Harman P35i Chimney Liner Rumble

[Mr. Heat Miser]

I just finished installing my Harman P35i pellet insert and fired it up this morning. I installed it myself, took my time, and followed all the instructions exactly. The stove works great and my entire downstairs warmed up within an few hours of lighting it. The only thing is, I am experienceing a low frequency rumbling noise every so often. It almost sounds like when a car drives by your house with the giant subwoofer in the trunk. It can get quite loud at times. It seems to be being caused by the exhaust blower. I think it's the chimney liner vibrating, almost like when you blow across the top of a beer bottle, but I am not sure. I used a 4" 316Ti Stainless Steel Chimney Liner and ran it to the top of the chimney, then capped it with a terracotta flue cap with a roof and a round opening and band collar connection. I also used the lintel kit which secures the inserts frame into the fireplace opening by tightening some threaded rods against the lintel bar at the top of the fireplace opening.

Is rumbling a known or common problem with chimney liners? Any other ideas on what this noise could be? If it is the liner, any ideas on how I might correct it?

Thanks for any suggestions.

 

[MCPO]

Has anyone taken a draft reading ?

 

[HarmonP35i]

did you install a outside air kit?

 

[imacman]

.....4" 316Ti Stainless Steel Chimney Liner and ran it to the top of the chimney, then capped it with a terracotta flue cap with a roof and a round opening and band collar connection......

Can you post pics of chimney cap set-up?

 

[summit]

they used to have the same problem on the first runs of the accentra insert. check your flame guide (the cast iron trangle widget above your burn pot)... does it have a curve to it? If it is flat, get one with a curve, it'll solve the problem. I know the sound you mean: it sounds like there is someone blowing over the top of a giant beer bottle thru your liner.

 

[Mr. Heat Miser]

Has anyone taken a draft reading ?

Not yet... when I got to that part in the install, I asked the dealer if they typically measure the high and low draft, and they said no, that only about 1 out of every 100 needs an adjustment because the draft is tested and set at the factory. I wanted to test it, but didn't have a meter myself. I have asked the dealer about the rumble, and they are going to come out and take a look at it. They will bring their draft meter and diagnostic meter. I'm curious what they will find, because as I say, I meticulously followed the install instructions, checked and double checked everything before I fired it up. I'll post their findings after they come out on Wednesday.

 

[Mr. Heat Miser]

did you install a outside air kit?

No, I asked the dealer about it several times, and even had them come and take a look at my house and they said the outside air was not necessary. My house is 2500 sq ft and tight, but not super tight. I asked several dealers about the outside air and they all recommended against it.

 

[Mr. Heat Miser]

.....4" 316Ti Stainless Steel Chimney Liner and ran it to the top of the chimney, then capped it with a terracotta flue cap with a roof and a round opening and band collar connection......

Can you post pics of chimney cap set-up?

Here's a pic of the chimney cap I used

 

[LIpelletpig]

This is a common problem with Accentra Inserts. Not sure if it transitioned to your model as well but my stove is going on season 3 and it makes the noise on start-up and on a HIGH burn. Once the stove is warmed up it goes away. I originally didn't have an OAK and last year I installed an OAK and noticed the stove didn't burn well and it made no difference. I removed the OAK and the stove burns much better. No reason why but the OAK was installed to manufacturer specs. If you search the forum under Accentra Insert Roar or rumbling you'll get some info on the issues as well. Your install sounds fine and it doesn't sound to me as your issue. For curiosity sake, while the stove is making the sound open the pellet hopper lid. See if the sounds goes away.

 

[mdlyen]

I just had a P35i installed and encountered the same rumbling sound. The dealer seemed to think it had something to do with the gasket on the hopper lid. Something about it allowing air into the hopper and causing the rumbling. He has had a couple customers complain about the same thing. It does seem to only happen when the stove is cold so once it warms up, I forget all about it.

I will post back if my dealer comes up with anything. He already had the Harman rep out to visit one of the other customers (if you believe that)...

 

[MCPO]

Has anyone taken a draft reading ?

Not yet... when I got to that part in the install, I asked the dealer if they typically measure the high and low draft, and they said no, that only about 1 out of every 100 needs an adjustment because the draft is tested and set at the factory. I wanted to test it, but didn't have a meter myself. I have asked the dealer about the rumble, and they are going to come out and take a look at it. They will bring their draft meter and diagnostic meter. I'm curious what they will find, because as I say, I meticulously followed the install instructions, checked and double checked everything before I fired it up. I'll post their findings after they come out on Wednesday.

The dealers answer was somewhat evasive . The draft reading should be done after the install since it usually has more to do with the chimney (vent) than the stove. However you ae doing the right thing in having it checked.

 

[MCPO]

did you install a outside air kit?

No, I asked the dealer about it several times, and even had them come and take a look at my house and they said the outside air was not necessary. My house is 2500 sq ft and tight, but not super tight. I asked several dealers about the outside air and they all recommended against it.

That`s BS, typical dealer`s sales pitch. Most of them prefer to say outside air isn`t necessary . I think soley because it makes an installation easier, quicker, and cheaper. BUT only slightly on those three counts, at least on most typical installs.
That said it probably isn`t the cause of the chimney noise either.

 

[Lousyweather]

Has anyone taken a draft reading ?

Not yet... when I got to that part in the install, I asked the dealer if they typically measure the high and low draft, and they said no, that only about 1 out of every 100 needs an adjustment because the draft is tested and set at the factory. I wanted to test it, but didn't have a meter myself. I have asked the dealer about the rumble, and they are going to come out and take a look at it. They will bring their draft meter and diagnostic meter. I'm curious what they will find, because as I say, I meticulously followed the install instructions, checked and double checked everything before I fired it up. I'll post their findings after they come out on Wednesday.

The dealers answer was somewhat evasive . The draft reading should be done after the install since it usually has more to do with the chimney (vent) than the stove. However you ae doing the right thing in having it checked.

yea, a bit tough to check the draft if you dont have the meter.....i second the above....any rumbling we ever heard was the flame guide....there's 3 different types of Harman guides, the oldest and most common being a flat one, but the correct one has a concave top...this solved any issues we had (2-3) with "rumbling units"....the ones I heard sound more like a train going by slowly

 

[tjnamtiw]

First, with an install into an existing chimney, an OAK is just about impossible unless you want to bore a hole through the back of the chimney. Possibly, you could use the ash cleanout door, if it has one, but not very easy to do and the insert will probably sit right on top of it. The run up the chimney for the OAK would be too long.
Next, when you had a roaring fire in the old fireplace, you never noticed rumbling?????? I'm sure you did, but you got used to it and it died down when the fire slowed down. Same thing with your insert but the smaller diameter pipe exaggerates it. People who have never burned a real fireplace have never heard the 'roar' before and get all bent out of shape. I'm not talking the roar of a chimney fire now! %-P That one you'll NEVER FORGET!

 

[Lousyweather]

the outside ait kit is an accessory with an insert........but you dont have to punch a hole into the firebox......it pulls the air out of the space between the liner and the old masonry chimney for its outside air.

 

[tjnamtiw]

the outside ait kit is an accessory with an insert........but you dont have to punch a hole into the firebox......it pulls the air out of the space between the liner and the old masonry chimney for its outside air.

Not if you do it right and seal off the top of the chimney with a plate through which the liner goes! It's a dead air space if you also block off the smoke shelf, otherwise you will end up pulling the air from the room.

 

[Nicholas440]

I have a Quadrafire Castile insert and its going on 3 years now, and it rumbles but mine rumbles due to the round design of the firepot and the holes it has in it. Actually, I really like that rumbling sound, I can turn away from the flame and hear that rumble and I can picture in my head exactly what the fire looks like because Ive watched it while that rumble sound was going on. Its not continuous it dies down, and comes back depending on the size of the fire, and the air coming into the firepot.

I'll bet your Harmon has the same type of issue, with its firepot design. Watch your fire for a while and note at what point the rumbling occurs if its similar to mine it will be when the fire reaches a medium size or larger. I normally dont hear the rumble when the fire is real small . As I say I really like that sound it reminds me of when my fireplace was roaring years ago when I burned logs. Some people compare the sound to blowing across the top of a bottle too.

 

[Lousyweather]

the outside ait kit is an accessory with an insert........but you dont have to punch a hole into the firebox......it pulls the air out of the space between the liner and the old masonry chimney for its outside air.

Not if you do it right and seal off the top of the chimney with a plate through which the liner goes! It's a dead air space if you also block off the smoke shelf, otherwise you will end up pulling the air from the room.

when using the Harman outside air kit, "doing it right" ISNT sealing off the plate.

 

[tjnamtiw]

when using the Harman outside air kit, "doing it right" ISNT sealing off the plate.

Well, how does Harman recommend that you DO terminate the flex liner at the top of a 20' chimney AND use the outside air kit? If you don't seal off the top of the chimney, how do you keep rain from getting in? I'd like to know, because I have two inserts that don't have OAK's.

And what is Harman's recommended maximum run for the OAK piping?

 

[Lousyweather]

when using the Harman outside air kit, "doing it right" ISNT sealing off the plate.

Well, how does Harman recommend that you DO terminate the flex liner at the top of a 20' chimney AND use the outside air kit? If you don't seal off the top of the chimney, how do you keep rain from getting in? I'd like to know, because I have two inserts that don't have OAK's.

And what is Harman's recommended maximum run for the OAK piping?

perhaps you should look at page 22 of your Accentra Insert manual........if your is old, or you cant find the manual, you can go to Harman's website and download a manual which MAY be more recent than your own. Most, if not all, of the info is in the manual, if one takes the time to look.

 

[tjnamtiw]

perhaps you should look at page 22 of your Accentra Insert manual........if your is old, or you cant find the manual, you can go to Harman's website and download a manual which MAY be more recent than your own. Most, if not all, of the info is in the manual, if one takes the time to look.

No, if you look at my signature, you'll see I have two Quads. I was asking what Harman knows about OAK's up chimneys that, evidently, Quad doesn't know so I could add an OAK to mine.

 

[c_mantle]

I hope you resolve your issue! I'm making the decision this week to go with either a P35i or Accentra insert.
Can you give me any guidance? Other than cost...why'd you pick the P35i.
The feed range of the Accentra is very attractive but I think the P35i is more efficient.

Any feedback would be helpful.

 

[Lousyweather]

perhaps you should look at page 22 of your Accentra Insert manual........if your is old, or you cant find the manual, you can go to Harman's website and download a manual which MAY be more recent than your own. Most, if not all, of the info is in the manual, if one takes the time to look.

No, if you look at my signature, you'll see I have two Quads. I was asking what Harman knows about OAK's up chimneys that, evidently, Quad doesn't know so I could add an OAK to mine.

well, then, like I said, the manual is available online, and should answer your question

 

[camdids]

The Harman Manual gives a diagram clearly showing the outside air Pipe ending inside the Chimney ,Halfway up. If sealed at the top and at the Damper , the only air is through the Brick Chimney. Isnt It??

#1 Installing into an existing fireplace
method provides excellent venting with
100% outside air which is the most efficient operation
of this unit. This method also provides natural
draft in the event of a power failure.
A 4 inch stainless steel flex pipe is needed for
the flue pipe, and 3" aluminum or Stainless Steel Flex
Pipe is used for the intake.
In Canada and some places in the US it is required
that the vent pipe extend all the way to the top
of the chimney.

 

[tjnamtiw]

well, then, like I said, the manual is available online, and should answer your question

Remind me to take you off my Christmas list, Lousysomething.............................