Finally Installing my EFM 520...Few questions along the way

Alittle background to bring up to speed:

9 months ago I bought this EFM 520 from Glen on here and had planned to put it in as my summer project. Well, life happens, and 9 months later, finally getting around to it. I had a few other things I had to do first before and in order. 1)relocate well-saver tank, build basement coal bin, then install boiler body, now getting to the plumbing. I bought the collection of books recommended, since Im a virgin to all this. Learned a good deal, adjusted my initial layout plan applying the primary-secondary piping setup while pumping away from the boiler. Pretty much stole the layout right out of the book. lol.

Anyway, I was maching up all the piping and laying it outin the basement tonight and went any further and sweat the pipes together, I wanted to get some input into the layout. See if im missing anything. Particularly because there are some other setups that ive seen what look to be different square-shaped gauges on the 'sending stalk' out of the top of the boiler that i wasnt sure what they were...and being i dont have anything there, I was wondering if Im missing something.

Just wanted some outside opinions on the setup before I start making it 'permanent'.

My drawn schematics:



The book's:


Put into reality:




I have a couple questions so far about some of the Other parts.

-Im still learning about the Aquastat. Does it need to screw into the boiler/pipes like the temperatur gauge does, or just strap to the outside of a pipe? If it threads in, I dont seem to have a spot to connect it? Unless I move the temp/press. gauge to the 'sending stalk'?

-Any suggestions for remove the plugs that have been sitting in it for who knows how long? I tried using a large pipewrench on the top plug(wher ethe boiler air valve will go) and it actually chipped the corner a bit.




Still pretty much completely clueless on the electrical wiring/components i need and how they work. but I guess I'll get there once I get the plumbing done. I just hope its before Xmas...I really dont want to pay for oil again this year.

Any pointers? observations? suggestions?

A few thoughts.

1. Install the aquastat well where the temperature gauge is currently...move the gauge to one of the two tappings to the right. There may also be a tapping on the back next to the tankless coil that can be used for the aquastat.

2. You should have 18" of straight pipe before the air scoop. A lot of people never have more than 12" due to space constraints, but 18" is the rule.

3. You shouldn't have that 90 degree elbow between your secondary zone connections. You want the two tee's with no more than 6" between them, with straight pipe before, between, and after the tee's.

4. That circulator shouldn't have the motor facing down, only horizontally.

good stuff above from Rob

Ill add - split the return to vessel- use the branch off of a tee - then continue with equal fittings and nipples to each vessel return port for correct flow distribution

you did a good job reading!

large amounts of heat on those plugs -- or its safer to drill and collapse them

wiring controls --- eccchhhh the author of the books you read also published help on that it may be worth it as you did so well with the piping

Sting wrote:large amounts of heat on those plugs -- or its safer to drill and collapse them

Yep, the small plugs should come out with some heat and muscle. I have a very old set of 8-point sockets that works wonderfully for square-head plugs that haven't been previously disfigured.

Sting wrote:Ill add - split the return to vessel- use the branch off of a tee - then continue with equal fittings and nipples to each vessel return port for correct flow distribution

I missed that in the sketch. A lot of guys will say to just use one return port, because that is the easiest and cheapest way. I have installed EFM 520's three ways, one return port, two returns as shown in the sketch, and two returns with a tee and equal length piping to each. Pictures are below. If you are only going to run the stoker at 4 or 5 teeth it probably isn't a big deal, but if you are going to run it hard, I would definitely use both return ports as shown in the third picture. Regardless of output, the boiler temperature will be more uniform with both returns piped for equal flow...but this becomes more important with high boiler output and/or a higher temperature delta through the boiler.

Edit: You should also install a bypass between the supply and return pipe...It prevents stratification in the boiler during periods of low demand. Omitting the flow check in the primary loop may also work, but you wouldn't know until the boiler was online.

From the notes on the sketch it looks like you also have a oil boiler. If so, my choice for the primary loop piping would be different. I'd have a primary loop with a the air separator, primary pump and multiple closely spaced tees. One input pair for the oil boiler, one for the coal boiler and a third for the output loads. There would be three pumps, one in the primary loop and one each on the boilers. The boiler pumps would have internal check valves to prevent gravity circulation. Switching between oil or coal is simply an electrical switch, i.e. which boiler circulator runs. On the coal boiler I would put the down low on the return side. Why? Because if you get an over-heat condition and the safety blows you loose water. When stable conditions return, depending on the pumps location, the spring loaded check value doesn't allow water to get to the impeller and the pump will not pump. Having the circulator down low on the return, prevents this problem because a blown safety is unlikely to blow all the water out of the boiler and water is usually maintained on both sides of the pump. Be sure to size your expansion tank large. Large enough to hold expanded water volume from a overheat condition in your coal boiler. This will keep the safety from blowing. In effect your now very hot coal boiler reserves the heat for the next load demand condition.

Ok, so, im going to modify it some (hopefully reuse all the pipe) and add in the points brought up.

Changes:

-Add bypass loop from supply to return.
-18" of straight pipe before the air seperator
-No 90* between loops(will probably shorten the Primary loop too if I can)
-Try to heat those plugs ...otherwise, guess I'll drill.


New Questions:

-Yanche: I read and re-read your post several times trying to picture and understand(Im very new to all this). I THINK you are suggesting putting the primary circulator low on the return end of the primary loop, so that the zone pumps dont get starved of water in case of a blow? So the primary will, in a way, be pumping 'towards' the boiler, and the zone circulators will still be 'pumping away' from the boiler, correct?

- Does it matter which order I put the flow control valve, air seperatpr(as long as it has 18" of straight before), and primary loop circulator? Given the new suggestions,(and assuming i got what Yanche was suggesting) I'd like to put the flo valve first in place of the tee at the top of the initial vertical supply pipe, and use the two inputs as I would have used the 'T'...the after the 90* along the wall, have 18" of straight, then the air seperator, the the tees to the zones and tees for return, then the priamary loop circulator on the return-half of the primary, right before it splits to (2) 1" return lines.

Like This:


-If I split the returns, Being that the initial supply is 1 1/4" pipe, Is there any reason I cant make the split returns each 1" because the flow rate of the 1 1/4 is 14GPM and the combines rates of the (2) 1" pipes would be 16GPM. Logically, that should work, right?

aducarab wrote:-If I split the returns, Being that the initial supply is 1 1/4" pipe, Is there any reason I cant make the split returns each 1" because the flow rate of the 1 1/4 is 14GPM and the combines rates of the (2) 1" pipes would be 16GPM. Logically, that should work, right?

That would be fine.

aducarab wrote:
-Yanche: I read and re-read your post several times trying to picture and understand(Im very new to all this). I THINK you are suggesting putting the primary circulator low on the return end of the primary loop, so that the zone pumps dont get starved of water in case of a blow? So the primary will, in a way, be pumping 'towards' the boiler, and the zone circulators will still be 'pumping away' from the boiler, correct?

- Does it matter which order I put the flow control valve, air seperatpr(as long as it has 18" of straight before), and primary loop circulator? Given the new suggestions,(and assuming i got what Yanche was suggesting) I'd like to put the flo valve first in place of the tee at the top of the initial vertical supply pipe, and use the two inputs as I would have used the 'T'...the after the 90* along the wall, have 18" of straight, then the air seperator, the the tees to the zones and tees for return, then the priamary loop circulator on the return-half of the primary, right before it splits to (2) 1" return lines.

Here's how I suggest you pipe your primary-secondary loop.



More details here:

Yanche's Toolbox, Piping & Circulator Selection Method

Each supply boiler has a circulator with an internal check flow. It's on the return side on the coal boiler. It's on the supply side on the non-coal boiler. The primary loop circulator does not have a check valve.

Yanche, hello! Quick question. Why wouldn't the boilers be piped into the loop in the same manner that the loads are. Why would they be tee'd then enter the loop?

Scottscoaled wrote:Yanche, hello! Quick question. Why wouldn't the boilers be piped into the loop in the same manner that the loads are. Why would they be tee'd then enter the loop?

Depends on what you are trying to do. Method shown is for one boiler being used at a time. Your suggestion of them being both attached to the loop with closely spaced tees would be when both boilers are needed to meet demand.

Yanche wrote:

Scottscoaled wrote:Yanche, hello! Quick question. Why wouldn't the boilers be piped into the loop in the same manner that the loads are. Why would they be tee'd then enter the loop?

Depends on what you are trying to do. Method shown is for one boiler being used at a time. Your suggestion of them being both attached to the loop with closely spaced tees would be when both boilers are needed to meet demand.

What is the advantage of teeing them off? Being able to isolate them? That way would involve check valves? I don't see an advantage.

Scottscoaled wrote: I don't see an advantage.

Read a little more regarding hydraulic isolation and its benefits in multiple zone loads and heat sources

Sting wrote:

Scottscoaled wrote: I don't see an advantage.

Read a little more regarding hydraulic isolation and its benefits in multiple zone loads and heat sources

I think Scott was referring to the two boilers being tee'd into one set of "take offs" from the primary loop, rather that two separate sets of closely spaced tee's...one set for each boiler.

Scottscoaled wrote:

Yanche wrote:

Scottscoaled wrote:Yanche, hello! Quick question. Why wouldn't the boilers be piped into the loop in the same manner that the loads are. Why would they be tee'd then enter the loop?

Depends on what you are trying to do. Method shown is for one boiler being used at a time. Your suggestion of them being both attached to the loop with closely spaced tees would be when both boilers are needed to meet demand.

What is the advantage of teeing them off? Being able to isolate them? That way would involve check valves? I don't see an advantage.

I don't have the experience to comment on the practical difference between using multiple closely spaced tees or a single one and feeds teeing into it. I'm just showing what Siegenthaler shows in his book. Clearly both would work.

Sting wrote:

Scottscoaled wrote: I don't see an advantage.

Read a little more regarding hydraulic isolation and its benefits in multiple zone loads and heat sources

I'm not to a point where I have to read something