I won't speak to the operation of the Kaa2, because I don't have one and uncharateristically I won't offer an opinion....oliver power wrote:I'll give you my settings. First off, I'm heating 1700 square feet using 76 feet of 3/4" finned baseboard radiation. I'm heating my place to 73*. So, unless you have a big heat loss, the little Kaa-2 is not too small to heat your 900 square foot house. I'm burning buck size coal. Stoker feed: turn the feed screw all the way clockwise. Then back it off about 3 - 3-1/2 turns. Triple Aquastat: is set 160* Low - 180* high, w/10 differential. Timer: with these temps, I need 3 groups of 5 pins. Being only 900 square feet, 5 pins per group may trigger your high limit aquastat. Then you'll try 3 groups of 4 pins. Maybe add / subtract one or two pins. You get the picture? With the Kaa-2 boiler, you need to maintain a higher, more responsive fire on the carpet. And you do this with timer pins, depending on weather conditions. The Kaa-2 is not engineered to run on the timer, but that's how it has to be run. That's what throws the non-Kaa-2 owners off. On other boilers, the timer is for keeping min fire. As for the Kaa-2, the bigger the fire, the less lag time, which gives the stoker time to ramp up, and take over in these bitter cold temps. If the carpet fire is too big, you'll trip the high limit aquastat. Take out pins to fine tune. Too much lag time, and the boiler drops below the low limit on the triple aquastat, shutting down the circulator, which if I'm reading into this correctly, is your problem. Yes, if you hear water going through the pipes, I too am guessing the noise is air. I'm guessing your problems are; 1.) not enough pins in the timer. 2.) Air in the system. 3.) Too much heat loss. 4.) As Sting said, slowing down the flow gives time for heat to be absorbed by the finned baseboard radiation. Let us know how you make out. Oliver
however, as to the rest of this post:
http://www.homedepot.com/catalog/pdfImages/14/14f ... 9a77fc.pdf
page 8 gives the btuh of 1ft 3/4 inch slant fin tubing. So lets say that you're working your Kaa2 to the max and deliveryin 200f water to the radiators, your heat output total is going to be
810 (btuh per ft) X 76(lin ft radiation) = 61560 btuh into the dwelling.
That's it. Doesn't matter if theres a small fan blowing on the boiler ( ), all you get is that amount of heat.
If you look at the chart, you'll see they list btuh in two rows, one at 1gpm, one at 4 gpm. And the 4gpm output is higher than the 1gpm. That's because of this bit that I ran across after posting some unfortunate comments about system balance, then deciding that maybe I should go back and figure out what it was:
http://www.caleffi.us/en_US/caleffi/Details/Magaz ... s_8_us.pdf
In that rather long book you'll find this bit:
The flow rate through each heat emitter also affects its
heat output. The following principles will always apply:
• The faster a heated fluid passes through a heat
emitter, the greater the rate of heat transfer, when all
other conditions are equal.
• From the standpoint of heat transfer only, there is
no such thing as flow moving too fast through a heat
Some heating professionals instinctively disagree with
the second principle. They argue that because the water
moves through the heat emitter at a higher speed, it has
less time in which to release its heat. However, the time
a given water molecule stays inside the heat emitter is
irrelevant in a system with a circulating fluid.
The increased heat output at higher flow rates is the
result of improved convection between the fluid and
the interior wetted surfaces of the heat emitter. The
faster the fluid moves, the thinner the fluid boundary
layer between the inside surface of the heat emitter
and the bulk of the fluid stream. The thickness of this
boundary layer determines the resistance to heat flow.
The thinner the boundary layer, the greater the rate of
Another way of justifying this principle is to consider the
average water temperature in the heat emitter at various
flow rates. Consider the example shown in figure 2-2
where water at 180ºF enters the coil of an air handler unit
at different flow rates.
As the flow rate through the coil increases, the temperature
difference between its inlet and outlet decreases. This
means that the average water temperature in the coil
increases, and so does its heat output. This holds true
for all other hydronic heat emitters, such as radiant panel
circuits, panel radiators and baseboard.It might seem intuitive to assume that heat transfer from
a heat emitter increases in proportion to flow rate through
it (i.e., doubling the flow rate through the heat emitter
would double its heat output). However, this is not true.
So, faster flow rate, once the boiler reaches the high limit will deliver more BTU to the dwelling. What we don't know is if the circulator is running continuously, or shutting off.
Finally, there's this:
http://www.builditsolar.com/References/Calculator ... atLoss.htm
Insert a 30by30 house, 9 foot walls, 136 sq ft of windows and doors with two occupants, and minimal insulation and you'll end up losing ~47kbtu hour at 0deg f. Rough, but absent more details it serves to illustrate what the OP is up against trying to heat his dwelling.