Harman PF100 operation troubleshooting

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nateschisler

Member
Apr 8, 2011
40
Central OH
Ok...just finished my PF100 install...working on a detailed install post for everybody. Fired it up yesterday and wow...awesome...

So...before I assume I have a hardware problem, let me see if I understand the operations of this unit correctly. As many have stated, the manual leaves quite a bit to be desired. I am running my unit on manual (automatic with manual-lite).

The thermostat controls the feed motor. Turn the thermostat set point above the ambient, feed motor ramps up to the setting you have selected, consequently heat output ramps up, and the fan/limit control kicks on the distribution blower. The blower is not controlled by the thermostat...which is why you don't hear the typical "click" when the setpoint is reached. Am I understanding this correctly?

Also...is it possible the thermostat could be off by 3-5 degrees? Ambient was 74 (based on my other thermostat), Harman thermostat was at 70 and calling for heat.

One last question...when the unit is "idling" (below the thermo setpoint) what is the consumption rate? Manual says 1 lb. per hour...is this close to correct?

Thanks...
 
distribution blower controlled by plenum sensor.

thermostat usually off by a few degrees....loosen set screw and adjust accordingly if you like, or just rememebr the differential and run with it.

on idle,I'd say closer to 1.5 lb/hr, but in the end, its governed by the exhaust temp, so it will do what it thinks to be correct low burn temp.
 
Thanks Delta...

So with my thermo calling for heat and my feed rate set at "1", I burned through a bag in 12 hours. Flame was noticeably smaller than with the feed rate at "4"...but nowhere near what it sounds like the idle rate is. So sounds like I haven't hit the "idle" feed rate yet b/c of the thermo differential.
 
just so we can be on the same page...what is your "feed adjuster" knob set to? It should be 4ish, that knob will not control the size of the flame the way one would assume. If you have the other knob (the one that says "normal" instead of #4) set to 1, then the unit will be at low burn...still governed by the temp at the ESP probe.
 
I am currently running with the "normal" knob at "normal" and the feed adjuster at 1. When I was at "normal" and "4" and with my thermo at 72ish, it took my ambient up to 77...so I dialed down the feed rate.

I was originally under the assumption that the distribution blower was controlled by the thermo and was thinking I had a bad thermostat or bad connection. Now it sounds like my thermo is just several degrees off when compared to the digital one for my A/C. So it has contantly been calling for heat and I choked it down with the feed rate.
 
definitley put the feed adjuster to 4 and leave it there pretty much forever...turn up a bit if you have very large pellets or down a bit if you have teenie tiny pellets. In manual mode the 1-7 knob with control the actuall combustion rate. Is it counter intuative? yes, but thats how it works. go figure.
 
I does and doesn't. It limits the maximum amount of Lbs of pellets an hour you burn. If you don't need the heat to keep up with your heat loss the computer tells the furnace to lower the feed rate.
 
If using the Therm, one of those needs to be on 3 not 4, I can't think which it is except it's not the feed rate one. I keep the feed rate at 3. I hear 3600sqft with about 1/3 of that being an unfinished basement. I go through 2 - 2.25 bags a day while keeping the main floor at 70. Basement is about 65-67 and upstairs is 67 - 68
 
I had a similar problem when i first installed my pf100, and took notes. First of all it sounds like your thrermostat needs adjusting. However these thermasates that come with the the stoves take alittle while to figure out and are very touchy. when my stove is set to 70 degree's it will heat the room up to 71. Now the furnace itself will go back to a minimum burn. Now minimum burn is where the feed adjust rate comes into play. If you have your stove set on feed rate 1, then minimum burn will have a smaller flame then if you have your feet rate set to 4. minimum burn will continue to burn and blow warm air into your home as long as the thermostat calls for heat to be around 70 degrees (the actual setting) at a consistent rate. Now if the thermostat stays on the set temp for a certain rate of time without dropping ( i still haven't figured out the time frame yet) then the stove will shut down, and NOT turn back on until the ambient temp of the house reaches 3 degrees below the thermostat setting.

The other knob (with the "normal setting") is for using the furnace as a free standing furncace without a thermostat. You turn the knob higher and it gets warmer, you turn the knob lower and it gets cooler. The only time that the thermostat is operational is when it is on "normal setting" So if had that knob set to anything but "normal setting" you were bypassing your thermostat, and that would have been giving your inside temp higher or lower then your thermostat setting.
 
P.S. I live near winston-salem NC, the climate here doesn't get all that cold, and my feed adjust rate is at number 1 all the time. Heats my house well at minumum burn. Its a complete waste of wood pellets to run that rate any higher then it needs to be. On a cold day if you home stays at a consistent temp that you prefer, then thats all you need (regardless what the books suggest, notice that the book is a "suggestion" and not an absolute) Now if minmum rate isn't doing it for you, then kick the rate higher till you find your solution. The entire system is simple once you understand it, but it is really complex to explain to just let me know if i didn't do a good enough job explaining.
 
When a constant cold out, my unit is on manual after start and the thermal set for the house to be at 70. I have never in all the time its running see the temp move off 70. I love the pf100
 
What would be cool is if someone who knows the operational flow of these PF100's post one long post here basically outlining the operational flow of these things in auto and manual....something the Harman manual really fails to do.

Info that tells what the stove does on its own from light up and what effect the controls have on what and the theory behind their operation.

I'd be glad to do it, but just getting mine in October.....I'm still guessing.
 
archie79 said:
P.S. I live near winston-salem NC, the climate here doesn't get all that cold, and my feed adjust rate is at number 1 all the time. Heats my house well at minumum burn. Its a complete waste of wood pellets to run that rate any higher then it needs to be. On a cold day if you home stays at a consistent temp that you prefer, then thats all you need (regardless what the books suggest, notice that the book is a "suggestion" and not an absolute) Now if minmum rate isn't doing it for you, then kick the rate higher till you find your solution. The entire system is simple once you understand it, but it is really complex to explain to just let me know if i didn't do a good enough job explaining.
I tried turning my feedrate down to 1 from 4 today. Temp outside today arounf 40. Went to the movies this afternoon and came home a few hours later. Felt the house getting cold and checked the digital thermometer. Was 63. Went down and checked the furnace. Stone cold out with a 6 light blink on the status light. Increased it to 2. I'll see what that does.
 
Oh six blinks is in the install manual as being a blocked flue or air inlet. If the furnace can't breath it can't function. Did you check the pressure in the flue when you installed the furnace? It's a pretty easy test. All you need is a manometer there are several YouTube vids showing you how to build on for a few dollars. ( that was the way I went). How did you venilate your stove, and did you use the outside air intake?
 
Furnace was installed by a certified tech and he did all the checks of the flue. Was running OK until I changed the feedrate to 1 from 4.
 
Well the furnace shouldn't have completely went out with a feed rate at 1. Hmm is the furnace in a confined space or a small room? Also, do you live in a state that pellet stoves are pretty popular?
 
Installed in a large basement. Yes there are a lot of pellet stoves in New England.
 
Somewhere in the system it's starving for air and judging by a larger flam not going out, I would say that the problem is on the exhaust side of things. Did they go up a flue or through a wall? Sounds like something is stopping up the exhaust somewhere.
 
I restarted the furnace over an hour ago and it has been running fine Since. There are no blockages anywhere.
 
The only other explanation is that the 1 setting isn't a larg enough flame to keep your house at the desired temp. So I guess the flame heats the heat exchanger the the blower turns on and cools the heat exchanger to quickly to keep your house at desired temp so instead of just running all the time blowing cool air it just shuts down instead? However, if that was the case you would think that would be in the trouble shooting section somewhere. It would be nice if Harmon offered customer assistance. But I also have to admit that I like puzzles.
 
OK PF100 and PB105 furnace burners....
"Have a Happy New Years"
We always hope that the coming year is better than the last,
so lets hope for the best.
 
Red Devil said:
OK PF100 and PB105 furnace burners....
"Have a Happy New Years"
We always hope that the coming year is better than the last,
so lets hope for the best.
Thanks and the same to you and yours!
 
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