Harman P series- P38+, P43, PC45, P61, P68

I have owned about a dozen pellets stoves over the last 7 or 8 years, 4 of which have been Harman's (Advance, P61A, P61 , and PC45). I could approach the P series as 5 separate reviews, but I think it is more useful to look at the as a group. The P series stoves really have more in common than they do have differences.

Harman pellet stoves function in some fundamentally different ways than just about any other pellet stove on the market. I am of the opinion that Harman makes the best pellet stove on the market, and the P series represents the best of Harman pellet stoves. This review will hopefully explain how I arrived at that conclusion.


Lets start with what all Harman's have in common-

Pellet Pro system

The first thing is what they call the Pellet pro system. This and one other thing are what makes a Harman a Harman.

This system is about as close as you can get to a bottom feed system, without out being a bottom feed system. The reason you do not see bottom feed systems is because the were prone to hopper fires. The pellet pro system makes a hopper fire almost impossible (or at least very unlikely) because it creates a separation between the pellets in the hopper and the pellets in the auger. To my knowledge no other pellet stove manufacturer does anything like this.

Early Harman Pellet Pro model
This system is common to all Harman's, in fact the very first series of pellet stove Harmon made was the Pellet Pro series. An other benefit to this system is that the variations in different size pellets does not effect feed performance.

Harman's have "ESP"

The second thing that really sets Harman stoves apart is the use of what they call and ESP probe. Now some of you might hear ESP probe and think it is a device used on ghost hunters, but that is not the case. The ESP (Exhaust Sensing Probe) basically measures the temperature of the exhaust and regulates the feed rate based on the exhaust. By knowing the exhaust temperature you can extrapolate the heat output of the stove.

When you turn most stoves to a particular setting you are basically controlling the feed rate, and that rate is a fixed amount of auger rotation over a fixed amount of time. So the same setting on a most stoves can equal rather different different stove heat outputs based variations in pellets, and as you know from this site there can be some real significant variations in pellets.

By contrast Harman stove temperature settings 1-7 reflect a paticular exhaust output temperature and will automatically adjust the feed rate to maintain a consistent output at the given setting. This system works extremely well, and harman has been perfecting it for over a decade now, so it is a very mature system.

Stove Temp versus Room Temp

The other common feature to all Harman pellet stoves is the room temperature sensor. It is basically the temperature probe for the onboard thermostat. So you can essentially set a room temperature and the stove will keep it there by raising and lowering the fire, and if it does not call for heat over an extended period the stove will shut off, and then relight when heat is called for again (with the exception of the P38+).

Here is where I offer a couple criticisms about the Harman system. It is difficult (not impossible) to hook in a programable thermostat to the stove. The second is that running a Harman in room temperature mode is not nearly as efficient as stove temperature mode.  I always run my stoves in stove temperature mode, and they work great.



Things specific to the P series


P series with nickel options
I would say the best way to describe the P series is that form follows function. These are some of the most functional stoves made, however they are not the most decorative or fancy, in fact one might even call the austere.

Cleaning

These are just one of the most simple stoves to completely clean. Basically open the door, scrape the burn pot out, scrape the accordion heat exchange (common to P series), brush the ash down into the ash bin, open the bottom door and pull out the ash bin (which is huge btw), pull off the exhaust fan cover and clean and vac out that area (be care around the ESP), and done.

One you are experienced this whole process should take 20 minutes if you take your time. About one a year you should also remove the door to the feed system and vac it out. This requires removing one of the lower baffles.

These are all very simple tasks compared to other stoves.

One interesting thing Harmon does is that the housing for the combustion fan is part of the stove, and it is offset in such a way that you can see straight out of the exhaust.

I realize this is sorta inside baseball stuff, but if you are a DYI type it makes ownership of the stove a much more pleasant proposition.


Differences in the P series


Pellet Hopper Capacity 

The P series has generally above average hopper capacity. Essentially the P series has 3 frame sizes- small (P38 and P43- 50 LBS), medium (P61 and PC45- 72 LBS), and large (P68- 76 LBS). All these can be increased with a sinfully ugly hopper extension, but if you are burning these in a basement the hopper extension might be just the thing you need. They typically add about 50 LBS of capacity, and is a feature unique to all the P series stoves.


Power

This is an area where Harman pellet stoves shine in general, and the P series in particular (even the P38 is pretty strong. I have heard it said that Harman pellet stoves put out heat like a wood stove, and it is true. As I mentioned before I have owned a number of other pellet stoves, and none of them put the real world heat out like Harman.

The P series in particular give you a considerable amount of radiant heat in the room they are in. Most other pellet stoves do not put out much in the way of radiant heat at all.


Build Quality

Before
Durring
These are USA made stoves. They are made in Halifax PA, just a little north of the state capital of Harrisburg. Generally speaking they are just a heavier made stove, the steel is thicker than a lot of other stoves. The fit and finish is also very good, doors line up and latch as they should. I am actually in the process of refurbishing a 17 year old P61 that was clearly not cared for well, and with a little effort it will come up as good as new, and that is a testament to initial quality. Like anything parts will fail, but the frame of these stoves are rock solid.







Differences within the P series.

The first thing to note is the number after the P in the model indicates the maximum BTU input to the stove in thousands. For example a P61 has a maximum BTU input of 61,000 BTUs.

P38+ versus P43

These are pretty much the same stoves, but the P43 has auto light. In terms of the difference in 5,000 BTUs between the models, I suspect there is a very minor real world difference between the stoves.

P61 versus PC45

These stove are the same frame size, but there is a huge difference in the burn pots. The p61 is s pellet stove, the PC45 is a pretty much anything palletized stove. The PC45 comes with an additional burn pot, and 2 different agitators that connect to the end of the auger to stirs fuels like corn that want to clinker very quickly. There is also a series of dip switches that need to be set differently for different fuel types. I currently burn a PC45 set up for pellets, and it seems to have a similar heat output as my P61 did.

P61 versus P68

The P68 is a minor increase from the P61. The dimensions of the stove are nearly identical, with the P68 being 2" taller, and holding 4 more pounds of pellets. The burn pot is a bit larger as well. If you are trying to heat a large space this is your stove. This stove will put out more than many wood stoves, and was the highest output free standing pellet stove on the market.



Conclusion

As you can tell I am a fan of these stoves. My recommendation of the P series stoves in the P61. It is powerful enough for most applications and just does almost everything well. I have found the loner I owned a Harman the more I liked.


Eventually I would like to get a XXV as it blends the great functionality of the P series with the great looks of a classic cast iron stove. I look forward to writing that review.










10 comments:

  1. I just bought a pc45 to burn wood pellets. can you install a wall thermostat on them

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  2. How have you owned a dozen stoves in eight years? It seems like they are either breaking very fast or you are moving a lot, in which case you can't have used then for very long, so your review doesn't cover any sort of longevity usage.

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  3. The Harman uses more pellets (a lot more) than other stoves no matter what setting is used. That is why it puts out heat like a wood stove. There are so many btu's in a pound of pellets. Have you ever used an Auburn St. Croix. It is way more effecient. Fuel to heat output. Not as hot as the Harman when both on the max setting but not far off, but half the fuel usage. Amazing stove, and more reliable than the Harman. Very few parts to go bad 10 years and not one part has needed replaced. 2 years with the Harman and Ive replaced 3 stirrer rods, 1 esp probe, 1 room sensor and 1 igniter, meanwhile the Auburn is on its 12th year running at the inlaws and they love it. Don't get me wrong Harman is a great stove but I know of at least one better one. And its not that bad to clean ... a couple times a season.

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  4. I should report a stat. Same house. Auburn averaged about 2lb/hr of pellets to keep the house warm. The Harman 4lb/hr to keep the house at the same temp. The Auburn is designed in that all heat has to go up past the exchanger and behind the back wall to be exhausted so more heat is captured by the exchanger and distributed tot he room . less out the exhaust. The Harman sucks some heat out underneath the burn pot so it doesnt all get to the heat exchanger on the top. Simple yet smart design. Also another point is the auburn exchanger is easier to clean , it has a scraper rod that cleans the heat exchanged tubes very well, I find it kind of difficult to clean the Harmans accordion style exchanger especially with the supplied pointed scraper deal. I wire brush works a little better. I use the Harman simply for the ease of use , the auto ignition is very convenient.

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  5. I have the opportunity to buy a PC 45 for $800. Ad states it's in 'excellent condition' however the picture shows it sitting outside of a shop (for however long it's been there I have no idea. I am handy and it would be late spring before I could install it anyways, providing time to go through and refurbish it as needed. Does this seem like a decent price? I was thinking of tossing a $500 cash price his way but I don't want to seem to be disrespectful if his price is fair?
    Thoughts? Thank you for the excellent write up!

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  6. I recently purchased a 9 year old functioning Harman P61 that I hope will offset my heatpump electric bill this winter, it should. After the current heating season I was considering completely refurbishing it as you did, my question is: do the P61a (auto igniter) parts fit in a P61? Essentially I'm looking at rebuilding it as a P61a. This is my first time working with any pellet stove.

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  7. We just bought a P-43 upon recommendation of the dealer for size. I will have other questions, but the first one is what mode to run it on. Constant burn seems to give the better heat BUT we would be going thru pellets like candy. The Room temp mode holds back the candy consumption BUT we don't feel as warm.. Ok now at constant burn we had it on #3 and distribution blower midway. On Room Temp mode we had it at 72 and blower at midway as well. feed rate for both set at 4.
    we have a 2000 sq. ft 5 yr old house. stove is located on lower level, (as that was coldest level and our heat pump was not able to really keep that warm and it is where our living room and daughters bedroom is) we have an open floor plan so stairway from two levels is all open. This house has all been insulated and good windows. On upper level there is a propane gas-log vent free BUT it is very costly for the propane , and was only good for heating right there, not for beyond .. We live in E.Tennessee. so we have moderate winters. Last night it was 20 deg and today it is 36 . We have stove on Room Temp mode of 70 and our upstairs is 66 that the heat pump is having to keep running to keep it up.. The downstairs level where the stove is is a bit more comfortable than upstairs but we are not running around in shorts or short sleeves... I guess my question is how to run the stove for warmth, heat and efficiency. And second question is did we get an adequate size stove.?
    thank you in advance.

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    1. We bought a P68 recently to heat our 120 yr old 2000 sq ft farmhouse that we are not finished with making it more airtight. We (I) get cold easily and wanted something that would heat our home easily. We are in the midwest and it's been around zero lately and have no issues at all keeping us warm. Granted it will eat pellets, but it is very efficient at keeping our house comfy! It took us a few tries to figure it out. We tried constant burn but I didn't care for how many pellets we were going through. Also, being that we leave it on while we are gone, I wanted it to keep at a constant temperature. We found that leaving it on 76 with feed rate set to 3 and room temp just below midway and leaving room sensor behind the stove as recommended works best for us. Our front room is hot of course and have doorway fans on the way to help transfer heat to have the other rooms and hopefully be able to knock it down a notch. Considering we currently have no fans going, our front room is at 76 and the back of our house is at 70 (all rooms are 16x15 and this goes through 3 rooms). This stove works far better than the crappy US Stove King Pellet stove that we previously had that came close to burning our house down! There is a way to calculate the btu/sq ft ratio but with a 5 yr old home I am sure it is more airtight than our home and should work just fine. You may need to crank up the temp another degree or two and tinker with blower. Hope this helps!

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    2. We bought a P68 recently to heat our 120 yr old 2000 sq ft farmhouse that we are not finished with making it more airtight. We (I) get cold easily and wanted something that would heat our home easily. We are in the midwest and it's been around zero lately and have no issues at all keeping us warm. Granted it will eat pellets, but it is very efficient at keeping our house comfy! It took us a few tries to figure it out. We tried constant burn but I didn't care for how many pellets we were going through. Also, being that we leave it on while we are gone, I wanted it to keep at a constant temperature. We found that leaving it on 76 with feed rate set to 3 and room temp just below midway and leaving room sensor behind the stove as recommended works best for us. Our front room is hot of course and have doorway fans on the way to help transfer heat to have the other rooms and hopefully be able to knock it down a notch. Considering we currently have no fans going, our front room is at 76 and the back of our house is at 70 (all rooms are 16x15 and this goes through 3 rooms). This stove works far better than the crappy US Stove King Pellet stove that we previously had that came close to burning our house down! There is a way to calculate the btu/sq ft ratio but with a 5 yr old home I am sure it is more airtight than our home and should work just fine. You may need to crank up the temp another degree or two and tinker with blower. Hope this helps!

      Delete