My 520 Project

Probably put you on hold for a quick smoke break. lol. Air scoops are great to remove large amounts of air when the system is new. If you never leak water, you'll never get much use out of your scoop anyway, so why the big deal? Use a tiny air vent on top of the boiler or a vertical pipe and you'll accomplish the same thing.

Until recently, I'd bet that most people made the "mistake" of putting the circulator on the return line. I have two "mistakes" in my house and it's just as warm as the guy who didn't make any "mistakes". It's not a pump, it's a spinning wheel, like a bathroom ceiling fan. It (Taco 007) just gently moves water along and it's been doing a great job for me for a ton of years.

I've read all the books and pump manufacturers recommendations on where to put the circulator. All say pumping away style and that's how I piped my primary secondary two boiler system. BUT, I had to move my coal boiler circulator to the return side. Why? Because in my installation the primary secondary piping loop is lower than the coal boiler supply tap and safety relief valve. When I had an overheat temperature condition the safety blew, venting the water. The boiler cooled and the auto fill valve pumped in more water. BUT, my circulator is a Taco 007 IFC, (internal flow check). This prevented water from getting to the impeller side of the circulator. NO impeller water, NO GO, NO Heat. Moving the coal boiler circulator to the return side, even with an open safety there is water on both sides of the circulator. So, like Sting says, it depends.

Interesting in Sieganthaler's book almost all of his multi-boiler diagrams using primary secondary piping show the circulator for each boiler on the return side. He doesn't say why.

Another reason for circulators being on the return side was that the water was cooler. Controlling the heat on my hand-fired boiler isn't easy and I've had 230+ degree water hitting the supply side circ. before I made a dump zone. The circ. lasts about 2 years before it chatters. The return circ. at the other end of the house remains like new.

Rob R. wrote:It probably had a B&G series 100 circulator, which has a very flat pump curve. If you put a high head circulator on the return of a system with lots of resistance to flow, it is possible to have serious air problems and/or cavitation.

B&G used to have a great video that demonstrated this...too bad I can't find it.

That's why I installed the circulator on the return side on the EFM. The house I grew up in had an American Radiator/Standard Sanitary gas boiler in it, one zone, cast iron radiators, and a B&G series 100 circulator on the return side. I figured that's the way it's done, but I understand the reasons for plumbing it differently.

With regard to the Taco air scoop, I understand the reason for having a straight run of pipe on the inlet and the outlet, in my installation I didn't have enough room, so I chose to have the straight run on the inlet side. So far it seems to be working fine. If I had the space I definitely would have straight runs on either side.

http://nepacrossroads.com/download/file ... &mode=view

It's not perfect I admit, but it seems to work reasonably well.

Every single house I've ever been in or lived in on the east coast had the circulator on the return side. Right or wrong, it works.

Thanks for all of the replies. There certainly is a lot to consider. I truly appreciate all of the input. The plumber will be returning soon. We shall see what we end up with. It could end up being "one big mistake". More to come later.

Finally reached that point at 7pm Thursday (5 hours ago) where I could light the first fire. The weatherman is calling for cooler temperatures and frosty mornings for the next week which will give me a chance to put her to the test. The fire started very easily with a small amount of charcoal. Settings of 4 teeth and 4 air seemed to work well from the start. Only a little tweaking of the barometric damper to keep the draft in the 0.04 to 0.05 range was necessary. I am amazed at how quietly it operates. I am burning Reading which is available close to my location. I am very pleased with EFM 520.

Congratulation on getting to the point of lighting your "First Fire"

Where did you find the Reading Coal supplier? Do they sell bulk and bagged, both?

I purchased my coal from Heet Inc. that distributes to several locations in Western Pa. What they have depends on the location. The following website lists the locations and what they have:

http://heetinc.com/index.html

They also sell Reading Stoves and Keystokers. Paul, the owner, is very knowledgeable and helpful. Their phone # is 724-228-3710.