harmon pf100 room temp sensor accuracy

[mdoble]

My pf100 temp sensor is way out of whack; setting 63 results in a room temp of around 71 deg. I know that offsetting the service heat setting on the control panel can adjust this offset somewhat (3 deg) but I want to get it right.

When adj so that the room temp matches the dial setting (loosen set screw, re-index the knob) the potentiometer range is so biased that I can only lower the temp to 65 deg


I would like to be able to set back the room temp to 60 but the answer I get from the dealer is that "they all do that" (have inaccurate sensors)

Does your pf100's temp sensor share this "feature"?


'gards,

Malcolm

 

[phasterone]

I am new to pellet stoves and I am running my P68; rather the stove is running itself for me. Where is your temp sensor located? I have mine 6" above the floor, 6"away from the wall, near the back of the stove (6") so it is basically getting return air temperature. Temperature of my 24' x 48' room's midpoint is right on the money according to my fuel oil furnace thermostat readout 25 feet away from the pellet stove. My setpoint is 70F room is 70F, my setpoint is 60F my room is 60F. No more oil for me ever again.

 

[Rattlesnake]

Had to reset my thermostat dial a bit as it was about 5 degrees off, however, it now works ok. When the furnace reaches a certain temp it turns down the flame and after a while on low flame, if the thermostat still does not require more heat, it has turned itself off. I have not really timed it, but seems like it is around an hour of not requiring heat.

 

[mdoble]

Rattlesnake - was it off in the same direction as mine?

(before adj actual room temp higher than indicated target temp)?

Malcolm

 

[Rattlesnake]

Yes, when you set the dial at 60, room temp was a little under 65. Now it is 65/65.

 

[propanevictim]

I'll chime in here. My thermostat has been off from day one. 65 degrees is actually 70. Same deal with adjusting the knob/set screw. Can't turn the knob down all the way, but that shouldn't matter really. Should still be able to get down to 60. In my case, I can't now turn the knob to the maximum temperature--which I wouldn't do anyway. 70 degrees is good for me. I haven't played around with adjusting the temp. setting on the unit itself yet.

 

[fiddlesticks]

Brand new to the PF100. After getting the duckwork...venting...etc, I cranked it up tonight. I think I am having the same problem with the thermastat. Not sure I understand the best way to solve. One more try?

Thanks

 

[Crash]

My temp dial is set at 2 on the furnace (per dealer). Wall control pointer is set just past the 0 of 70 and I get a temp of 71 on all thermostats in the house. Seems close enough for me.

 

[fiddlesticks]

Thanks. How many square feet are you heating, and what setting do you put the feed adjuster on?

 

[Crash]

I have 1700 sq foot living area. It's a old, ugly 3 story house though. The pellets I have now(hardwood) I run the feed rate at 2.5. When I had Pro-Pellets I had it set at 3. With the cold coming Sun. -12, it should get one heck of a workout.

 

[Rattlesnake]

For what this is worth. My dealer initially set my feed rate to 3, and blower speed at medium and said leave it there. He also said I did not need to draw from my existing cold air ducting, just take it from the basement air. However, when at their shop to pick up some pellets, and talking to another employee (who seemed to have more knowledge of the unit), he told me to try some changes, said it was more economical to hook into the cold air ducts, in order to reheat within an enclosed system. That made sense, so I did it. He said that the feed rate knob on the PF100 is actually a limiting switch for the highest feed rate allowed. He recommended that the setting be increased to 4.5 or 5, as it will allow longer feed rates in the beginning, leading to quicker warmup and higher burn rate when it is needed. Once that is accomplished, he stated the furnace will automatically cut back the feed rate to what the stove needs to keep the set temp. He also recommended the circulation fan be switched to low, as it would be more efficient in moving the warm air thru the ductwork in the house. I followed his instructions, so far, he seems to be correct.

Again, I'm just learning along with all the other new buyers so don't shoot the messenger.

 

[Crash]

Thanks Rattlesnake, I think I'll give it a try setting the feed rate higher, it does make sense. As for the blower I stayed with the normal 1000 cfm, medium setting seems to do pretty well. Heck this is all new to me, I switched from burning wood to this, so far the wife and I really enjoy the steady temp the house stays at.

 

[Rattlesnake]

Crash: I really wish they would put out a manual that actually describes in detail what each knob and switch does. However, it looks like trial and error for now. I also installed an outside air supply, but can't see that it made much of a difference. Good luck.....

 

[hossthehermit]

I tuned the pellet furnace to run well. Switched to tstat control, now just slide the slider to where the house is at the warmth I want. If I'm cold, I slide it up, the house gets warmer. If I'm cold, I slide it down, the house gets cooler. The whole number game just don't work for me.

 

[fiddlesticks]

Interestingly, I had to take back the circuit board of my PF100. the furnace wasn't lighting and was feeding to point overflowing the burnpot even when not burning. Since then I have learned a little. First, the dipswitches were set incorrectly at the factory on the original board. Also, vent and draft probably has something to do with the richness of the burn which I fear I am burning to much. I have about a 16 foot horizontal which is just inside spec per the book...and then about 12 feet vertical to give it some draft. I am heating a 2500 sq ft home...old mid-1800s so not so tight. I am dealing with damper issues in the duct work with the old oil system and hope to have those straightened out tomorrow as the damper going into the oil furnace isn't closing when the PF100 kicks on.

I got the latest circuit board which seems to be much more accurate with the temperature control from the thermastat...the new board doesn't have the big chip on it, but a much smaller integrated one. It is good to about 1 or 2 degrees by my estimates.

The feed rate is set at 4 as the manual says...the dealer said I may want to try increasing the combustion fan speed to increase draft to help burn more efficiently. I also did not caulk the vent pipe on the furnace collar. Bottom line is I am burning around 3 to 4 bags per day (although it is very cold out). I also see some visable smoke coming out of the vent pipe outside. I assumed I would be burning less than that and would like any ideas on thoughts to reduce burn (while keeping heat). I also bought thte 1500 fpm fan per the suggestion of the dealer.

Thanks for any ideas.