with coal when the temperature is more moderate.
‹(•¿•)›

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Rob R.
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Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Wed. Jan. 22, 2014 4:57 pm

If you short the TT terminals the aquastat will try to keep the boiler temperature at the high limit setting...which is what you are observing. At 195 it will shut down the stoker, when it gets to 185 (high limit differential is fixed at 10 degrees) the stoker will resume operation.

The way your plumber has it setup will work, but I prefer to connect the TT terminals to the end switch of the zone relay(s).

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McGiever
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Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
Coal Size/Type: PEA / ANTHRACITE
Other Heating: Ground Source Heat Pump
Stove/Furnace Make: Hydro Heat /Mega Tek
Location: Junction of PA-OH-WV

Post Wed. Jan. 22, 2014 5:02 pm

Is it a typo? He says On @ 195...and Off @185 ???
SLOW AND STEADY WINS THE RACE

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Rob R.
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Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Wed. Jan. 22, 2014 5:11 pm

McGiever wrote:Is it a typo? He says On @ 195...and Off @185 ???
I assumed it was a typo. if not, I have no explanation.

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northernmainecoal
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Posts: 502
Joined: Wed. Jan. 22, 2014 8:33 am
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Hitzer 30-95
Baseburners & Antiques: Herald Baseheater #6
Coal Size/Type: Rice/Nut/Stove
Location: Aroostook County, Maine

Post Thu. Jan. 23, 2014 1:17 pm

Yes it was a typo, sorry
To fix the issue we removed C1 and C2 connections and put them on L1 and L2 so if the boiler has power the circ will run. removed the jump from the TT terminals and all is well
thank you
Rob

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Rob R.
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Posts: 11350
Joined: Fri. Dec. 28, 2007 4:26 pm
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Coal Size/Type: Lehigh Rice
Other Heating: Dad's 1953 EFM Highboy
Location: Chazy, NY

Post Fri. Jan. 24, 2014 4:34 pm

That is fine...as long as the heating load doesn't drag the boiler down to a temperature less than desired.

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northernmainecoal
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Posts: 502
Joined: Wed. Jan. 22, 2014 8:33 am
Stoker Coal Boiler: EFM 520
Hand Fed Coal Stove: Hitzer 30-95
Baseburners & Antiques: Herald Baseheater #6
Coal Size/Type: Rice/Nut/Stove
Location: Aroostook County, Maine

Post Fri. Jan. 24, 2014 4:53 pm

Its been working beautifully. The temps here have been 20-30 below with the wind chill this week. Even with constant call from the t stats its been maintaining the LL seemingly effortlessly. I'm considering dropping from 4 teeth to 3
Rob

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