Harman PF100 furnace

feed rate wont make a real difference in heat, unless you set it too low. Do that, and you might be replacing your auger weldment......

 

Check which auger motor/rpm you have on, hopefully the previous owner switch it with a different one. It's as been known to happen. This has nothing to do with why the furnace is not shutting down but more on feeding to fast.

 

It has a 10rpm on it the new one I have is 6rpm

 

I hate to say to much cuz I'll jink my self lol.
But here I go I put the new 6 RPM auger motor on.
Not sure this all makes scenes but this furnace has never worked this good.
Keeps a smaller fire when not working, blower dosnt turn on and off because chamber is hot.
And to beat all it actually shut its self down when I turned the t-stat down

Is this posable ??????

 

There you go
My hunch was off base but came through
Let's see how it goes from here

 

I'm not concerned with the blower coming on but when it was raising the house temp 3-5* with out the furnace actually working I don't think that's rite? , may as well be using a uncontrollably wood burner .
When it's cold and t-stat is left alone I don't think it would ever go out. From my testing it appears it takes a min of 30 mins with out T-stat calling for it to shut down.
So far, from what ever freak reason it running like "l" think it should now

 

the blower actually checks the temp in the plenum and operates from that, basically independently of the stove temp, depending on the temp settings of the plenum switch....and that part is something that we do occasionally sell.

 

lets way oversimplify this.....
all the blowers work.
both feeders work.
the circulation blower seems to work.
What controls it all? The CB and probe. They tell the stove when to feed, shut down, etc. Im wondering if the probe is reading incorrectly (never getting down to "shutoff" resistance), or the new board is simply faulty. A check with the DDM will tell you what the probe reads.
I have seen new circuitboards be bad (not so rare). Ive seen new probes bad (rare).
OP mentioned the vac switch bypassed. This allows the feeder to run when it shouldn't be able to. Its simply closed or open. Check continuity.....at normal atmospheric pressure, its open. If a vacuum exists >-0.15 " water, it closes, energizing the feeder and igniter circuit.
As for why the fire is staying in even at off, takes me back to CB or probe.

 

IDK it's decently odd ...
I'm not sure what a DDM is or how or what I need to check it ... like I said I'm not beyond buying maintenance equipment... I'd rather be sure than buy more parts.
With the 6RPM motor everything appears to be working as it should even the vac switch is hooked up and working.
I know there's a concern with the slower motor " back burning" into the pot I don't want to create more issues.
I ordered all new gaskets and have intentions of striping furnace soon inspecting and replacing anything that looks bad.
Just for chits&gigles I put the 10rpm motor back on today it went rite back to its old way ?

 

Strange indeed

 

Ok I have my furnace completely tore down , did a super clean job on it ( almost looks new inside now)
I've been able to find all the gaskets/parts I need but one item.
I noticed the little glass window in the door has a hair line crack in, I'd like to replace it but my dealer says the glass and gasket are NLA. So I'm hoping one of the older dealers may have one on shelf .. if anyone has one or knows of one let me know ... if I can find one guess I'll weld a plate over the hole.

 

If this is a window that's exposed to the firebox, it's not glass but ceramic "glass". If you can get it out, a local glass shop should be able to cut you a replacement.

 

Yup. Ceramic "glass". I know of no dealer who stocks it. Ive never seen one broken before. My local glass guy keeps glass and cuts to size.....maybe one near you?

 

Great idea I'm sure I can get one cut .. guess I'd have to male a gasket also

 

I have the same problem that EC does. My PF100 won't shut down, regardless of what I set the thermostat to. It kicks on and runs a small maintenance fire until it is out of pellets. When I change the ESP (black wires) the problem goes away for a while or so but then the stove starts doing it again. I've gone through quite a few ESP's over the years. I clean the probe regularly and I am careful not to damage it. My question is about changing to the newer revision of the CB and the red wire EDP. I've been told that red ESP is more durable and will last longer. I was wondering if any of you guys have any thoughts/opinions on this. I feel like I am wasting a lot of pellets.

 

Welcome to FHC oscarmaggie
The furnaces aren't quite running yet so the furnace folks are still enjoying summer
I'm sure someone will pop in soon enough
You can PM Lousyweather as he's the Harman guru

 

Welcome oscarmaggie!

Calling Lousyweather