Stove off but motor keeps cycling on

[dogugotw]

Harmon XXV.
If I'm on room temp mode and turn down the temp so I can clean, the stove burns out the current wood load and then shuts down.

If I just wait, I'll hear the stove briefly make that little 'rrrr' noise when the fan turns on, then it stops. The fans never spool fully up; it's on for less than a second, more like 1/2 sec with some lasting maybe a second. The stove doesn't light but it just sits there going 'rrr rr rrrrrrr rr rrrr'

I had at least one case where the stove seemed to stay on when the room was plenty warm.

I called the dealer and their service guy suggested that the room temp sensor might be bad. Swapped it out, problem remains.

The stove runs great in stove mode but I prefer room temp mode as I think I burn less wood.

Anything I can try/test before I call in a service visit?

Thanks in advance for any tips.

Doug

 

[PJPellet]

Try cleaning the exhaust esp probe. If it's clean, it could be the probe itself(defective). I would start by cleaning the esp exhaust probe though.

 

[dogugotw]

I just checked the manual and see where the probe is but the only advice is 'don't break it'. Is this thing especially sensitive? Any specific way I should or should not do the cleaning?

As long as I'm pulling pipe today, I think I'll just go ahead and do a full up clean.

Thanks for the assist.

Doug

 

[lbcynya]

I just checked the manual and see where the probe is but the only advice is 'don't break it'. Is this thing especially sensitive? Any specific way I should or should not do the cleaning?

As long as I'm pulling pipe today, I think I'll just go ahead and do a full up clean.

Thanks for the assist.

Doug

(Harman... )

Just remove the screw and pull it straight out (not by the wires). Should be pretty snug so you'll need reasonable force. Didn't seem that fragile to me.

Pull pipe? Don't need to remove any pipe to get at the ESP...

If you know how to read ohms, the resistance for the ESP should be in the 35 to 45 range (from PJ's other thread). Anything dramatically different would suggest the probe is trash. How many seasons have you run the stove?

 

[dogugotw]

Har-mon, like Jamaica-mon... ;-)

The diagram in the owner's manual shows the probe as you'd see it looking from the back into the exhaust port and make it look like it's mounted to the outlet pipe. I'm guessing from your statement that I've misinterpreted the diagram.

Since you say I don't need to pull the stove pipe, does that mean that I can get to it with the back skins off?

Thanks.

Doug

ps - visited Mr. Google and found an entire cleaning procedure with cool pictures and something I may just buy...that rail kit would make getting behind the stove SO FREAKING EASY!

http://www.google.com/url?sa=t&rct=...HQ5rM-tHkQziWkfPw&sig2=FrXcVe9yEbmpL9vcKChOSg

 

[lbcynya]

Har-mon, like Jamaica-mon... ;-)

The diagram in the owner's manual shows the probe as you'd see it looking from the back into the exhaust port and make it look like it's mounted to the outlet pipe. I'm guessing from your statement that I've misinterpreted the diagram.

Since you say I don't need to pull the stove pipe, does that mean that I can get to it with the back skins off?

Thanks.

Doug

Ya-mon, just take de right rear skin off (opposite control board side). You'll see the red (maybe black) thin wire running to the top of it. Remove attachment screw and pull the probe straight up while gently twisting. More crud on the probe the harder it will be to remove.

 

[dogugotw]

Out of sync here...see my previous post - found a very detailed procedure. Man I love the web!

It's for a different model, but the innards look about the same.

 

[dogugotw]

Found and cleaned the esp probe along with the rest of the stove and the chimney. I'm not sure if the problem is resolved yet. It didn't make the noise, then it did, now it's not (*)...I need to run for a bit to see if it stays or goes away.

Question - the room temp sensor has a red and black wire. Is the thermistor polarized and if so, what happens if you plug the thing in backward? Does it break anything?

Thanks.

(*) If the sensor is polarized, this may be my problem. I've had it in both ways today and one way seemed to generate the rr noise while the other didn't. I tried swapping leads before and it didn't seem to matter but that was before I cleaned the stove. Maybe I should just call the service guy and quit pretending to be Mr. Fixit...

 

[76brian]

No, the sensor is not polarized. Doesn't matter which way it goes in.

 

[subsailor]

Harmon XXV.
If I'm on room temp mode and turn down the temp so I can clean, the stove burns out the current wood load and then shuts down.

If I just wait, I'll hear the stove briefly make that little 'rrrr' noise when the fan turns on, then it stops. The fans never spool fully up; it's on for less than a second, more like 1/2 sec with some lasting maybe a second. The stove doesn't light but it just sits there going 'rrr rr rrrrrrr rr rrrr'

I had at least one case where the stove seemed to stay on when the room was plenty warm.

I called the dealer and their service guy suggested that the room temp sensor might be bad. Swapped it out, problem remains.

The stove runs great in stove mode but I prefer room temp mode as I think I burn less wood.

Anything I can try/test before I call in a service visit?

Thanks in advance for any tips.

Doug

I'm surprised you think the room temp mode uses less pellets. From my experience, the stove gets close to the setpoint, then the distribition fan shuts down and you just get radiant heat. It's not bad early fall/late spring, but when it's cold out, it keeps cycling. I prefer the stove temp mode.

 

[subsailor]

By the way, it's HARMAN.

 

[dogugotw]

By the way, it's HARMAN.

See my 9:55 am post

 

[dogugotw]

No, the sensor is not polarized. Doesn't matter which way it goes in.

OK, that's good. In that case, I'm going to withhold judgement for a bit to see if the thing is actually fixed. I am very glad to know that there is no foul if you swap the wires. Thanks.

 

[dogugotw]

I'm surprised you think the room temp mode uses less pellets. From my experience, the stove gets close to the setpoint, then the distribition fan shuts down and you just get radiant heat. It's not bad early fall/late spring, but when it's cold out, it keeps cycling. I prefer the stove temp mode.

And you are probably right. I guess I'm thinking about pellet use when it's still fall and I don't want the thing running all the time. While I was having trouble with the thing not shutting down properly, we were in a warmish spell and I'm relatively sure that stove temp mode was using more pellets than if we were in room temp mode. Given that our day temps were 30 - 45 (and occasionally up to 60!) I would have expected to use about 1/2 bag a day max and we were using about 1/day.

Once temps drop below freezing and stay there, it pretty much stays on anyway so use rates may be the same or lower with stove temp. At night we tend to let the house go cold so the stove will go off for periods of up to an hour or so before kicking back on.

Some time I'll need to just experiment and see if I can measure any difference in use based on mode.

Thanks.

Doug