Installation of a stoker boiler at efm

I started this project several years ago, but never had time to complete it. For the past few months I've been installing Modine heaters and running pipe and now it's time to install the boiler. This step by step topic will show the process of installation, including the wiring, controls, oil kit, and jacket for a DF520 stoker. It is being installed to Labor and Industry standards for commercial use.

There must be 30" of walking space all around the boiler, no tripping hazards and no piping lower than 6 feet. It is necessary to dry-fit the boiler just to be sure nothing reduces the 30" space rule.

The pad is poured. The pad cannot encroach into the 30" walking space around the boiler. It must be at least 2" thick. If the boiler is being installed in an application such as a garage with flammable (gasoline)fumes, the boiler must be mounted on a raised pad. According to L & I, the fire in the pot must be 16" above the floor. (Never mind that the air intake for the fire draws air from a lower position ! ?)



After assembling the base, if an oil kit is going to be installed, install the three pieces of insulation into the base. It is held in place with 6 insulation clips. Install the pads with the cutouts first and the solid pad last. The new base uses pads that are one inch shorter in length, so if your need new pads, you must specify old style, one-piece base, or new style, assembled base. Any old style pad can be used in the new style base by cutting down the lengths. The base panels are held in place with two turnscrews. If installing the insulation pads after the steel panels are secured, I would hollow out an area in the insulation so the turnscrews can be turned for removal of the panel.

Set the stoker base onto the concrete pad and install the stoker to the appropriate mounting plate with 4 bolts and mount the plate to the base.

The air tube, burner pot, and cleanout rod and linkage are now installed and adjusted. The burner end tube and bin pipe collar should be attached at this time.

The boiler can now be set upon the base. Disregard the oil burner mounted on the left side. It is not to be installed yet. The perimeter of the boiler and all three base mounting plates must be well-sealed with boiler putty.

The return line, bypass piping and valves, pressure relief drain pipe, and boiler drain are installed. The return line is 1 1/2" and is on the left; the bypass piping is 1 1/4" to each tapping; and the relief valve is standard 3/4" piping which must come to within 6" of the floor; and the 3/4" boiler drain valve is on the right side. The return line must be at least 6 feet above the floor before any 90 degree turn.

The damper assembly for the oil burner can now be installed into the left side of the boiler. The oil burner cannot be installed until the jacket is assembled, which is the very last step of the installation.

The supply piping is now installed. The supply outlet was reduced to 1 1/2" and the first tee receives the bypass pipe. The second tee holds the low water cutoff probe. The probe must extend into the flow of water. Above that is a 1 1/2" union and the 1 1/2" isolation valve. The supply pipe must be at least 6 feet above the floor before any 90 degree turn.

After several weeks of wiring with no wiring diagram, just thinking in my head how I want to do this, it's done and inspected and confirmed as workable. Each boiler is separated by a double throw-double pole switch and shares one set of circulators. One is electrically disconnected while the other is powered. The entire system will draw 40 amps of power when using the waste oil boiler and 10 amps when using the stoker.

There was one problem when using the Honeywell R8888A circulator control panel. ZC of the aquastat is supposed to lose power when the water temperature goes below the low limit, thus shutting off the circulators. Using the panel, it does not. Honeywell has no solution except to add a relay, which will be to add yet another L6006C between ZC and the panel.



These two switches will separate the stoker and the waste oil boiler power, which are both on the same circuit.



Wiring for the 4 circulators.



Circulator panel - to the stoker - wiring.



Overall view of the wiring pertinent to the boiler installations.



The boiler room is now drywalled and painted.



The circulator manifold is complete.



It's been a few months, but the boiler piping is now complete and the unit is ready to have the jacket installed.



The supply header goes through the wall and into the circulator room, affectionately known as the "elevator shaft". The other pipe protruding from the wall will be the supply pipe for the waste oil boiler, yet to be installed. The supply header uses 2" pipe.



The expansion tank is shown and above it is the return header. There is a stub shown for the return line to the waste oil boiler, yet to be installed. The return header uses 2" pipe.



Beginning at the right side of the boiler, towards the wall, is the 1/2" copper water line, with the valve closed. Following that is the backflow preventor with a drain line, followed by the pressure reducing valve, and the line to the expansion tank, another isolation valve and the air separator in the supply line. The automatic air vent should be located in the front or rear port on top of the boiler for effective air elimination in the boiler. The blue box is the low-water cutoff.



The insulation is secured to the boiler with steel banding.



The cabinet support angles are installed on top of the boiler. The next four pictures are of the installation, in order, of the rest of the jacket.





Notice on the stoker side of the unit the support bracket along the bottom of the jacket and the hood mounting bracket, above the stoker.







The top panels are installed, along with the stoker hood. The cabinet is now complete.



The final wiring is done to the circulators.



The oil kit installation begins with the damper flange assembly.



The burner is attached with the 3 bolts and nuts and 6 washers supplied with the oil kit option.



The safety switch bracket is attached with the 2 self-tapping screws and 2 washers.



The electrical box is secured with 4 sheet metal screws. I had to cut the excess length off the screws to get the bracket back against the jacket.






The wiring is now complete. The power source for the stoker and the waste oil boiler is one 15 amp circuit. Only one boiler can be run at a time and both boilers share the same set of circulators, so they are separated electrically by two switches, shown earlier.

The boiler is wired for Labor and Industry, so there are controls used that wouldn't be used in a residential setting.

On the rear cover is the aquastat and a junction box. On the left cover, starting at the left is:

A junction box to supply connections to the L6006C above, which stops the circulator control panel from operating when the water temperature is below the low limit. For some reason, there is a problem with this Honeywell panel and the extra relay is necessary.

The Wilburt timer.

The DPDT switch box required to switch from coal to oil. Only one fuel can be burned at a time.

The junction box to distribute 120V. Directly above is the low water cutoff.

The power IN and emergency switch box.

The switch to override the outfire control.

Top position: The second high limit, resettable control. L6006E
Bottom position: The outfire control. L6006A

Not seen in this picture, the next safety switches are the damper position switch and the fire door switch, which prevent operation of the oil burner unless the damper is in the open position and the fire door is closed.



The burner worm and pipe collar are installed. It was a mistake to wait til now to install the pipe. It's impossible to wind the rope gasket around the pipe with the jacket in place. The pipe should be installed immediately when the pot is installed. In the picture below it shows how I was able to get the assembly installed with the jacket on. I left enough pipe above the collar to just enter the base and there was enough play to get the pipe collar through the round hole in the jacket. Then I was able to push the pipe all the way into the pot and secure the collar.





The construction project is finished on Friday, May 1st with the temporary coal bin in place. Testing and proving the system begins on Monday.

The system has four thermostats, four circulators, five Modine ceiling heaters and used many hundreds of feet of pipe and a couple hundred soldered fittings. It's also tied in to the electric boiler system for the office. It took about six months of steady work to complete and was actually started about 3 years ago.

I picked the brains of alot of people to do this project and I had to wing it most of the time without any plans and minimal drawings, but I hope it will be a help to anybody else installing their own system.

Once I install the other boiler and get it hooked in, I'll go back and rewire the controls and get rid of a few of the junction boxes. Extra boxes are one drawback of winging it.




I never had to start one of these things before, so I thought I'd try the same method I use to start my hand-fired unit.

I brought the coal in to the bottom of the pot to about one inch from the bottom of the grates or when I rebuilt the fire, I scooped out the coal to that level. I buried one of my firestarters in the coal and lit it and then placed a few pieces of pine board around it. In about a minute, the pine was burning as shown in the picture. Then I put coal all around the wood until it almost covered it, turned the coal feed lever all the way down to zero teeth, with the air setting at 5 and started the stoker. After about a minute, I was able to put a light layer of coal on top of the wood fire, then a little more and finally I put coal around the perimeter to cover all the air holes. I put the coal feed at 5 teeth the the stoker took over from there. Maximum time to start: 5 minutes.

Started up the system. The boiler water was 60 degrees, the outdoor temperature was 53 degrees with 87% relative humidity and raining, not the best conditions to fire up a cold boiler.

The stack draft on start-up was a neg. .01 and when the boiler was fully warmed up to 160 degrees, the draft had only increased to a neg. .04.

Smoke was pouring out of the coal bin using only the short burner tube, even with the lid in place, until the boiler warmed up.

Everything else checked out OK.

Clean install. Looks great! Good enginuity on the worm pipe collar! Thats a good tip!
Do you plan to insulate any of that copper?

KUDOS!!!!!! Great job! Very informative.

Do you think you used enough of stove gasket on the Auger tube you only need one piece that fits in the plate cruve and a piece inside the base around the tube and a piece on the drum end or in your case a ash can I also would of used a M or a RC baro Is that a RCBT I hope it is not a B-34 they are very in accurate

Sounds like a plan. I can change that when I install the stainless pipe that I forgot about. And how do you put the rope inside the base? Tape it to the pipe?

The baro is a Field control. Turns out the baro is fully shut and the maximum draft today was only neg. .04.

stoker-man wrote:Sounds like a plan. I can change that when I install the stainless pipe that I forgot about. And how do you put the rope inside the base? Tape it to the pipe?

The baro is a Field control. Turns out the baro is fully shut and the maximum draft today was only neg. .04.

Furnace cement or Hi temp silicone on the rope gasket then stick it to the pipe or stuff it inbetween the base plate and tube . I know it is a field control baro I asked what model RCBT or a B-34 A M model is what should be used on a coal unit
or a RC model The B-34 are inaccurate did you use a manometer to set up the baro if not do so As far as the smoke
coming out the ash can you need to warm up the chimney first before building a big fire you have no draft on a cold
chimney use paper & cardboard or small pieces of wood first to get the stack warm say 125f or 150f then build your coal fire you will not have any smoke coming out of the ash can plus keep the air setting down until the draft is up then kick the air up to your setting who's coal are you using that to will also determine where the air setting will be Plus the size of the coal Also are you planning to leave the wooded 2x4 forums on the cement pad I don't know if the code officer would like them there .

The wood frame is gone. The entire floor is wood. I'll have some steel plates made. I use a Bacarach draft meter for the draft. Very accurate.

I'm not all that worried about the smoke. With 6,000 sq ft of open space and just me in it, I didn't want to bother establishing the draft. Just fire it up and breath deeply.

The only insulated pipe is the loop to the office. Everything else is inside the conditioned space. The heat goes straight up to the 30 foot peak and works its way down

It's an RC control. Standard on all efm stokers.

I shut down the stoker overnight and restarted it today. It was a much different scenario the second time. The water temperature dropped to only 120 degrees and though the weather was exactly the same as the day before, there was no smoking this time due to the warmth of the boiler. I described the process in the original post.

I'm letting the stoker run overnight. There is a conflict with the circulator relay panel, the 6006C in between and the office heat circulator. I may have to have yet another switch to override the 6006C when I only want to heat the office and not the rest of the area.

I checked and the 3 wraps of rope around the pipe are what was the original design.

stoker-man wrote:I checked and the 3 wraps of rope around the pipe are what was the original design.

Yea why don't you get that much 3/8 rope gasket when you buy a new unit there is only enough to fill the gruve in the auger tube plate once. Why three wraps because the original design had a big heavy round plate that had more space to fill in between the auger tube and base plate The new one is a little thin Sq plate only need one wrap to fill it

26" of rope has, and still is, supplied with every new boiler to seal the pipe.

I fired up the stoker yesterday and was running at 8 teeth and 7 air. All I got was a huge pile of coal, large dark center, with live coal falling off the edges. Increased the air to 10 with no results. I pulled the ash pan and it was filled with black, partially unburned coal. By then, it was time to go, so I shut it down for the night.

This morning I cleaned all the burner plate holes and started up again at 7 teeth and gradually moved the air to 10. Same thing, large dark center and coal falling off the edges. Didn't run much today because it was warm, but I think I'll start tomorrow at 5 teeth and 5 air and see what happens.

The bin has about a ton of coal that was sitting outside in barrels for the last 10-15 years. I don't know if that's the problem or not, but I have a good feeling about running at 5 teeth tomorrow.

stoker-man wrote:The bin has about a ton of coal that was sitting outside in barrels for the last 10-15 years. I don't know if that's the problem or not, but I have a good feeling about running at 5 teeth tomorrow.

Buy one bag of new Blaschak to fill the pot with. Once it catches, it should burn the older stuff too.