Cab 50 stops feeding pellets when high speed fan starts

[Bradcole1827]

I've got a Heatilator CAB 50 in my basement. I've been unable to find my specific problem in the forum. The stove seems to work fine on the low and medium settings. However, on the high setting, it stops feeding pellets the moment the high speed fan engages. If I start it on the high setting, it will light, burn, function fine, heat up, but then as soon as it gets hot enough to trigger the high speed blower fan, the fan turns on, the pellets stop feeding, fire goes out, and I have to reset it to start it again. After reading many threads, I've tried the following already:

• Clean everything thoroughly.
• Took off Thermocouple ceramic cover, cleaned, put it back on and made sure the TC was pushed tight against the inside of cover.
• Varied the feed gate in all different positions.
• Took all duct work off and cleaned
• brushed out burn pot. Never get clunkers.
• Did the $ bill test. No leaks.
• Opened a basement window to ensure there was no lack of air.

It's got to be a sensor of some sort, I believe. I'm out of ideas. Any suggestions? Thanks!

 

[Mt Bob]

If you do not have to manually reset any of the snap switches you probably have a bad board.

 

[SmokeyTheBear]

Sounds like you are getting a high limit trip, when stoves overheat they can act in a number of different ways, however the one thing they do in common is stop feeding pellets.

On stoves with automatic reset high limit systems nothing has to be reset as soon as the stove gets cool enough they can be started up and they will run.

On stoves with manual reset requirements when the stove stops due to overheating there is a button that has to be pressed before you can restart the stove.

I don't have a CAB manual in front of me so I don't know how your stove will operate when it is overheated.

What does the manual for your stove say about high temperature (over-fired operation).

 

[Mt Bob]

Sounds like you are getting a high limit trip, when stoves overheat they can act in a number of different ways, however the one thing they do in common is stop feeding pellets.

On stoves with automatic reset high limit systems nothing has to be reset as soon as the stove gets cool enough they can be started up and they will run.

On stoves with manual reset requirements when the stove stops due to overheating there is a button that has to be pressed before you can restart the stove.

I don't have a CAB manual in front of me so I don't know how your stove will operate when it is overheated.

What does the manual for your stove say about high temperature (over-fired operation).

Looked it up for him,is a manual reset.

 

[SmokeyTheBear]

Looked it up for him,is a manual reset.

bob,


There are 2 safeties on that CAB 50 that deal with over heating, over-fire, burn back. Snap disc #2 (fuel feed interrupter) which is auto reset on cool down and snap disc #3 (burn back, over fire) which is supposed to be manual reset.

Both of these will stop pellet flow, the other things that will stop pellet flow are reaching the t-stat setting red call light will be off and the vacuum switch.

I did a quick online read of the October issue of the manual, I don't have any manuals on my machine, they are on backup. I got a new system earlier in the year and I haven't reloaded a lot of stuff. Was busy playing with making the system into a media server for the new TV. My music, photo, and a large part of my DVD collection can be streamed to the TV.

 

[Mt Bob]

Cool I learned something today.That has got to be great to have all that on a server,got to make life simplier.

 

[Mt Bob]

Smokey I took another look at the october combination manual again and it says both 2&3 are push to reset.I see op did not reply so we may never know.

 

[SmokeyTheBear]

Smokey I took another look at the october combination manual again and it says both 2&3 are push to reset.I see op did not reply so we may never know.

The other thing that happens over time and with improper stove maintenance is the convection blower can stop and the stove go into over temp. It also possible for the combustion blower to overheat and stop leading to loss of "vacuum".

If you change the feed re-stricter (aka flame height) you also have to wait for the change to take full effect and to make the change only on high fire (or you could find yourself going over temp a couple of minutes after going to high fire).

As for the switches I like manual reset anyway for such a case. Nothing like a full stop to get one's attention.

I also trust the factory to install the correct parts (Yup, sure I do. Hey where are the sarcasm tags).

 

[saladdin]

I've got a Heatilator CAB 50 in my basement. I've been unable to find my specific problem in the forum. The stove seems to work fine on the low and medium settings. However, on the high setting, it stops feeding pellets the moment the high speed fan engages. If I start it on the high setting, it will light, burn, function fine, heat up, but then as soon as it gets hot enough to trigger the high speed blower fan, the fan turns on, the pellets stop feeding, fire goes out, and I have to reset it to start it again. After reading many threads, I've tried the following already:

• Clean everything thoroughly.
• Took off Thermocouple ceramic cover, cleaned, put it back on and made sure the TC was pushed tight against the inside of cover.
• Varied the feed gate in all different positions.
• Took all duct work off and cleaned
• brushed out burn pot. Never get clunkers.
• Did the $ bill test. No leaks.
• Opened a basement window to ensure there was no lack of air.

It's got to be a sensor of some sort, I believe. I'm out of ideas. Any suggestions? Thanks!

Figure out the problem?

 

[smwilliamson]

I'm gonna say blocked flue. Vac switch is rolling out when more pressure is created in firebox

 

[Bradcole1827]

SOLVED!

Guys,

Thanks so much for all the input. I feel bad for not responding sooner. I hadn't given it much thought over the summer.

So the answer was.... Intake air restriction.

After total frustration, I decided to start inspecting all the air passages.

Turns out, I had a clump of ash jammed in the air intake. How in the h**l did that happen? My best guess is that upon pulling out the ash pan to clean, the clump tumbled out the low, back side of the pan, and landed right in the air intake.

Then maybe it got jammed farther in upon pushing the ash pan back into place. I'm guessing about 1/3 of the rectangular intake duct was blocked.

When I used an air compressor to shoot air inside of the intake duct (intending to just get dust out), the brick 'o ash popped out as if I gave it the Heimlich maneuver.

So there it is. I keep my stove pretty clean (apparently except for that strange anomaly), so I thought it was something else, but it was just a clunker in the air intake.

Once I got that "clunker" out of the intake, I fired it up and it is working good as New!

So I think smwilliamson was onto it. It was starved for air and the vacuum switch caused it to cut out out upon calling for more air.

At least that's my amateur diagnosis.

Regardless, I'm now enjoying a fully functional stove again!

Thanks for the input from all! Appreciate it all!

 

[JFLY]

I have the same problem now.. I shut the stove down to clean it quickly. Started it back up and now it shuts down as soon as the blower comes on. Confused? The two manual resets did not appear to pop as you cant' push back in. I cleaned the flu and checked the air in-take.

 

[kappel15]

Try jumping the wires on snap disc #2 to see if it fixes it. Could be a bad disc. If that don't work, try jumping the vac switch wires. kap