Looking for Help With a New KAA-4-1 Boiler Install

Hi folks,

After deliberating for over the past year on what type of heat source and boiler model to choose I finally went with Keystoker and the kaa-4-1 dual fuel model. Lots of thanks to this forum for helping to steer me in the right direction even if I was just a lurker at the time. So now that the boiler is resting in my basement I thought I would take this day to establish my profile and preemptively look for help on my upcoming project. You all might be wondering why I waited until winter to do the install...easy answer...I thought my oil boiler would make it another year (it didn't) and a little bit of apathy. So before I purchase most of the copper fittings tomorrow I was curious to know if it would be wrong to install the circulator on the return side but have the pressure tank on the supply side. The following pic shows the existing boiler that is getting removed. It now leaks several gallons a day. You'll notice the heat exchanger hooked up on the return side. This is for an outdoor wood boiler that I stopped using after last season. I am still on the fence whether I will plumb this back into the system.
This next photo shows my chimney connection. Currently a 6" pipe going into a 10" crock. I am wondering if it is standard practice to install coal boiler stove pipe the same as an oil boiler. In other words...can I put the 6" boiler pipe into the larger crock and seal up the difference with furnace cement and bricks? And if so should I extend the stove pipe all the way to where the chimney flue starts? I could not find a product anywhere that would transition between the two sizes. Here is a better horizontal view of the top of the existing boiler and the older gravity fed piping that runs the perimeter of the house. The last photo shows the stripped down kaa4 as it sits currently in my basement. We had to use my front end loader and a tow strap to get this thing in the basement. I ordered this boiler from Martin's Produce in Shippensburg who gave me a very good price, about a $1000 less than the other quotes. I am thankful for any help you folks are willing to give. I am looking to start the install Tuesday morning and be done by wed evening. I am hoping the plumbing supply in my area carries all the 1.25" copper fittings I will need...if not I will have to go through an online store and wait a few more days for delivery.

Cheers,
Rod

Welcome.

I would remove that heat exchanger. Once you get the KAA-4 running you will want no part of that wood boiler. Might as well put the wood boiler on Craigslist NOW and get it sold.

Is your house just one zone? Since you are re-piping it anyway, I would put the circulator on the supply side, pumping away from the expansion tank. Also put a ball valve and boiler drain on the return, that way you can easily purge the loop of air.

Do not forget the 1" bypass piping between the supply and return header. You will see it noted in the Keystoker manual - it keeps the temperature in the boiler uniform when it is idling.

Thanks Rob!

I think you are right about the OWB. I just put in a wood stove in our laundry room so I think that should take care of my wood cutting habit! The OWB was way too much work for WAY to little efficiency. 15 cords a year on average.

Our house is 1 zone with cast iron radiators. Since we have the radiators I can just purge air from each one so probably wont need that on the return side. I will be putting the bypass in but was thinking of putting a 1" ball valve on the loop so I can fine tune it if need be. My big source of confusion is why the factory recommends putting the hi limit probe on the bypass loop. Wouldn't you want it in the boiler itself? They certainly have enough 3/4" access points.

When the boiler sits idle, the hottest water will flow through the bypass loop. You could mount the 4006B on the boiler itself if you wanted, but Keystoker's recommendation works well.

Yes, put a ball valve in the bypass pipe so you can tune it.

I called Keystoker before plumbing mine and they recommended putting the triple aqustat in the middle port and the high limit aqustat in the port closest to the chimney end. See SF-260 to KAA-4 for my short install thread. I put an outfire aquastat in the port closest to the stoker but have not hooked it up. It idles perfectly so I may never hook it up. Mine is parallel with an existing oil boiler. Keystoker may recommend a different set up for the dual fuel. You should call them to chat. Just tell whoever answers the phone that you have a few questions on your KAA-4

Good afternoon Rodmo1,

I also have a Keystoker KAA-4-1 with a used Reillo Mectron 40 OIl burner with the hydraulic lift jack for the air intake for the combustion chamber that we took out of the Buderus Logana G205 boiler that it replaced.

I know its late but please invest in two paper backs -Classic Hydronics and Pumping Away which were written by Dan Holohan. Dan writes all his books for the plumber and the layman alike and explains everything in detail. They are very easy to read and understand as he makes reading them fun as he also explains his working in the plumbing business and the HVAC industry and the history of heating and cooling in these books and the other ones he has written.

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After putting up with the Hydrostat 3250 Plus digital controls and the Voodoo-
Voodah is the proper pronunciation; I have a horizontal L81241011 in the left tapping and a separate B+G Bulldog RB-122-E low water cut off in the right tapping as you are facing the
fire door and the ash pit if you have them on the left side-as you stand behind the
hopper while looking at the hopper.

How are your radiators plumbed bottom to bottom or otherwise?

Once you get your KAA-4-1 boiler running the lower operating temperatures that I use will be more than enough with all the thermal mass you have using the radiators you have now.

You should also invest in several cans of Fernox boiler treatment as it is a new boiler and each aerosol can treats only so much water.

I will be more than happy to help you as I have been put through the mill by lousy plumbers and the digital controls that failed to work properly and as a result my boiler almost blew up my house due to the digital controls not working. I also kicked the second set of digital controls sent as replacements when the Low Water Cut Off function on the second unit 8shut it self off while I was testing it while running the boiler on oil this spring.

I had enough!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

The Hydrostat 3250 Plus triple aquastat is ment for a cold start oil or gas boiler.

Keystoker has had fifty plus of these things returned and the two I and the bad gauges have will be going back.

The Honeywell L81241011 Triple Aquastat with the properly sized thermocouple probe well has been flawless in its performance.

The B+G RB-122-E Low Water Cut Off is wired so it shuts off all the power to the boiler in the event of a low water condition. The RB-122-E has a wet contact sensor that protects the boiler.

What ever you do do not depend on the round four inch gauge supplied with the boiler.
you cannot even find the name of the gauge manufacturer in China on the box!!!!!!!!!!!!!!!!!!!!!!!

Spend the money on a Marshalltown triple gauge for your boiler and a Honeywell L8124A they are worth every penny and operate properly and accurately. You can buy the the triple gauge from the local ACI controls sales office in your area or from a plumbing supply house that carries them in stock. I received mine in two business days after I placed the order.

I purchased my honey well L8124L1011 triple aquastat and a spare from Patriot Supply and the Bulldog low water cut off from a local B+G retailer near me.

I also had to have new wiring as the Horizontal L81241011 and the Bulldog low water cut off required more work to wire it but It has not overheated nor have I had an outfire since I started burning this year.

I found out the boiler was not working when It overheated slightly as he timer motor was dead and I purchased a replacement timer motor locally for less than $30.00.

I have my boiler set with:

150 high limit 120 low limit with 15 degrees differential on the L81241011

The L6006A is mounted on its own well in the steam chest by the Domestic Hot Water Coil
is set at 180 degrees. Your unit should have the L6006A with its propelry sized well in the ash baskets that they supplied with the boiler.

I have my hot water pumping away off the large tapping in the steam chest to feed my single zone and I have plenty of heat available at the lower hot water operating temperatures in the boiler and I just turn up the thermostat when its colder-like today.

I also have a 15 gallon Steel expansion tank hung in the ceiling above the boiler.

I purchased a sheet of 1,000 degree high temperature fiberglass furnace insulation for the boiler top from Mcmaster Carr as I needed to keep the heat in the boiler. I am glad I invested in the insulation. The oil/gas will be very noisy when operating due to the size of the combustion chamber in the KAA-4-1but after a while you do not give it a second thought.

My boiler bypass line is piped to the lower left tapping of the boiler which is also used for the cool water return line. My boiler bypass line is controlled with a B+G flow control valve to open and shut the bypass line.

I have kept very detailed records on the boiler and its operation as well as The plumbing parts I purchased for it to save money. I purchased almost 95 percent of the steel and copper pipe fittings for the installation as well.

I also have a pressure and temperature gauge in the cool water return line that enter at the left tapping in the boiler sump.

As far as the stove pipe/flue pipe; I have 6 inch 24 gauge black stove pipe:

1. I have a 6 inch tee coming right off the flue breech with 6 inch plug cap to let the fly ash drop out that will accumulate.

2. the tee connects to a short piece of straight stove pipe that also connects to a second Tee that has the Barometric damper-its easier to use a 6 inch tee than cut the stove pipe, after that there is a 6 inch elbow that connects to a third Tee that has a 6 inch plug in it to clean out the fly ash that will accumulate there.

3. after that my stove pipe rises and connects to a 7 to 6 inch reducer in the clay thimble and then exits to the block chimney.

One thing to be aware of is that the KAA-4-1 and probably the other dual fuel units as well have
a baffle box that is welded to the flue breech and the flue gasses passes through an opening on the bottom of the flue gas baffle that is 1 inch wide and 6 inches long and probably longer on the 8 inch flue units.

The oil burner baffle plate stays in the firebox the year round and you have to be careful not to knock it loose when cleaning as you have to be inside the ash pit to get it to hang right the first time.

The other thing is that you have to be sure the oil/gas burner tube does not enter the firebox as the heat from the coal fire will destroy the burner tube and you will need to replace it.

I have had my Intermatic 30 minute timer set with 8 pins(2 minutes at zero time and 9 pins(2 minutes 15 seconds at 15 minutes on the timer and it has worked flawlessly after I replaced the timer motor that went bad.

In my stoker I have one inch of ash, 3 inches of fire in a heat call, with 3 inches of unburned coal
and a one inch plus hold fire when it is operating to keep the fire going.

I have my stoker set with 9 threads out after the initial fire start up and I have not had an outfire since I replaced the timer motor.

I also wire numbered and lettered "all" the wiring runs to make sure that every thing was connected properly and can be found in the event of an electrical problem.

The wiring diagrams are very poor in the Keystoker manual and they have a draftsman making new ones as they are leaving the boiler electrical drawing as the last drawings to be done. I offered to help them but I guess they were not interested in my help.

Be sure to invest in 2 sets of 1/2 inch unions for the Domestic hot water coil as one set is not enough and my plumbers screwed that up too but it will be fixed when the time comes.

Please be sure to hang the copper oil line or lines from the from your tank on the ceiling to keep them out of the way and use longer braided oil lines to let you lower the burner to the floor when you need to change over to oil. Be sure to pack the insulation in tightly in the burner tube to keep the oil or gas nozzle from fouling when switching from oil to coal.

With my lower temperatures I am using about 80 pounds of rice coal a day and I have three extra ash baskets so that I can change them out when they are half full with less work.

Do not hesitate to send me a PM if needed and I am only a phone call away if you would like to talk.

We only want to help you and see you succeed just like the members helped me and I have a warm house and a happy spouse finally.

Happy plumbing.

lzaharis wrote:The Hydrostat 3250 Plus triple aquastat is ment for a cold start oil or gas boiler.

Some of us are having good results with 3250's on coal boilers.

This is great! This forum sure makes up for Keystokers bare bones install guide. It looks like I will be installing the hi limit on the boiler itself then. A couple less fittings and should make for a cleaner looking install.

So...as of now I am looking at having a direct return run with just one main ball valve and the tee for the bypass loop.

On the supply side it will go bypass tee > air scoop/expansion tank > ball valve > pump > ball valve > flow check valve

I may just connect the water fill to the supply side instead of the boiler itself.

lzaharis states to use standard 24 gauge stove pipe. That is what I was planning but was curious of the physical connection between the stove pipe and the boiler. Currently there are no holes drilled to attach the two with screws. Are people just inserting the pipe in the outlet until tight? I would much prefer a physical connection.

I am disappointed to hear all the troubles with the 3250 aquastat. I travel a lot in the winter and am really hoping this thing is super dependable when I am out of town. Perhaps we will upgrade sooner rather then later.

My radiators are plumbed on the bottom of each side and each one has its own valve. Here is a picture of one I disconnected for some carpeting installation. Another issue I am worried about is hopper fires. Of course I will check my draft and ensure that the cement is sealing the burn grates. The issue is my basement is only 6' tall at the beams and any fire has the real potential of catching the floorboards and beams since they will only be a foot or so above the hopper. I don't know what a hopper fire looks like but it sure sounds alarming!

Cheers,
Rod

You could step that 10" thimble down to 6" with two reducers. If you don't want to deal with that, you could hook it up like it is now...or mortor in a 6" thimble.

In my opinion the issues with that 3250 control are exaggerated. I have installed 4 of them and they are all working fine.

The makeup water should be piped to a tee on the bottom of the air scoop, just above the expansion tank.

no big deal on the flue outlet, get a couple big self tapping screws.

Rod,
My 3250 has worked perfectly since it was installed in April. I ran all summer for DHW and never had any issues at all. I used Duravent stovepipe and it just slips over the flue outlet on the stove. Some people drill a hole through the pipe and flue outlet and insert a nail or screw for extra safety but I have not. Mine is sandwiched between the stove and chimney. I was concerned about hopper fires too until I let it run out of coal before cleaning it in September. No issues at all with just a few pounds of coal in the hopper. Just always make sure the burner plates are cemented correctly at each cleaning.

As I am sitting here putting my parts list together I got thinking that maybe I should use some sort of dielectric union for the steel to copper connections. Does anyone recommend using a brass nipple on the inlets and outlets of the boiler case? I am not sure what code is here but most people online seem to hate the mechanical dielectric unions due to leaks but in some cases a brass fitting is allowed instead.

Rod

A hopper fire can be detected by controls and then cut off the power to the whole unit is that is desirable???

Okay...I made it successfully through the first install day. I got the old boiler out and the new boiler in and plumbed. Started running new copper before I gave up around 9 PM.

A couple issues I discovered:

1. 2 out of the 3 aquastat holes are right up against the domestic coil. I see 2 problems with this. I think it will end up giving a false reading when we are running the hot water also when I tighten in the well it ends up rubbing against the coil. I believe this may trip the low water limit sensor. The third hole is too far left and the mounting will not work with the oil gun there.

2. Since the supply line comes off a 1.25" or so downtube into the boiler tank. If you do not install the expansion tank per manufacturers suggestions you will wind up with a significant air pocket. I still plan on putting in a downline airscoop/expansion tank but now I will need to open the relief valve to bleed off the excess air when I fill the system.

I should have this thing running tonight tomorrow at the latest. Just in time to with this cold weather coming. Negative wind chills the next few days. Also...I changed my design again due to space constraints. Now I plan on putting the pump on the return side with 2 valves for easy replacement. On supply side I will have air scoop/expansion and then flochek valve then main valve.

Rod

We are going to need some progress pictures!

Put a float vent in the top of the boiler, or a boiler drain (useful for bleeding air and venting while draining).

It is common to have the aquastat well close to the coil to reduce lag time. Mount it in the closest one that doesn't cause interference.