Questions on an HB36A, popping noise from flue?

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castironfanatic

New Member
Oct 10, 2022
2
Omaha, Nebraska
Hi all,

I recently purchased a new home in the Omaha area and in the process acquired a fireplace. We've used it a handful of times and really enjoy it. I have a couple questions/concerns with it. I had a chimney sweep come out to do an inspection and cleaning before we started it up. They said it looks great good to use and asked me if I had any questions, but I didn't have any at the time. I'm thinking about calling them back up but figured I would drop my questions here first to see what all of you thought. The fireplace we have is, I believe a Heatilator HB36A, manufacture date of '88.

I noticed when I turned on my central heat that I hear a popping noise initially when the heat turns on for a good 5 minutes or so. The popping noise starts out fast and slows down until it stops entirely. At first I thought it was an issue with the ducting in my home, but after further inspection I now believe it is actually the flue of my fireplace. I think I am losing air out of my fireplace and the flue is expanding as hot air escapes. I made sure the damper was fully closed and doors shut. The bi fold doors of course don't have a tight seal at all and the damper doesn't seem air tight by any means. From what I read it isn't realistic to replace the doors with something that seals better, replacements will all be equally as leaky. Is this true? Am I better off to replace the damper with something that has a better seal, is this the way to go? Is there another way to resolve this that I should be looking into?

My other question is regarding the outside combustion air kit. I read the manual and see an outside air kit referenced (CAK4) but don't see any explanation of how to control it. There is a little lever in the lower right side of my fireplace. I believe this is to control the air flow. I can't find in the manual how to tell if it is open or closed! Push in or out? I think it might be stuck open no matter what I do.

I'm thinking about replacing it with a more efficient epa certified unit in the future, but want to get some life out of this one as I save up. Your help is appreciated!

Thank you,

Justin
 
Hey Justin,

Yeah sorry man, it looks like you've found everything you can on it. I took a peek as well, and I found install instructions for the CAK4, but that's about it. Have you tried getting in touch with Heatilator at all? It looks like they're still up and running, so I wonder if a quick message off to them would yield any helpful results?
 
Thanks for the message RomanW. I tried to reach out to Heatilator but they direct the request to the closest Heatilator dealer in the area. They just recommended using an inflatable fireplace plug, which I could do during the longer periods that I am not using it. They said there would not be a tighter sealing replacement damper. However the chimney sweep did say there was a type that can be installed toward the top of the flue and then a pull chain is installed inside the fireplace. I might have them handle that the next time they are out. I also got some of those magnetic vent covers to try, they stay up alright. I think if I get them trimmed just right I can get it to work better and maybe tape a handle onto it or something so I can reach in and pull it off easier.
I've gotten absolutely no answers on the combustion air kit. I ran it the last couple of times with the lever pulled all the way out. I am going to try it with the lever pushed all the way in next time and see if it acts any differently. Other than that all I can think to do is pull the vent off the outside of the chimney and see what I can see as far as the mechanism that controls the air kit.
 
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Reactions: RomanW
That sucks man, I'm sorry to hear that. Sounds like you've got some headway on some other stuff though! Will be interesting to see how it turns out!