Harman humming noise

[NEW_NH_USER]

Hello!
Recently bought a used 2005 XXV. Often there is a loud humming/squealing noise coming from the combustion fan area. I assumed it needed a new fan (maybe it still does) but recently discovered the following...when I open the hopper the noise goes away.

What does this mean? Is my stove struggling for more fresh air and the noise is the sound of that? Or do I have a leak?

I have the original Harman wall pass through. It looks like it may be adjustable but I can't find a manual to know what for.

Thanks for any help!

 

[Mt Bob]

Well assuming you have the Harman wall thimble with outside air,check inside the tubing for restriction,check thimble,check air flap in air inlet,back of stove,but might just be someone left one of the thumb screws loose on the combustion blower.

 

[Lake Girl]

Opening the hopper shuts down the auger ... potentially auger motor going? Auger flight needs cleaning? Fines from feeder body cleaned
lately?

 

[Mt Bob]

Opening the hopper shuts down the auger ... potentially auger motor going? Auger flight needs cleaning? Fines from feeder body cleaned
lately?

probably not,should not have a hopper lid switch,too old.

 

[Lake Girl]

Forgot that not all Harman's have a hopper switch. Feed body may still need attention but may be best to pinpoint sound. Bearings on distribution blower going ?

 

[corkman]

Hello!
Recently bought a used 2005 XXV. Often there is a loud humming/squealing noise coming from the combustion fan area. I assumed it needed a new fan (maybe it still does) but recently discovered the following...when I open the hopper the noise goes away.

What does this mean? Is my stove struggling for more fresh air and the noise is the sound of that? Or do I have a leak?

I have the original Harman wall pass through. It looks like it may be adjustable but I can't find a manual to know what for.

Thanks for any help!

Disconnect outside air for now and see if that makes s difference. If noise goes away then you may have a blockage in the oak. With the oak disconnected get behind the stove and make sure the air flapper is moving freely

 

[bogieb]

Opening the hopper shuts down the auger ?

That was my first thought. Doesn't need to be because of a hopper switch either.

Could be that opening the hopper lets in enough air that it causes the vacuum switch to activate (or is it deactivate?) this would cause the auger to stop feeding just as opening the viewing door does.

 

[NEW_NH_USER]

Thank you all for the replies! I got home today and re examined the stove. I noticed fresh air intake port flex hose was not attached properly. I fitted it on and sealed with foil tape and I'm up to an hour of run time with no humming. Hopefully that was it!

Not thrilled with the shoddy install. Tried to save some time by hiring it out due to so many projects going on but I guess if you want something done right...well, you know...

 

[Lake Girl]

Thank you all for the replies! I got home today and re examined the stove. I noticed fresh air intake port flex hose was not attached properly. I fitted it on and sealed with foil tape and I'm up to an hour of run time with no humming. Hopefully that was it!

Not thrilled with the shoddy install. Tried to save some time by hiring it out due to so many projects going on but I guess if you want something done right...well, you know...

Glad to hear it was only the OAK line was off and not something more serious. Better to find it now before real heating season. Sorry to hear about the poor install.

 

[Peterfield]

Thank you all for the replies! I got home today and re examined the stove. I noticed fresh air intake port flex hose was not attached properly. I fitted it on and sealed with foil tape and I'm up to an hour of run time with no humming. Hopefully that was it!

Not thrilled with the shoddy install. Tried to save some time by hiring it out due to so many projects going on but I guess if you want something done right...well, you know...

See, you should have gone without an OAK. Ducking now.

 

[Lake Girl]

See, you should have gone without an OAK. Ducking now.

What? I guess you would want to hear it squeal or hum all the time

 

[bogieb]

In all fairness, the flex hose is not the easiest thing to get tightened all the way. I installed both my own, and have had to tighten them down at least once since the natural vibrations can make things move. Don't use tape since I block up the pipes during summer and plus, I just don't want to

 

[NEW_NH_USER]

There was no actual attempt to affix the hose...it was just propped up as if pretending that it was attached.

Looks like i may have spoke too soon. The noise is back. It comes and goes. Seems to happen when stove is on a slow burn and not so much when roaring. It happens both when the auger is spinning and when it is still as well.

I replaced the combustion fan to no avail. I was hoping it could be the source of the noise but it was really old so I wanted a new one in there either way. New one works like a champ but didn't resolve the squeal.

 

[Mt Bob]

Need to locate noise.A mechanics or doctors stethoscope with the end removed works well.So does a section of tubing held in one ear.Pull off oak hose and see if sound changes when covering with hand.Clean fines box,make sure cover gasket is ok.Empty hopper and vacuum the slide plate.Could also be a loose screw some where,also could be something like bad hopper gasket,or silicone sealer inside hopper has fallen out.Good luck.

 

[NEW_NH_USER]

Going to see spend more time on it this weekend and will try to isolate the noise. It's been driving us nuts!