P68 Room Temp Lock-Up

[apn73]

Hello,
Anybody ever notice with their Harman that the temperature will lock-up in room temp mode? I generally run between the 70 and 75 degrees on the temperature selector, but sometimes when I back it down to 70 it seems to be locked 75 and continues to fire hard. I've had to shut the stove off a couple of times to get it to reset. Anybody else seeing this or am imagining it?
Thanks,
Adam.

 

[Bioburner]

How old of stove? Just checking as pot switches fail but usual problem is with the fan control switch. New problem that I have not heard of before.

 

[F4jock]

Hello,
Anybody ever notice with their Harman that the temperature will lock-up in room temp mode? I generally run between the 70 and 75 degrees on the temperature selector, but sometimes when I back it down to 70 it seems to be locked 75 and continues to fire hard. I've had to shut the stove off a couple of times to get it to reset. Anybody else seeing this or am imagining it?
Thanks,
Adam.

Clean the ESP. If no joy check the Room Temp Sensor wires and replace the sensor if need be.

Have you tried the Ice Cube Test on the sensor when it locks?

 

[apn73]

How old of stove? Just checking as pot switches fail but usual problem is with the fan control switch. New problem that I have not heard of before.

Stove is a 2013, so pretty new.

 

[apn73]

Clean the ESP. If no joy check the Room Temp Sensor wires and replace the sensor if need be.

Have you tried the Ice Cube Test on the sensor when it locks?

I didn't know about the ice cube trick, I assume that the ice cube will make it fire at maximum. With the weather the way it's been, I'm sure that the ESP will get touched until closer to spring. I've been firing it in room temp manual for the vast majority of the time, so not sure if a lot maintenance burning will make a difference or not.

 

[F4jock]

I didn't know about the ice cube trick, I assume that the ice cube will make it fire at maximum. With the weather the way it's been, I'm sure that the ESP will get touched until closer to spring. I've been firing it in room temp manual for the vast majority of the time, so not sure if a lot maintenance burning will make a difference or not.

You don't have an alternate heat source so you can clean the ESP?

 

[apn73]

You don't have an alternate heat source so you can clean the ESP?

I do, but time is not something that I have a lot of these days. If we get out of this cycle of heavy snow every other day and bitter cold, then maybe I can take it down on a Saturday.

 

[F4jock]

I do, but time is not something that I have a lot of these days. If we get out of this cycle of heavy snow every other day and bitter cold, then maybe I can take it down on a Saturday.

Needs to be done. That and the ice cube / fist wrap test on the room temp sensor.

 

[bags]

I'd say the ESP needs to be brushed off. Likely has build up by this time of the heating season.

 

[apn73]

I'd say the ESP needs to be brushed off. Likely has build up by this time of the heating season.

If I'm seeing it in the manual correctly, the ESP probe is accessible through the ash door, on the back wall, through the little door, do I have this right?

 

[Bioburner]

May be able to view a youtube clip on cleaning a Harman to get a good idea before poking and possibly bending the probe. They are about $70

 

[bags]

Yes the ESP probe is thru the ash door behind the removed ash pan. Then there is a latch that should rotate up and to the right letting you remove the exhaust hole plate. Get a flash light and it is up in the exhaust a little ways. You need a longer parts brush or small paint brush with additional handle reach and you can gently brush the ash build up off.

Second option is taking the right side panel off and removing a screw holding it in and gently pulling it out. You can clean it better this way but not needed if you brush it off from the front without removal.

unplug! your stove FIRST if you go diving in.

Do as BIO suggests and look for the video. It is easy but get to know what you are doing.

 

[apn73]

Well thanks everyone for the help, I'll check out youtube before I go probing around in there.

 

[bags]

Is your stove new?

 

[apn73]

Is your stove new?

Yes, 2013, but it actually didn't get installed and used until 2014. It's been running hard since October, cleaned (well, everything except the ESP) about every two weeks which is when the ash has to be removed. It's been flawless except for this issue, and the burnt plastic smell coming out the vent from the GS pellets (got a thread going on that over in the pellet forum). Funny, this issue has gone away over the last couple of days, but I'm still going to clean the ESP over the weekend.

 

[bags]

I started running mine Oct 18th and it's new. The ESP does get ash coated. I've cleaned mine several times already and it runs like new still. It better! Burning some funky pellets may add to your ESP not being clean.

Since it has gone away the ash build up could have blown off or whatever but you should clean it after every ton burned to eliminate problems. It is very easy and quick to do. A stove this age you shouldn't have any issues and the pot switches should not be worn. I'd bet money it is a cleaning issue.

 

[apn73]

I started running mine Oct 18th and it's new. The ESP does get ash coated. I've cleaned mine several times already and it runs like new still. It better! Burning some funky pellets may add to your ESP not being clean.

Since it has gone away the ash build up could have blown off or whatever but you should clean it after every ton burned to eliminate problems. It is very easy and quick to do. A stove this age you shouldn't have any issues and the pot switches should not be worn. I'd bet money it is a cleaning issue.

I wondered if the pellet problem has contributed to the ESP issues, but I'm sure it needs to be cleaned regardless. One thing I did was turn the temp selector down to 60, let it idle down, and then set it back up to 70, been fine since. It made me wonder if there is deadband between 70 and 75, but ESP should still be cleaned.

When you guys first said to clean the ESP I was thinking that I was going to need to access it from the back and that I was going to have take apart the vent, which wouldn't be fun with the snow, cold and wind we've been having lately. I was very relieved to find out that was tucked in behind that access port in front of ash pan.

 

[bags]

It is easy to get to from either place really. No need to disconnect vent at all. Did you find the video on Youtube? What are you running in mode wise. Room Temp auto or manual? Feed rate? What settings is your stove in?

 

[apn73]

I haven't looked around on youtube yet, but stove cleaning is tomorrow's task. I run in room temp mode and manual on the igniter the vast majority of the time. Feed rate in the 3 to 3.5 range, temp is usually in the 70 to 75 area, sometimes 80 if the place is cold.

 

[bags]

These are about the same exact settings I run. Yesterday (Sat.) and today it warmed up some and I will switch it up to a very low maintenance burn of feed rate 1.5 - 2, Constant burn or stove mode with dist. blower on high as usual, temp dial on 2, and flip into auto on the igniter so the dist. blower runs.

This keeps the cooler edge knocked off and maintains a nice inside temp. This can vary slightly with what the outside temp might be.

Today I am going to do a good clean since I will be heading out of town for work. That way it is good to go for the Mrs.

 

[bogieb]

Yes, 2013, but it actually didn't get installed and used until 2014. It's been running hard since October, cleaned (well, everything except the ESP) about every two weeks which is when the ash has to be removed. It's been flawless except for this issue, and the burnt plastic smell coming out the vent from the GS pellets (got a thread going on that over in the pellet forum). Funny, this issue has gone away over the last couple of days, but I'm still going to clean the ESP over the weekend.

If you have been running since October, I would think that you not only need to clean the ESP - but also clean the exhaust pathway behind (which I gather hasn't been done since you didn't know the location of the ESP).

Every time I empty the ash pan, I remove the rear door and clean the fan and gently run a brush thru the channel past the ESP and then use a crevice tool on my vacuum to get out ash knocked off.. Every 5-6 weeks I run a brush from the opposite end; I don't have to worry about the ESP the since the brush won't make it past the 45 coming off the stove. I then vacuum it from the inside as my crevice tool will just make it to that 45.

I know all about having to empty the ash pan every two weeks. The Currans that I got are so ashy, that I have that issue too. Last year I could go 3-4 weeks as pellet quality was better. Hoepfully next year's pellets burn cleaner!

 

[bags]

Be sure to clean the fines box and igniter area too.