Hampton GC60 smokin' up the house

[Leaky Waders]

My dad installed about three years ago a Hampton GC60 pellet stove. It is mounted in the central living room of a ranch house. The exhaust is vented horizontally through the back of the stove and out the side of the house. The stove was purchased brand new and installed professionally.

Short story: the system is leaking smoke into the house, and has been basically since the word go. The installers came back out and put a pipe extension outside. That did not help. They came back out, and quite literally gooped up the exhaust pipe with a ton of caulk. Still, she leaks smoke. Then they came back out and recommended a fresh air exchange. That was installed, and verily, the smoke continues to leak. Then it was suggested that my dad was burning less than ideal pellets (Lignetics), so he switched to premium hardwood pellets (Hamer's). And indeed, she smoketh still. My dad keeps the stove super clean, but if you run your hand down his walls, they will come away with a skim of black soot. It ain't good.

Now, a new fella has come out, and said that the stove pipe needs to be mounted up (to be clear, it can be mounted horizontally out of the house, but then needs an elbow and long vertical pipe). He claims that the fresh air exchange cannot be mounted right next to the end of the exhaust pipe. He has quoted my dad a price, but the frustration level is sufficiently high that my dad doesn't think the new length of vertical pipe will solve the problem. At this point, he wants the stove out of his house.

Before he does that, I wanted to offer this conundrum up to a crowd sourced solution of folks who know pellet stoves. I am a woodstove insert guy, so this is not my territory. Thanks in advance.

 

[Mt Bob]

Wow,that is bad.That stove should function fine with a horizontal flue.I really suspect an internal gasket problem,from the day it was built.Go to HVAC shop,get some smoke bombs for checking ductwork,put in stove(stove is off),you might be able to find something.However if it is a crack,might not leak until hot.If you cannot "see" a problem,recommend a complete teardown,or,if it has been documented from the start,request a new stove.Good luck.

 

[scotthershall]

Hmmm. I'm not familiar with that specific stove but, as suggested, the horizontal flue should be just fine. When I first installed my Englander the Duravent flue pipe I used leaked from every conceivable place even though I used sealant inside when putting it together. I ended up using more sealant on the exterior of the flue at every joint. Then I found the vent cap at the bottom of the clean out tee was leaking through the cap itself, so I had to seal that up really well. I had to use silicone tape (Nashua makes it and it's sold in Lowe's/Home Depot) to seal up the vent cap at the joint and other pieces I couldn't seal with actual sealant. (Some smoke got around it initially but it stopped pretty quickly.)

Here's a link to a post I made about my stove install... you can see all the sealing I needed to do to stop the vent from leaking! https://www.hearth.com/talk/threads/venting-questions.141991/#post-1975214 That pretty much solved all the leaks. I replaced the silicone tape on the 90 joint with black hi-temp sealant and repainted the whole thing.

To test for smoke, turn the stove off and let it cool. Then restart it and turn off all the lights so it's nearly pitch black (maybe do it at night) and get out a good flash light. Go around the flue and see if you can see smoke with the flash light. Then try to seal it up the best you can with sealant or silicone tape.

Where the flue goes through the wall, did the installers use a piece long enough to make it through all the way (not two pieces of pipe)? Might be worth checking if you can - that would be a tough area to seal after the fact. If you found this to be the case, I'd replace it with a longer, single flue pipe.

Other than this you might try taking some panels off the stove to take a look at the combustion blower. Although I'm not familiar with your father's specific stove, most pellet stoves work by sucking air through the stove (rather than pushing it through), so you're really only looking for leaks after this blower. Perhaps a housing on the blower is cracked or a gasket is bad?

The new guy's advice isn't terrible but I don't think it will solve this problem (but I'm just some hack-job DIYer so you know, take that with a grain of salt...). A vertical piece would allow for some natural draw should your father loose power (until the pipe cools I guess), but it's not necessary. And plenty of vent kits have the outside air intake (which I think is what you're taking about) within inches of the exhaust.

Lastly, does your dad have a carbon monoxide detector? That's what would worry me about leaky vent pipes!

 

[Tails1]

Hmmm. I'm not familiar with that specific stove but, as suggested, the horizontal flue should be just fine. When I first installed my Englander the Duravent flue pipe I used leaked from every conceivable place even though I used sealant inside when putting it together. I ended up using more sealant on the exterior of the flue at every joint. Then I found the vent cap at the bottom of the clean out tee was leaking through the cap itself, so I had to seal that up really well. I had to use silicone tape (Nashua makes it and it's sold in Lowe's/Home Depot) to seal up the vent cap at the joint and other pieces I couldn't seal with actual sealant. (Some smoke got around it initially but it stopped pretty quickly.)

Here's a link to a post I made about my stove install... you can see all the sealing I needed to do to stop the vent from leaking! https://www.hearth.com/talk/threads/venting-questions.141991/#post-1975214 That pretty much solved all the leaks. I replaced the silicone tape on the 90 joint with black hi-temp sealant and repainted the whole thing.

To test for smoke, turn the stove off and let it cool. Then restart it and turn off all the lights so it's nearly pitch black (maybe do it at night) and get out a good flash light. Go around the flue and see if you can see smoke with the flash light. Then try to seal it up the best you can with sealant or silicone tape.

Where the flue goes through the wall, did the installers use a piece long enough to make it through all the way (not two pieces of pipe)? Might be worth checking if you can - that would be a tough area to seal after the fact. If you found this to be the case, I'd replace it with a longer, single flue pipe.

Other than this you might try taking some panels off the stove to take a look at the combustion blower. Although I'm not familiar with your father's specific stove, most pellet stoves work by sucking air through the stove (rather than pushing it through), so you're really only looking for leaks after this blower. Perhaps a housing on the blower is cracked or a gasket is bad?

The new guy's advice isn't terrible but I don't think it will solve this problem (but I'm just some hack-job DIYer so you know, take that with a grain of salt...). A vertical piece would allow for some natural draw should your father loose power (until the pipe cools I guess), but it's not necessary. And plenty of vent kits have the outside air intake (which I think is what you're taking about) within inches of the exhaust.

Lastly, does your dad have a carbon monoxide detector? That's what would worry me about leaky vent pipes!

^^^^This x2. Where the flue goes through the wall make sure it's one length all the way through the wall and that there isn't a joint inside the wall thimble. Also the flashlight trick is what I used when I had a leak in my pipe after my install and silicone tape around every joint is what I did to correct them. I had to use quite a bit of it. Pissed me off as that pipe isn't cheap and for what I payed for it it shouldn't be leaking.

There should NEVER be any combustion products entering the house from the stove ever (no smoke, smell nothing), if there is then something is wrong. Check the pipe connection where it connects to the stove as well.

 

[vinny11950]

Follow the previous advice from the other posters, especially the flashlight trick on startup, at night with lights off, using an LED flashlight. Be ready to crawl around the pipe shining the light at different angles. I have had great success finding leaks shining the light from the bottom up.

If you have any pictures of the install, exhaust pipes inside and outside the house, please post them.

 

[scotthershall]

To test for smoke, turn the stove off and let it cool. Then restart it and turn off all the lights so it's nearly pitch black (maybe do it at night) and get out a good flash light. Go around the flue and see if you can see smoke with the flash light. Then try to seal it up the best you can with sealant or silicone tape.

To clarify, you're shutting the stove down and restarting because you want it to use the smoke it produces when smoldering before flames appear to check for leaks. (This is how my stoves starts up - I assume other stoves are similar.) If you have a smoke bomb, that would probably work too, but I never seen one of those let alone used one.

Good luck! Let us know what you find!!