Boiler Mate

 
Pacowy
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Location: Dalton, MA
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Post by Pacowy » Tue. Aug. 20, 2013 2:49 pm

I don't want to mess with Rob, but I'll still vote for the 7 gpm coil. It is a few more $ up front, but I think its larger surface area would let you produce any given DHW flow rate with a lower boiler water temperature, so you'd save on standby losses. And it provides extra capacity in case you want to run the dishwasher or laundry, have people take showers, or carry whatever other DHW loads you have. Plus, it was the original equipment spec'd by EFM for 700's, and is called for under the Massive Overkill Doctrine to which I subscribe. :lol:

Mike

 
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Rob R.
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Stoker Coal Boiler: EFM 520
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Post by Rob R. » Tue. Aug. 20, 2013 3:48 pm

I was trying to be cost sensitive. If the funds are available, use the 7 gpm coil. If even more funds are available, look at an indirect.

This boiler is in a remote building, so I assumed there would not be additional DHW load during the pressure washing.

 
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Scottscoaled
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Location: Malta N.Y.
Stoker Coal Boiler: EFM 520, 700, Van Wert 800 GJ 61,53
Baseburners & Antiques: Magic Stewart 16, times 2!
Coal Size/Type: Lots of buck
Other Heating: Slant Fin electric boiler backup

Post by Scottscoaled » Tue. Aug. 20, 2013 5:58 pm

Boiler is in attached mother of all god garage.


 
Mark (PA)
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Location: South Central, PA
Stoker Coal Boiler: 1953 EFM520 Highboy

Post by Mark (PA) » Wed. Aug. 21, 2013 9:29 pm

I like my 7 GPM coil... ;) while your doing it....

 
Phil May
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Location: Wellsville NY
Stoker Coal Boiler: EFM 700
Hot Air Coal Stoker Stove: Liesure Line
Coal Size/Type: Rice

Post by Phil May » Thu. Aug. 22, 2013 4:39 pm

Yes the water is hard but it has not been a problem with my appliances and we built the house in 1997. I am going to try the coil. I am going to mix the water at the spicket. I am going to use 3/4 in and out for the coil.

 
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lsayre
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Location: Ohio
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Lehigh Anthracite Pea
Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75

Post by lsayre » Thu. Aug. 22, 2013 6:02 pm

I would add a proper mixing valve so you don't get scalded. There are several good brands. This is the one I have:

http://www.pexsupply.com/Taco-5003-C2-3-4-Sweat-5 ... xing-Valve


 
daluds
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Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice

Post by daluds » Wed. Sep. 18, 2013 7:02 pm

I ran the hot water from the DF520 7gpm coil to a Marathon 85 gallon hot water heater as a big capacitor. Works great even with the Marathon heating element off. My wife says this is the best space capsule I have ever bought since it keeps her soaking tub filled with hot water. No more angry faces or threats to replace my DF520 boiler(or was that me?)! Coal just takes too long to heat up to keep up with lots of domestic hot water. When its on oil its fine, but not on coal. Takes a while to get the coal nice and hot!

Image

 
Pacowy
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Posts: 3555
Joined: Tue. Sep. 04, 2007 10:14 pm
Location: Dalton, MA
Stoker Coal Boiler: H.B. Smith 350 Mills boiler/EFM 85R stoker
Coal Size/Type: Buckwheat/anthracite

Post by Pacowy » Wed. Sep. 18, 2013 7:47 pm

To handle big DHW loads with a coil you need to make sure the feed/air rates and low temp limits are set accordingly. In our old house we used a coil in an EFM 900 and it made infinite hot water for a family of 8 without breaking a sweat.

Mike

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