Simson DuraVent Close Clearance Connector (CC-C) - Very insecure connection

[John_M]

The topic defines the problem. This connector connects any stove pipe to their ceiling support box. One must insert the connector and twist-lock it into position. The tabs which "lock" the connector into position are shallow and poorly constructed. After making certain the connector is properly inserted and twist-locked, I can quite easily pull part of it out of the ceiling support box. This connection is so weak that I am afraid six feet of stove pipe will also pull it easily out of the support box.

I called Simpson Technical Support to see if a fix is available and their recording said my message is important to them. I should leave a message and someone will call me back within two hours. I left a very angry response with my telephone number. My anger was spontaneous and unnecessary and will probably be non-productive.

I do not believe this problem is unique to my situation because I telephoned a stove shop and their installer indicated this has been a long standing problem with this Simpson connection. Their certified installer was not aware of any available fix which would comply with the UL rating of the pipe. There is no way to screw the pieces together without losing the UL rating. And the constant pulling and shoving the pipe to telescope it for cleaning will most certainly pull this connector out of the ceiling support box. Then I would have a "mell of a hess" on my hands.

In fairness, I must say their ceiling support box, chimney and double wall stove pipe are excellent products; well made and finely finished. This connector is the weak link in an otherwise excellent system.

Can anybody familiar with this system offer any suggestions for a fix? Merely replacing the (CC-C) with a newer piece probably will not work unless the newer units have deeper tabs. I am afraid to start screwing around with opening the tabs myself because I would probably make it even worse.

This had to happen toward the end of my installation. What a disappointment!

John_M

 

[Todd]

Can you smear stove or furnace cement around the pipe and then install into support box?

 

[John_M]

Todd, I hadn't thought of that fix but with the tabs holding just a teensy bit, the extra adhesive quality of the furnace cement might provide the strength needed to securely hold the pipe. I am going to wait a day or so before I become too frustrated with the poor design of this connection. Who knows, Simpson Technical Support might still return my phone call. I also just called a local dealer where I purchased the pipe and their certified installer was/is very aware of this problem. He is currently out doing an install so we will talk in the morning. I'll see what fix he has used in the past.

Simpson is such a reputable company. I am quite disappointed they have allowed this problem to go uncorrected for so long.

Thanks for the tip.

John_M

 

[BrotherBart]

Hard to imagine somebody saying that putting three screws in that connection would void the listing when the Close Clearance Connector installation instructions say:

"When connecting to another manufacturer’s chimney system, always screw snap connector
into place.

When connecting new and old style double wall pipe, use a minimum of (3)
screws at each connection (#8 x 3/8" screw) equally spaced."

Looks like if screwing it to somebody else pipe doesn't void the listing, screwing it to their own pipe shouldn't either.

 

[John_M]

Todd and BrotherBart, I return to the topic much humbled and with my tail between my legs. A very knowledgeable and courteous Technical person from Simpson just returned my phone call and explained that the looseness is okay as long as the connector was inserted and twist-locked into place. The connector does not support the suspended stove pipe; the stove does. The connector cannot fall out of the ceiling support box unless the connector is unscrewed and the tabs aligned with the insertion slots in the support box. He said that connection system will make sense as soon as I purchase the DVL double wall pipe and see how it fits.

BrotherBart, I agree with your conclusion about the screws not voiding the UL Listing. That's the intuitive answer. I just re-read the same instructions you quoted and the three screws attachment system is the required and best way to hold the pipe pieces together.

An interesting side note: I telephoned another fairly local Simpson dealer and he said the Close Clearance Connector does not twist lock into place; it just snaps into place. Oh Well!!

The result of my posting, phone calls and wringing of hands is that everything is fine. My installation will be well done and I will enjoy the safety and warmth of my new stove for years.

I would suggest Simpson include instructions which describe various options specific to this connector because most persons might not yet have any other installation instructions available.

Thanks for the help. I'll sleep better tonight.

Best wishes,

John_M

 

[BrotherBart]

The dealer is right, it is a snap versus twist lock connection. I started to mention the stove holding the pipe up but didn't know if it was top or rear vented. With rear venting you don't want a load on the pipe at the stove end.

I'd still put screws in the sucker if it was mine. I have the same Simpson snap lock connection into the thimble on my F3 CB and it has three in there for sure.

 

[jtp10181]

I have had to remove one of these connectors that was in service for 2 years... trust me, they do not fall out. All the creosote makes a good seal. They do snap in, and also twist.

I am going from memory and I don't install every day but I am pretty sure the end going in the class A pipe snaps in to install, and to remove you twist it to a certain position where the tab channel is open and it comes out. If you happened to install it right into this channel it would fall out, so you just twist it to lock it in. The other end which goes in the DVL pipe I think just snaps in and stays, I think to remove it you have to use a screw driver and force the tabs out.

When you install the close clearance adaptor pay attention to the flow arrow on the part # sticker. It can be installed upside down but it will not work correctly. I had a customer install his entire DVL pipe run upside down and then come into the store insisting the adaptor was defective and did not fit correctly. He had pulled all the stickers off everything before he attempted to install it.... Not only was he jamming the adaptor in upside down, but then he was also trying to put it into the wrong end of the DVL pipe.

 

[John_M]

There was no sticker on the CC-C when purchased but it was a new unit; no scratches, etc.. It is installed with the larger end into the ceiling support box. The smaller end is facing down and will fit inside the DVL pipe when installed. Any creosote will be funneled inside the pipe down to the stove.

Somewhere in some instructions it mentions that the tabs on the CC-C should be aligned with the four slots on the chimney support box. It is then inserted into the chimney support box and twisted to lock. If it were not twisted it would fall out just as jtp suggested.

Brotherbart, I am going to place three of the #8 x 3/8" screws into each of the pipe connections, for sure. Using the 3/8" screws is also recommended by Simpson. I am assuming from all their literature that I have read, that, as a general statement, as long as the screws penetrate only the outer shield and do not compromise the inner pipe the UL rating should not be voided.

I'll try to find 3/8" truss head sheet metal screws at Lowes or a fastener supply house.

The exhaust system on my stove is a perpendicular line from the top of the chimney to the top of the stove. There are no elbows or bends in the system. The stove will be a PE Spectrum (ordered yesterday) with a top exhaust. With this configuration the weight of the stove pipe is supported by the top of the stove and not the chimney support box, as Bb suggests.

The installation at the ceiling support box to the top of the chimney is done extremely well. It is structurally strong with a minimum of 3 1/4" of clearance to combustibles. The chimney penetrates the roof at the ridge so I built a chase for the chimney to facilitate flashing of the installation. A local roofing guy did all the roof work and did an expert job. He built a temporary aluminum top flashing on the chase for use until my custom one is finised later this week. We have had some torrential rains recently and not one drop of water penetrated his installation. I have already recommended him to others.

Thanks for all the help, guys. Your tips have given me confidence this installation will be completed as well as the various components allow.

Already have about two cords of wood, a mixture of splits and rounds which is already seasoned, and another cord to split.

Planning my first break-in fires to cure paint on stove pipe, etc., in early August.

The assistance offered by various members of the Hearth site over the last several months has been invaluable. You have always kept me going in the right direction.

Best Wishes,

John_M