Distribution blower on PC45 won't come on

[Findyourwayhere]

Hi folks. Just installed a used PC45, burning corn. No room sensing probe installed so am running in stove temp mode. Have tried all the combinations of settings I have seen suggested in the manual, in various threads, etc, and can't get the distribution fan to come on. (It comes on in Test mode so I know it works.)

My understanding is that I should set the stove temp dial to L and the temperature dial to 80-90, and the fan should come on as soon as the stove has reached a certain temperature. But it's just not coming on.

I am still figuring out this stove (obviously) but if anybody can help me out a bit that would be awesome. Thanks.

EDIT: Let me add a thermodynamics question -- am I losing heat/efficiency if the stove is not pushing out heat via the distribution blower? I saw a thread where someone suggested I would be because more heat would be going out the exhaust, but my sense is that is marginal and that while the distribution fan gets the heat into the room quicker, it mostly all radiates out to the room eventually, right? I am using the stove to supplement a natural gas furnace so as long as I am not wasting heat by not running the distribution blower, I may not care...

 

[Lake Girl]

Welcome to the forum! The distribution blower also keeps the stove body cooler so without the blower running there is a high likelihood you will get an over-temp situation that will shut the stove down.

Have you cleaned the ESP probe? Beyond that, you will have to wait for the other Harman owners to chime in...

 

[bogieb]

Have you tried the stove temp on H? Also, do you get a good flame or does it seem to stay small? In stove temp mode it shouldn't matter that you don't have the probe, but I've heard a couple of stories where it di for some strange reason. If the flame is staying small, then your ESP may not be getting hot enough for the distribution blower to come on.

Also, are you in manual or auto? If in manual, try flipping to auto - that will tell the stove to run the distribution fan regardless of exhaust temp.

Without the distribution blower going, a lot of the heat is going out your exhaust - not the ideal situation.

Keep in mind that I don't have a P45, and assume it runs much the same as the other P-series.

 

[jp99]

Check your mode switch like bobleb suggests - in Manual, the PC45 is like a fireplace, just makes a fire for you to watch unless the temperature is quite high (then the fan only runs to cool the stove). In Automatic, the distribution fan will turn on once the stove warms up enough to put out heat. This is the most likely cause unless you have an actual fault in the controller board.

Regarding the other question - if the dist fan isn't running, you are dumping heat out the exhaust. Now, if you define efficiency in this case as how much heat you put into your home and extract out of the fuel vs the total energy input, then yes you are running with a very low efficiency. The radiant heat energy off the stove surfaces is significant but still missing a large amount compared to forced convection via the distribution blower. If you could extract every bit of heat out of the unit so the exhaust temperature is the same as the cold air inlet temperature, then you'd have 100% efficiency. That's not something you can thermodynamically achieve.

So you can't get that in real life, but I have read a well tuned and operating PC45 can be as high as 85% efficient. Given the low effluent temperature out the exhaust, that might be in the right range. Although I'm a thermal engineer (electronics cooling), I don't usually calculate my stove efficiencies.

If someone really wants it done I suppose I could do it with some help - I'd need to know the feed rate of the fuel in terms of energy. That's the hard to find unknown - it would take a test (in X minutes how many pounds of pellets are fed - how much energy is that - and finally if the stove feeds at a some duty rate - say 30% - how much energy enters the stove per unit time).

Then the lost heat is calculated from the inlet and exhaust temperatures, and the air flow rate, for the given stove feed rate. Those two (input energy rate, and lost energy rate) would be simplest parameters to measure/calculate to find the stove efficiency.

In my earlier career I did some energy balance calculations on an operating nuclear power plant - same process for a pellet stove, just a little bit smaller scale

An IR image of my PC45:



And one of my exhaust stack:

 

[bogieb]

Wicked cool (or hot) pics!

 

[bags]

Nice pellet porn pics there. I am pretty sure you need your room sensing probe plugged into your stove for it to operate correctly regardless of the mode you are running. They are pretty cheap and easily found on the net at various pellet stove parts suppliers and / or a dealer. Buy one and plug it in.

The 45's are a bit more finicky on when the Dist. Blower kicks on vs. some newer P Series stoves. They need to get up to temp before it will kick on but yours should be if you are running your stove and in test mode it works. These are smart stoves and not having something not hooked up that is supposed to be there results in goofy performance and things not working like they normally should.

Bioburner will have a better answer for you and I think I just read something about this on a 45 in another thread possibly. I have a PC45 and they are great older stoves and run well IF they are set up correctly. Good Luck and let us know.

P.S. FYI, I just had a friend with a brand new Advance and he was running stove mode / Constant burn thinking he didn't need his room sensing probe. He couldn't get his Distribution blower nor flame to ramp up when he adjusted for more heat. Plugged in the Room Probe and problem was solved immediately. So I think you do need a room probe plugged in.

 

[bags]

Findyourway & JP99,
Put your stove model in your signature too so people know what you are running. There are numerous 45 peeps here and we all hang pretty tight. Many have tons of knowledge about these stoves. I am newer but have a vast knowledge of them Thanks to these guys. They are great older stoves basically replaced by the P43 and the P61. There are also many seasoned former 45 owners glad to chime in and help.

The 45's are the same chassis and size as the 61's. Same trims fit etc; Same doors, fire box, on and on.... The 45's difference is they have two burn pot options and can burn 100% multi- fuel whereas neither the 43 or 61's can. They can do a 50 / 50 corn pellet mix well and probably even more corn once they are running and have the flame established.

IMHO the 45's are soon to become a classic stove that can hang with and do more than some of the new technology of a Harman.

 

[jp99]

Nice pellet porn pics there. I am pretty sure you need your room sensing probe plugged into your stove for it to operate correctly regardless of the mode you are running. They are pretty cheap and easily found on the net at various pellet stove parts suppliers and / or a dealer. Buy one and plug it in.

Thanks bags. I just checked my PC45 manual from Harman and the room temperature probe is listed as optional, and I do recall in the early days not using it. So the stove works without it - at least my model from 2007 does. I do have one installed now but haven't run in room temp mode in years. I always use stove temperature mode.

I do have a signature and I do see it here when I'm using a regular computer. From my smartphone I don't see any signatures and that might be how the mobile version of this site works.

 

[jp99]

I have a PC45 and they are great older stoves and run well IF they are set up correctly.

I agree. It took me a couple of seasons to get this dialed in near perfectly. I ran different amounts of corn/pellets, and logged all the settings I had on the stove along with the inside and outside temperatures. I collected/logged some 15 pages of data that showed me how to set up the stove for different levels of performance and what I could expect, and how much fuel was used up over time (I even installed self-adhesive tape measures in the hopper so I could accurately measure fuel usage). Some 15 columns of data and 45-50 lines per page, and copious notes/comments.

A lot of great information from those logs, such as what happens if you use the larger hole burn pot with the small combustion fan plate when burning corn; or small hole burn pot with large combustion fan plate. I only use a few settings today, but I know how the stove works on almost any combination of settings and hardware. Nothing beats experience and good data for tuning this stove.

With the so far mild winter in Ohio, I'm burning on low power and not producing any clinkers on the stir rod. It's running nicely.

 

[bags]

The 45's dist. blowers will cease to run if the stove temp is not hot enough which is likely the case then. At least when I run mine low the blower will shut down unless it is up to a certain temp.

I see your sig now. Sorry if I missed it but I didn't see it before or overlooked it. I went up and east into Ohio to buy my 45. Where are you in OH? I am in NKY about 32-34 miles SW of Cincinnati. Bought my stove out in the corn fields of OH somewhere close to Winchester, OH. Mom's whole side of the family lives somewhere in OH from Columbus south and east. One uncle has a farm in Pike County another in Adams Co. Most are in or around Cincy though.

The guy I bought from always burned 100% corn. he didn't clean stoves well either. If he ever did.

Mt 45 is a 2007 but I think it was made late 2006. I know the 1st owner didn't get it until '07. Probably exactly the same stoves. My serial # is WHI 006121 and was sold new at Southern Ohio Stove in Georgetown, OH 45121

 

[OverlookEGR]

Love the IR pics. I have a PC 45 as well. It has been quite a mild winter so far here in Western NY.

 

[jp99]

I'm up in northeast OH, around the greater Cleveland area. I got my stove at Hillside Heating near Norwalk, and my corn is from the nearby Hauck Seed farm. So I travel a bit for fuel and parts.

I'm not at home right now so I don't have my serial number handy, but it sounds like we have the same stoves. Hartman overbuilt stoves around 2006-7 and mine was one of those overstock units on sale ($2400). I love the multifuel option and wouldn't want anything else.

 

[bowyer2002]

I have a PC45 and I am having similar problems it was installed in 2007 or 2008.

the distribution blower doesn't want to come on

I recently cleaned my stove and it was working fine.
I have turned off the stove, unplugged it for a while doing the usual 'computer circuit board' reset/reboot and restarted.
I have removed and cleaned the ESP
There is a room temp sensor plugged in.
My stove auger works, there is ignition, stove was PLENTY hot (tonight) but the distribution blower will NOT turn on, EXCEPT for in test mode.
However, when test mode it switched off - the blower goes off.
SO -
there is fuel
there is ignition
the blower motor works

I'm wondering if the circuit board is bad or if the blower control (thermostat?) switch is bad.

ANY suggestions would be appreciated - thanks!

 

[jp99]

What mode are you using? If you've bumped the switch to Manual and you're in Stove temperature, the distribution blower won't come on unless the stove is extremely hot or you're above a 5 setting (it's a fireplace kind of mode).

 

[bowyer2002]

@jp99
I now have it on Stove temp, earlier I had it on Room Temp (when it wasn't working)
Since my earlier post this evening and unplugging it again with a restart and being set on Stove Temp mode it seems to be operating okay.
i.e. the distribution blower is working!
That being said, I am afraid to change any of the settings since it is working!

 

[bags]

I'm up in northeast OH, around the greater Cleveland area. I got my stove at Hillside Heating near Norwalk, and my corn is from the nearby Hauck Seed farm. So I travel a bit for fuel and parts.

I'm not at home right now so I don't have my serial number handy, but it sounds like we have the same stoves. Hartman overbuilt stoves around 2006-7 and mine was one of those overstock units on sale ($2400). I love the multifuel option and wouldn't want anything else.

The 45's are great stoves. Not a sports car but a great running diesel truck. They are tanks and will throw some awesome heat.

 

[bags]

@jp99
I now have it on Stove temp, earlier I had it on Room Temp (when it wasn't working)
Since my earlier post this evening and unplugging it again with a restart and being set on Stove Temp mode it seems to be operating okay.
i.e. the distribution blower is working!
That being said, I am afraid to change any of the settings since it is working!

Have you ever replaced your ESP probe? As in is it the original or an old one. If you are positive everything is clean then it sounds like this could be the issue. It's not your distribution blower because it functions in test mode. As JP99 stated you could be in a mode where the blower gets by passed. If not it is likely your ESP. There are others more well versed here with the 45's so maybe they will throw out an idea I'm not. They do have different vacuum requirements than my P68 which I mainly run.

For example the 68 runs without the hopper lid closed. This may not be the case in older 68's. My PC 45 is a 2006 and the 68 is a 2014 so 8 years is a vast difference in tech.

 

[bags]

I have a PC45 and I am having similar problems it was installed in 2007 or 2008.

the distribution blower doesn't want to come on

I recently cleaned my stove and it was working fine.
I have turned off the stove, unplugged it for a while doing the usual 'computer circuit board' reset/reboot and restarted.
I have removed and cleaned the ESP
There is a room temp sensor plugged in.
My stove auger works, there is ignition, stove was PLENTY hot (tonight) but the distribution blower will NOT turn on, EXCEPT for in test mode.
However, when test mode it switched off - the blower goes off.
SO -
there is fuel
there is ignition
the blower motor works

I'm wondering if the circuit board is bad or if the blower control (thermostat?) switch is bad.

ANY suggestions would be appreciated - thanks!

Bio Rickwai??

 

[OverlookEGR]

I have noticed over the last year that the speed control for the distribution fan seems to be going bad. It is a potentiometer that can go bad in spots and work in other spots. I am going to attempt a circuit board repair one of these days and install a new one. They are an inexpensive part I just need to find a supplier that sells them currently.


Sent from my iPhone using Tapatalk

 

[bags]

I have noticed over the last year that the speed control for the distribution fan seems to be going bad. It is a potentiometer that can go bad in spots and work in other spots. I am going to attempt a circuit board repair one of these days and install a new one. They are an inexpensive part I just need to find a supplier that sells them currently.


Sent from my iPhone using Tapatalk

Yes, could also be a finicky pot switch

 

[Bioburner]

Yes the distribution fan should work in manual but the temperature setting needs to higher than the rooms temperature. I run my stove this way as I have a crosslink boiler installed and don't need the blower on most of the time and have the temp set and 63 or so. If the ESP is bad it can keep the distribution fan from running thinking the stove is not up to temp and being a corn burner it is pretty important to have the stoves temp up to keep from crudding up the interior and venting. Now the room probe may well be dependent on what board as they have made 3 board versions and I had a stove that if it was not installed would not even start but throw a code. Put me in panic mode as my first stove I sold had a party driving 2 hours to get and it would not come on then I looked in the hopper and there sat the probe, installed it and all was well. The party never wanted to see it run, just loaded up and left
Great pictures jp99. I need to get a roll of IR film and shoot some pictures

 

[bowyer2002]

My celebration was premature.
1.5 hrs after I posted it was working it had stopped.
I put it back into ROOM TEMP mode, turned it on & went to bed.
Woke up this morning and the stove was cold and there were no blinking status lights to indicate why.
I tried to restart it just now and the feed auger isn't feeding fast enough to keep the burn pot fed.
I'm stumped!

BTW - I am burning hardwood pellets with the feed set at 3.5, room temp half way between L&H and the temp dial at 85 and the igniter set on auto.

 

[Bioburner]

When was the last time the stove had a new probe? A funky pot switch will give no end of grief too Seems the ESP can have a life of 3-5 years for the most part but some last far longer. I have to get another on order as I installed a new one last year as well as a set of pots. I am running a first generation board and that board does not start a shut down mode if the UPS runs during a power outage. Replaced the pots on it and like its burn algorithm as they are slow to ramp up and down over the newer faster reactions. I have a new last gen in waiting as I had a issue with room probe shorting and the board was looking like a Christmas tree with all the lights blinking and stove acting strange.

WARNING to all, get the stove on a good surge suppressor or preferably a UPS. Hundred or so bucks now or be cold and paying $200-275 latter. These winter storms are killers

 

[bowyer2002]

My whole stove is OEM - that being said, it looks like I need a new ESP and see if that solves my problem(s).
Can anyone provide the part number for the probe or link to get it on line?
Thanks!

 

[Lake Girl]

The ESP is listed as thermistor probe on this parts list https://www.manualslib.com/manual/65586/Harman-Stove-Company-Pc-45.html?page=27
3-20-00744 part number. There are two different probes ... one with black wires and one with red. This looks to be the black wired one which, naturally, is the more expensive of the two.


http://pellethead.com/product-tag/harman-pc45-esp-probe/
http://www.stove-parts-unlimited.com/Harman-Thermister-Probe-ESP-Probe-p/3-20-11744.htm