EFM 350-520

Could some one tell me what the specs are on these two units. BTU'S ,WEIGHT ,OVER ALL DIMENSIONS. Thanks Coalboy

42" long (without the coil, 41"), 25 3/4" wide and 27 1/2" high.

Gross output 220,000 BTUH, Net output 188,600 BTUH

Total weight 1300, with the boiler being the heaviest at 800#, 5/16" boiler plate.

The 350 is a smaller version of the 520. They are only available in used condition.

Contact scrapper_23jr on this forum for a used 350.

The EFM 350 is one unit that is sized better than the EFM 520 for modern homes. I have heard the sales pitch that the 520 can be gear down. But the 520 unit is far overkill for today’s better insulated homes. Bigger is not always better when it comes to efficiency, otherwise Big Cars would get as good mileage as smaller cars. Make the unit work harder and the efficiency will go up. This is from a person who is an mechanical engineer and understands the laws of science not Sales Hype. EFM Bring the EFM 350 back into PRODUCTION

We have made that opinion LOUD and CLEAR to the company. We are re-introducing the hand-fired WCB-24 and there is a smaller boiler being looked at to fill the 350 gap.

Just like everybody else in the stoker business, we are way behind on our orders for the 520, but I will keep sending the message to the company.

The 350 is the same height as a 520, it is 2" narrower, and 4" shorter,, may hold 5-10 gallons less water,, the stoker is the same as the 520, just set to be limited to 15# of coal per hour instead of 25# per hour..

So maybe the boiler would use $20-$50 dollars less steel, take the same time to build, have the same number of parts, stoker, and labor,, and to what effect?? with tooling up costs, it would be the same cost as a 520.. and no more efficient..

The very slight reducttion of heated surface area in the boiler is not going to make this smaller boiler any measureable amount more efficient.. If the boiler was say 25% smaller, maybe the steel savings would be worth a few hundred dollars off the purchase price..But reducing the heated surface area does not make for more efficiency, nor does a smaller stoker, not with the EFM design. Now with an AA boiler, using a 260 where a AA130 would work is probably going to cost you some unburnt coal.. but not with the underfeed pot design in an EFM.

But I'd not hold my breath waiting for EFM to start another product line up, when they are selling all they can produce, and have a bituminous experiment ongoing..

Greg L.

Somewhere on this page was a pdf which gave measurements, heating capacities etc. etc of the popular older style boilers such as EFM AA etc. http://www.heatinghelp.com/library.cfm

Read Thae last Post on the first Page I have all of the sizes for all of the EFM stoker boilers models except The 520 Highboy

EFM, Keystoker, or AHS