A couple Austroflamm Integra V1 questions?

[skibumm100]

I have been running my 1995 Austroflamm Integra V1 for a little over a week and I’m noticing that my room convection fan speed continuously varies. The combustion appears to be pretty stable and the auger feed timing is stable. I read the manual and it appears the convection fan speed is controlled only by the power knob setting on the operator control panel. At first I thought the air flow sensor may have been giving a less-than-stable output but it appears that the air flow reading only adjusts the combustion fan speed. The convection fan speed varies at all power settings. Has anybody ever seen this happen before? My stove is running on EPROM V2.4.
This stove is a heat monster. I also have been considering connecting a thermostat to the stove to help regulate the room temperature. The manual shows the terminals to connect the thermostat as 7 & 8 on the terminal strip. It also mentions the EPROM V2.5, V2.5A and V3.1 are designed especially for use with a thermostat due to a convection fan delay feature. I’m not sure why that would matter. Does anybody run a thermostat on the V2.4 EPROM with good success?

 

[Mark_ms]

As you said your convection fan is controlled by the knob on the control panel by the on/off switch. Your setting dictates how fast or slow your air comes into the room, which also adjusts feed rate and combustion fan
Once I set mine it is constant and does not vary, unless I change the convection fan speed.
I do not have a thermostat, my wife thinks it is one more thing to break (but I'm working on it)

 

[skibumm100]

Thanks Mark,

That's what I gather from the manual. It's almost like the fan is surging. I will need to poke around and see if I can figure out what's going on. It seemed worse last evening although it's been doing it some since start up. Could be a power level bad pot but I would think that would affect everything. Maybe it is and I just can't tell. I may put my voltmeter on the connections at the convection fan tonight. Pretty easy to reach while the stove is running.

 

[Mt Bob]

Hey mark what version prom are you running?Skibumm all 3 motors controlled by air flow sensor.My old unit still running eprom 2.3.It does what yours does,has since new.My understanding is the newer eproms do this less,and newer air flow sensor may help also.Mine is in basement,so only notice when down there.If you took the time(have to have the side cover off)the combustion blower always changes speed 1 to 2 minuites before convection,but only slightly.I think this is one of the fixes in the updated eproms,but cannot get any answers from people that sell them.Also,if you have an original board,the age on the capacitors can affect this also.Hope this helps.

 

[Flammam]

My stove has the same surging of the convection blower. Been doing it for close to 20 years with no problems. I think I'm running ver. 2.1?

 

[Mark_ms]

Bob,
I am pretty sure that is the 2.5 version, it was upgraded when I had circuit board rebuilt a few winters go.
I will try to determine the exact version for you at some point.

 

[Mt Bob]

Bob,
I am pretty sure that is the 2.5 version, it was upgraded when I had circuit board rebuilt a few winters go.
I will try to determine the exact version for you at some point.

A lot of times the rebuilders automaticly reflash/upgrade the eprom as part of the price,might say on your invoice.You know what the sad part is?Twenty year old stoves still running,and biggest complaint is this problem,and you have to be almost sitting next to it to notice?They built these old ones well!

 

[Mark_ms]

A lot of times the rebuilders automaticly reflash/upgrade the eprom as part of the price,might say on your invoice.You know what the sad part is?Twenty year old stoves still running,and biggest complaint is this problem,and you have to be almost sitting next to it to notice?They built these old ones well!

We all need to get a life

 

[skibumm100]

It wouldn't be a problem if it was farther than 5 feet away. I checked the voltage with a meter and it does vary up to 5 VAC. I suspect it may vary even more as it was surging more yesterday but I was too lazy to get the meter out. I'm glad to hear mine's not the only one and I will now stop worrying and have a beer. I thought it may be possible that I was overheating my air flow sensor. My inlet air has been a s high as 130 deg F when I've checked it. The air flow sensor is temperature compensated but I'm not sure what the maximum temperature is. I guess I'll find out......

 

[Mt Bob]

I have cleaned sensor and made a slight difference.You will never overheat the sensor unless stove is on fire the way it is not supposed to be.Well got to go out and plow more snow.

 

[skibumm100]

I have my venting and OAK set up to preheat the combustion air and I'm connected right to the combustion air intake, no gap in back, so it gets pretty hot. I'm not sure what the air flow sensor was designed for but I suspect it can get to 150 deg F or higher if the stove is cranking on high.Fortunately, I don't usually need to run it that hard. My combustion air intake is basically a 10 foot long counter flow heat exchanger. It's a 4 inch rigid pellet vent inside an 8 inch insulated prefab fireplace flue. Combustion air is drawn down the old insulated fireplace flue along the outside of the 4 inch pellet vent.

 

[Mt Bob]

I have my venting and OAK set up to preheat the combustion air and I'm connected right to the combustion air intake, no gap in back, so it gets pretty hot. I'm not sure what the air flow sensor was designed for but I suspect it can get to 150 deg F or higher if the stove is cranking on high.Fortunately, I don't usually need to run it that hard. My combustion air intake is basically a 10 foot long counter flow heat exchanger. It's a 4 inch rigid pellet vent inside an 8 inch insulated prefab fireplace flue. Combustion air is drawn down the old insulated fireplace flue along the outside of the 4 inch pellet vent.

I doubt if it would ever get that hot.If you could measure the outside temp. on the exhaust you would probably be suprised.Just recently I was woundering why nobody makes a silicon gasket for the combustion blower,only one stove maker,so I took the side off the stove and did temp checks.At low setting the temp averaged 155 right around the blower.On high for an hour the temp at the blower was 300-to 350,while around it was 500 to 580.Airflow keeps the motor and mounting flange cool.At any time you could put your hand on the insulated pipe before it goes into the chimney after the first 90

 

[skibumm100]

Next time I run it on a higher setting I'll log some temps. I have seen flue gas temps in the high 300's (like 380's on high). That's measured with a type K thermocouple in the flex pipe after the cleanout tee so that's the flue gas temp. That's firing pretty hard. I believe the type K eading more than an IR gun as the emmisivity setting of the gun is probably off for flat black steel.

 

[Mt Bob]

I was concerned with temps at the gasket surface.K's are great for instream but as a user of non contact for over 30 years I know what to expect.Also internal pipe temp.is not what your air intake will see.

 

[skibumm100]

IR's not bad if you know what you're doing and are aware of it's limitations. I see quite few cheap one's that are great for laser cat toys, but not much else. I have an older Raytek that has adjustable emissivity but was almost $900 when new. The prices have come way down but they don't seem to have the features anymore. You're correct that the temperature on the outside of the pellet flue is not the same as the flue gas temp. The pellet vent is double wall so there is some insulation there. It's a good thing, too, or it would get really, really hot on high fire. Today it's just loafing along as it was 40 degrees out.

 

[wwert]

I believe there is a capacitor that controls the fan and makes sure it gets constant voltage. Sounds like yours is shot. The latest EPROM is 3.5 I believe

 

[semipro]

I just got my new old (2009 model) Integra going and experienced the issue with the varying convection fan speed right away.
I believe the problem is due to something called hysteresis which has to do with lags in changes of things like sensors temps and how the control circuit compensates for these lags.
On my my stove I can adjust the convection fan speed via the LED control panel from 100 to 150% speed. The fan speed still varies but the fan runs somewhat faster over its whole range of operation. I sat and monitored the fan speed allowing time for it to stabilize and found that I could minimize the fan speed "hunting" if I set mine to 130%.
Perhaps there is a CF fan speed control on older units that accomplishes the same thing?

Edit: after monitoring the fan speed more I noticed that it gets faster when a bunch of pellets enter the burn pot at one once rather than in a steady stream, which would make sense as the fire increases, more heat is produced, temps go up, and the temp sensor and control board respond by speeding up the fan. So some variation in convection fan speed is inevitable if the fuel supply rate to the burn pot varies.

 

[skibumm100]

Hi semipro. My Integra doesn't have a temperature sensor. It has an air flow sensor in the intake pipe. The only adjustment, besides the trim pots for fuel and combustion air, is a dial on the control panel. The dial tells the main board to increase or decrease the fuel and air. It's an open loop control, no feed back.