EFM Summer Settings for Domestic Hot Water

Re: EFM Summer Settings for Domestic Hot Water

PostBy: Pacowy On: Wed May 30, 2012 5:15 pm

whistlenut wrote:Having two AA 260's running 24/7-365 in a ten apartment complex, I can tell you tank-less coils will provide plenty of domestic hot water, HOWEVER the demand, once satisfied, makes it impossible for a boiler to 'ramp down' quickly enough to prevent overshoot....and overheating. Doesn't matter who's boiler it is.....so, a dump zone......or use of a big indirect and some tankage sure helps out. My 520's and 900 were set at 4 clicks, 4.5 air burning buck. AHS, AA, Keystoker and now LL work just fine without major adjustment.

Remember, this is a perfect time of the year to shut it down, clean stack piping, replace as necessary and vacuum out the boiler and passages. :idea:


I never had the 900 making steam after "overshooting" on a big DHW run. Are you saying there's no difference between the EFM and AA-type boilers on this? In another thread it was discussed in detail how the fire being in contact with the boiler vessel (as I understand it is in an AA) differs from the EFM in terms of heat transfer at idle.

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

Re: EFM Summer Settings for Domestic Hot Water

PostBy: vermontday On: Wed May 30, 2012 9:33 pm

Just finished the re-wiring (had to work late, barbecue dinner and look for the neighbor's missing dog, if you see a non-Japanese Datsun in the area, call me!).

Rob's idea to get the Superstor off from the main boiler aquastat was a good one. I don't know why I didn't think of it.

The main boiler L7224 aquastat was pulling in the circulator for the superstor, so I rewired it to be pulled in off a separate RA89A relay and transferred the TT wires to the separate relay. I also raised the LL from 130 to 140 degrees now that the boiler temperature will control off of it.

Upon calls from the Superstor, the circulator drew the boiler water temperature down from 198 to 130 degrees, when the stoker came on.

After satisfying the Superstor demand, the stoker turned off at 140 degrees. I will probably raise the LL higher to 150 to make sure there is a good differential temperature to the Superstor.

This is great! My boiler has'nt seen these low temps in quite awhile! I had to override my outfire aquastat for tonights run. I will lower the setting on that.

The Superstor piping and zone valve are 3/4". It was already here when we bought the place.

I will check for buildup in it this weekend.

Thanks Rob!
vermontday
 
Stoker Coal Boiler: EFM 520

Re: EFM Summer Settings for Domestic Hot Water

PostBy: Rob R. On: Wed May 30, 2012 9:36 pm

You're welcome.

:rockon:
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: EFM Summer Settings for Domestic Hot Water

PostBy: vermontday On: Thu May 31, 2012 7:23 pm

Boiler temperature of 193 degrees this morning, 168 degrees when I got home tonight.

Since last night, outfire timer has come on 11 times, dump zone 0 times.

Excess heat appears to be solved. We now can relax all summer knowing that we are burning minimal coal!

Still would be interesting to hear what settings and tips others have for summertime.
vermontday
 
Stoker Coal Boiler: EFM 520

Re: EFM Summer Settings for Domestic Hot Water

PostBy: CatholicBoy1957 On: Fri Jun 01, 2012 7:55 pm

I don't think the older stokers, like I have, are capable of the kind of simple teeth adjustment that the newer ones have, so I think my dad always left the settings the same all year around. I think there is one adjustment for feed, by changing the position of the arm on the fulcrum coming out of the gearbox, but I doubt if it's been used ever. I can't say I've never had an outfire, but it seems rare. I don't believe there is the ability on this hookup for dumping heat. I hate to admit, but I don't even know how often it runs in the summer, but it ain't often, unless I use water.
CatholicBoy1957
 
Stove/Furnace Make: EFM
Stove/Furnace Model: 1967 AP520-1 & S20

Re: EFM Summer Settings for Domestic Hot Water

PostBy: Pacowy On: Fri Jun 01, 2012 8:19 pm

I think changing the position of the arm, as you describe, performs the function of the feed control collar on newer units. I had the older set-up on my 900 - it worked fine.

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

Re: EFM Summer Settings for Domestic Hot Water

PostBy: Rob R. On: Fri Jun 01, 2012 8:31 pm

CatholicBoy1957 wrote:I don't think the older stokers, like I have, are capable of the kind of simple teeth adjustment that the newer ones have, so I think my dad always left the settings the same all year around. I think there is one adjustment for feed, by changing the position of the arm on the fulcrum coming out of the gearbox, but I doubt if it's been used ever.


<removed dead links>

The older style may not be as fast to adjust, but it works perfectly fine. If your heating needs can be met with a modest feed rate, it is easiest just to leave it alone and adjust the timer and/or aquastat if needed.

Pictures are courtesy of forum member Matthew D.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: EFM Summer Settings for Domestic Hot Water

PostBy: vermontday On: Tue Jun 12, 2012 8:36 pm

Just an update for those reading this thread, now that the superstor is wired off it's own relay and not off the boiler aquastat, it no longer pulls the stoker on immediately.

This results in the boiler stoker not coming on until the boiler water temperature reaches the low limit. This made a world of difference with the boiler now running at the low temperature end instead of being near the high limit all the time.

This allows me to run the outfire (hold fire) timer more often with no worry of heating up to the high temp limit. At 3 teeth 3 air, 150 LL, 200 HL, I now am using a setting of 30 minutes for the outfire timer with it running the stoker for 2-1/2 minutes.

The dump timer is set at 40 minutes and it is set to run the stoker for 20 minutes. As it would only come on when the stoker could not run on the outfire timer due to being at the high limit, it never has to come on anymore, saving me fuel.

Both timers will reset to 0 if there is a natural call for heat.
vermontday
 
Stoker Coal Boiler: EFM 520

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