AHS-130 Flapper Problem

I would check the fan to vessel space setting. Loosen the shaft so you can slide it in and out to find out where it is in relation with the face of the boiler. If it moves in a considerable distance before it hits, that is your problem. Not sure about the AHS, but the AAs will move about 1/2-3/4 of an inch. Reset it about an 1/8" or so off the boilers face (spin it by hand until it stops scraping, back it up from there, tighten, realign your pulleys) and see if that flapper slams for you.

coaledsweat wrote:I would check the fan to vessel space setting. Loosen the shaft so you can slide it in and out to find out where it is in relation with the face of the boiler. If it moves in a considerable distance before it hits, that is your problem. Not sure about the AHS, but the AAs will move about 1/2-3/4 of an inch. Reset it about an 1/8" or so off the boilers face (spin it by hand until it stops scraping, back it up from there, tighten, realign your pulleys) and see if that flapper slams for you.

Done all that and the 1/8" does draw more air, as I tried it on my boiler.

AA130FIREMAN wrote:
Easy fix, have you son move back home with you Another thought, does the flapper door swing freely and how far away is it. My AA uses a threaded bolt and 2 nuts on either side to keep the flapper away at idol, some times it would hang up on the threads if it was too close to the inner nut. If AHS uses the same cutting edge technology as the AA

No thanks on the son moving back. Flapper is free, the most puzzling thing is even when I try to hold it in place, nothing.

Perhaps there is a manufacturing defect that creates an air leak.

I suggest this because you have established that the fan provides proper air flow yet an air flow is not created at the shutter valve sufficient to close it.

Your initial description suggests that air is NOT being drawn up through the coal in the firepot--" I fired her up last week and after 2 days she died ". Therefore it appears the air has to be coming from somewhere else. The fact that the flapper is not pulled closed seems to demonstrate the air is not coming from the port covered by the shutter valve. There is no where else for the air to come from in a AHS boiler that is correctly constructed.

Perhaps you could identify the problem by removing all coal and ash and then removing the grate and inspecting the firepot from below. The other alternative would be to return the unit to AHS for inspection/repair.

Gismo said: I have a AA 130 but they are simular.The space between the bottom of the fire pot
and the ash tray regulates max air flow.When you fill the pot it creates a vacuum pulling
the draft breaker door shut.

Put everything back together, filled the pot with ash turned it on an BAM the flapper shut tight, never did that in the 2 years I had her before. My eye is now on the thermocouple and the fuji controller, maybe over shaking but no unburnt coals. Grate on temp is set at 130. Got to take out the manual. Any tricks to these controllers. Whats the resistance on the thermocoupler for testing, does anybody know?

Mazzy

I am sure this sounds waco,but most of my problems are caused by
turning the ash temp.DOWN to low.This causes the fire to get to thin,
even though you get no unbernt coal,they run better with a thicker fire
which is what I get when I run a hotter ash setting(like 140 Deg.)

If it was overshaking that much wouldn't you lose your fire? Doesn't make a whole lot of sense does it?

gizmo wrote:I am sure this sounds waco,but most of my problems are caused by
turning the ash temp.DOWN to low.This causes the fire to get to thin,
even though you get no unbernt coal,they run better with a thicker fire
which is what I get when I run a hotter ash setting(like 140 Deg.)

I will second that, I was tring to lower the temp of the asher, and now I seem to have better ashes, finer with less clinkers, when I adjust the temp up, only do 3 degrees a day and wait for the change. Small steps are better than great leaps.

jmmazzy wrote:. Whats the resistance on the thermocoupler for testing, does anybody know?

Mazzy

As you say the temperature sensor on the ash controller is a thermocouple. It's a welded joint of two dissimilar metals. Resistance will be very low, too low to measure with any common VOM. Perhaps you were thinking of a thermistor, a device that changes resistance with temperature. In the HVAC industry a common thermistor has a resistance of 10K ohms at room temperature. Your AHS thermocouple should show a short when measured with a common meter.

Started her up. Lowered grate temp. to 120 as recommended by AHS manual for warm weather conditions and will increase it as the outdoor temps drop,seams to be running excellent. Checked thermocouple with my fluke thermometer, reading accurate on the fuji controller. Dumped heat and cycled stoker 5 or 6 times, seems to be working fine, flapper doing nicely. I'm beginning to believe that all my testing should have been done with the fire pot filled with more ash as I put 2 one gallon buckets in on top of what was already there, and there was a lot. I will take a vaccumn test tomorrow through the sight hole on the flapper (thanks gizmo) and report back.


Mazzy

...and a DC voltage (millivolts) when the end is heated

Done the draft test on son's stoker, -1.0 inches of mercury and seems fine, fan set 1/8" from back plate.
Done the draft test on my stoker, -2.0 inches of mercury and never had a problem. fan set 5/8" from back plate direct from AHS.
When there is a good load calling when its real cold out my stoker rumbles almost like an oil boiler.
Being that the blower fan is actualy an induced draft fan at the fire pot any problem would have to be at the fire pot, the opening at the antratube, hopper, cone, or the fan itself. After spending many hours on these units they do look identical to each other inside and out.
So what I'm getting at is because of the differance in draft (air) we know one will burn more than the other, more fuel on the fire more BTU's. Does anybody know or have any idea how to do a efficency test to a AHS stoker using this method to get the max. rated BUT's?

Mazzy

jmmazzy wrote: Does anybody know or have any idea how to do a efficency test to a AHS stoker using this method to get the max. rated BUT's?

Mazzy

In a closed loop hydronic heating system the circulator pump characteristic flow curve can be used to compute flow. In effect the pump becomes a flow meter. You measure the pressure differential across the pump with a pressure gauge at the inlet and outlet of the pump. The pressure difference is a measure of the piping resistance (pipe head) and gives you the operating point on the manufactures pump curve. You then read the flow (GPM) from the curve. Next you measure the boiler supply and return water temperatures. Then you have what you need to calculate BTU's delivered per unit time, i.e., BTU/hr.
This equation is only an approximation because it assumes the water temperature is 60 deg F. Clearly in a boiler test it is not. A more accurate equation adds a term for the density of water at the higher temperature.

For common residential circulators and piping systems the pressure difference across the circulator is only a few psi. You need a differential pressure gauge, for example, like those sold by Dwyer. To select a gauge you re-plot the pump curve in psi rather than feet of head. It's important to select a gauge that has sufficient resolution.

Thank Yanche, but I haven't used those formulars since I was an apprentice Local #77 Plumbers & Pipefitters now Local #51. and I'm retired now if that tells something. Remember I Have 2 systems, both with primary loops and don't plan on cutting into them, do the calucations and trying to do the stoker ajustments all at once, I'll be there for a while. What I am looking for is at some point in time AHS & Axman Anderson tested there units and came up with a BTU rating. To do this they needed to calculate how much draft (air) they needed to fire over that fire pot. How did they measure it?, static pressure, vaccumn, or something else an how. All this should tell us where the induced combustion fan should be ajusted at and take the appropriate reading for ajustment. It's like an oil burner and nossel that is sellected for a particulare boiler, nossel, air band, sutter ect. I can't get this from AHS, all I get is ajust the fan like this is plug & play. All us antratube owners should have this info.

Mazzy

Hi,I was just wondering if you figure you have to many btu,s or are you short
on output.Everything I do to mine is to try and tame the monster down.Its
way big for my heat load in two seperate buildings + domestic hot water.The
only time I look at draft is when its not running, waiting for a heat call,thats
is when the draft steals heat from me.

jmmazzy wrote:Thank Yanche, but ... What I am looking for is at some point in time AHS & Axman Anderson tested there units and came up with a BTU rating. To do this they needed to calculate how much draft (air) they needed to fire over that fire pot. How did they measure it?, static pressure, vaccumn, or something else an how. All this should tell us where the induced combustion fan should be ajusted at and take the appropriate reading for ajustment. It's like an oil burner and nossel that is sellected for a particulare boiler, nossel, air band, sutter ect. I can't get this from AHS, all I get is ajust the fan like this is plug & play. All us antratube owners should have this info.

Mazzy

Here's the reference to the AA test report I transcribed and posted almost 5 years ago:

Bureau of Mines Report 4936 Axeman-Andersen Anthratube Boiler

It's a history book of instruments used way before the start of my engineering life. It shows all the test methods they used.