CB1200 i convection blower

[shorehaman]

Hi everyone,

I have been running my Quadrafire cb 1200i 24/7 since just before Christmas and it has run like a charm. I have treated it very carefully and have cleaned it as recommended in the manual faithfully - maybe even more so since I clean the firepot everyday and I have vacuumed the firebox every other day. I remove the baffles and clean the heat exchangers and exhaust duct after every ton. Yesterday I gave it the 2nd ton cleaning.

This morning I noticed that the convection blower was cycling off and on about every 20 minutes or so. The thermostat call light stays on and the augur continues to feed the firepot which continues to burn nicely. Everrything looks normal except the convection blower shuts down and then comes back on a little later. I have checked my manual and have also looked at my quad DVD for information, but I am not sure how to proceed.

I understand that the convection motor is controlled by the snapdisk # 1. Therefore I assume that this snapdisk is malfunctioning and opening for some reason.

Does any one have a suggestion how I might evaluate this further?

 

[ldjlookalike]

If you can remove the snapdisk hold it to a regular 100 watt bulb to test. Should get hot enough.

 

[slls]

You have a 2 year warranty parts and labor if bought new.

 

[shorehaman]

Thanks guys for your quick response.

My stove is new and I will contact the dealer for service, but I am always curious about these type of issues and like to troubleshoot when I can as long as I don't get in over my head. So I was exploring and looking for a solution in case the dealer response is slow.

I have not sought to remove the snapdisk since I wasn't sure if it was a simple task. As I understand it, Snapdisk # 1 is connected by two purple wires which I can see when I open the left side panel door. Is the snapdisk the small disk shaped component that the wires connect to? If I turn the power off and disconnect the wires, can I remove the snapdisk by removing the two screws that attach it to the body frame?

 

[shorehaman]

Hi again to everyone,

I just wanted to give you my current status and seek further feed-back.

I decided to not remove the snapdisk since I really wasn't sure what I was doing at this point. However, I was curious what would happen if I ran the feeder and convection blower on high rather than on medium. After I switched the heat output to high, I found that the unit ran as if nothing was wrong. On medium it would only run for 10 - 15 minutes before it would stop blowing (auger feed and fire would continue to run just fine with convection blower off.) On high the appliance ran all afternoon long without the the convection blower shutting down.

This performance led me to think that perhaps I had inadvertently lowered my feed-rate control rod when I had cleaned the hopper the previous day. (I recall a pellet that had lodged between the frame and the feed-stick which I forced out with my firepot scraper).

I pulled the control rod further out about 1/2" and the system ran fine with my heat output switch on medium.

I conclude that with the reduced feed-rate that the fire temperature as monitored by the thermocouple was enough to keep the auger feeding the firepot, but not enough to maintain the appliance temperature as monitored by by snapdisk 1 when the convection blower came on. Increasing the feed-rate was the solution.

Does this make sense?

 

[LJ Smith]

Did you figure out what the problem was? I'm having a problem similar to yours. My CB 1200 runs fine on high, but on med or low the convection blower stops. Anyone know why this would happen? Is it a bad switch?

 

[shorehaman]

Hi - After I increased the fuel flow rate slightly by pulling the feed rod out, I never had another problem. The stove has run absolutely normally since then.

My interpretation (which I don't fully trust) is that there wan't enoug heat produced in the firepot to keep the stove interior above the setpoint established by snapdisk1 when the convection blower came on. Hence the cylcing off and on of the blower. Once I increased the fuel available the problem went away.

I do welcome other opinions.

Shorehaman

 

[Jim Jules]

Hi. I'm new to this forum, but know things about the control box and wire harness on the 1200-insert and some of the other quadrafire pellet stoves. It sounds like the snap disk isn't getting hot enough to keep the convection motor running. I wish I could tell you what temperature it's set point is. You can bypass snap disk #1 by taking the purple wires off and jumping them together. I would use a wire with 1/4" male quick connects on each side. This is for troubleshooting purposes only, because the convection motor will stay running as long as the stove is plugged in. The convection motor will change speeds with the burn rate switch. If at any time the convection motor stops when the stove is plugged in (thermostat can be on or off), it's the motor, the control box or the harness. I hope it's lack of heat to the snap disk. Maybe you can find a normally open snap disk with a lower temperature set point.

 

[LJ Smith]

Thanks for the reply. I had checked (jumped) the snap disks. I will try it again because it's been a while since I tried to troubleshoot. I have to think that it is a problem with the 3 position switch though. The convection immediately stops when the switch is moved from high to med. or low. There is no delay for a temperature decrease before the convection blower shuts down. Hopefully it's just the switch and not the control box.

 

[Jim Jules]

Hi LJ Smith.
The 3 way switch (burn rate switch) is wired to the control box on pins 2, 4 and 6. The 3 way switch controls the auger feed rate, the combustion motor and the convection motor. If the combustion motor changes speed and/or the feed rate changes when you flip the 3 way switch, then the switch is good. I've done allot of troubleshooting on control boxes. It sounds like the convection motor is bad. Usually when the control box goes bad the triac circuit will short out and the motor will stay on high (115v) when you change the 3 way switch. I know it sounds crazy, but you can swap the purple convection wire with the blue combustion wire on the fans and see if the problem moves to the combustion motor. If it does then there's a good chance its the control box.

I forgot to ask you if you if you had a 2 way switch next to the 3 way switch in the stove. The older 1200 stoves had a "turbo" switch that went to 2 different windings on the convection motor. Is your control box gray or clear? The gray control boxes are getting old and the clear boxes are replacing them. The triac circuit for the motors are stronger in the clear control boxes. I can get control boxes for good price. They come with a 1 year warranty.