Finding Replacement Part for Harman PP38+ Pellet Stove

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Agrippina65

New Member
Dec 4, 2024
16
United States
Hi friends,
Those who have responded to my previous threads might know that I've been trying to get a Harman PP38+ pellet stove fixed. A friend of mine who is an electrician used a meter to figure out that there is a switch connected to the motor that no longer works (pictured below). He jumpered the terminals and the auger started working normally again, so apparently I have cleaned out the dust sufficiently. The part number on the side of this switch is
MPL-9370-V-0.16-N/O-HRZ. I searched for this part on several sites and found similar switches, but this exact part number doesn't seem to exist any more. My friend told me I'd need to find a part with the same pressure and amperage. Does anyone know what the modern part number would be or, failing that, what pressure and amperage a replacement would need to be? For some reason, there is no mention of it in the manual. Thank you in advance.


[Hearth.com] Finding Replacement Part for Harman PP38+ Pellet Stove
 
That vacuum switch appears to be 0.16 InH2O. Just get in touch with your choice of parts supplier. Get one as close as you can.
If you get 0.2 then it is "safer" but could create a problem. If you get 0.1, then more chance of problems that are not good. The stove designer picked it, so I would go higher 0.2 with a cheap aftermarket and try that.
 
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Thank you for the advice. I'll see what I can find. Do they not make this exact part any more?
I have no idea. I was going to add that the first start would be to get the original PN from your manual, and try and buy that, but I re-read you post, and I guess that it was not found? Very strange as it is a major part. Any 120V Normally Open Vacuum switch that they sell for a pellet stove will work. Get as close to 0.16 as you can.
 
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The PP38+ is in their stoves that this works in list, hope this helps


 
No, unfortunately the only mention of the switch at all in the manual is a diagram of it with no information. I tried searching using the information you gave me (2.0 InH20) and unfortunately, I found nothing at all. There were some pressure switches but most of them didn't even look similar to mine. They were big metal things, and the ones that were similar didn't even have the plug prongs in the same place or shape. I came up completely empty.
 
The PP38+ is in their stoves that this works in list, hope this helps


unfortunately, the plug in that one is not the same shape or configuration. The plug on mine has the two prongs close together in an L shape. Thank you for looking though.
 
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unfortunately, the plug in that one is not the same shape or configuration. The plug on mine has the two prongs close together in an L shape. Thank you for looking though.
Don't worry about the prongs (Terminals) as they are standard size. The switch you have a picture of may have been designed for a plug, but you can just use new female insulated terminals on the wire to hook up a new switch. If it is a Vac sw for a pellet stove then it should be good with a little work

Here is -0.15 which is closer than others that will probably be 0.05 or 0.10

Try to find it in the USA as I see it was a Canadian link.
 
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Don't worry about the prongs (Terminals) as they are standard size. The switch you have a picture of may have been designed for a plug, but you can just use new female insulated terminals on the wire to hook up a new switch. If it is a Vac sw for a pellet stove then it should be good with a little work

Here is -0.15 which is closer than others that will probably be 0.05 or 0.10

Try to find it in the USA as I see it was a Canadian link.
THank you! I believe I've found an American version of the switch. I appreciate the help.
 
Check Amazon
Also the replacement switch for your unit is here
Thank you very much! There is a part number on the old switch that matches the numbers listed on this page. I appreciate the help.
 
When you electrician friend tested this did they apply a vacuum to it when tested? Also did you check you seals and such and make sure the stove does not have a vacuum leak somewhere since this is what this is designed for, may have a bad door seal or something
 
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Any vac switch with 0.10 inches of water will work
 
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