Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing


Thread Tools Search this Thread Display Modes
Old 11-17-2010, 03:29 PM   #1
Join Date: May 2009
Posts: 4
Share |

Proper gas line installation for wall furnace


I recently bought a house with a guest house in the back. There is a gas line outside the back of the guest house that feeds a direct-vent wall furnace. The connection goes from black iron gas pipe to a flexible "corrugated" gas line, but THEN goes through the wall from the outside to the inside, then connects to the furnace.

Recently, the local Gas company was out and noted that the connection from the outside to the inside using a flexible gas line through the wall was not allowed according to code - not at all unreasonable by the way.

I went to the furnace manufacturers' website and their installation instructions indicated that rigid pipe should be used all the way to the gas valve, with a "ground joint union" used to connect to the gas line where threading into the existing pipe was not possible.

My question is: Could I just continue the rigid pipe from the outside to the inside of the house, and THEN use a flexible gas line from the end of the rigid gas pipe to the gas valve? That's how the stove and water-heater are plumbed - it seems to me that the issue is that the flexible gas line should not be on the exterior (not as durable) nor should it be in the wall (hidden, potential for punctures, etc.) But once the rigid line is terminated properly inside the house, a short flex line to the gas valve in the furnace should be okay.

Does anyone disagree?



rsaritzky is offline   Reply With Quote
Old 11-17-2010, 05:04 PM   #2
DIY staff
Join Date: Sep 2009
Location: Kane county,Illinois
Posts: 21,110

Proper gas line installation for wall furnace

Flexible lines to permanent fixtures are against code in my area---Why don't you want to hard pipe it?

oh'mike is online now   Reply With Quote
Old 11-20-2010, 12:39 AM   #3
Join Date: May 2009
Posts: 4

Proper gas line installation for wall furnace

Originally Posted by oh'mike View Post
Flexible lines to permanent fixtures are against code in my area---Why don't you want to hard pipe it?
The main issue is the working space for putting a union in in order to connect the 2 pieces of pipe. The furnace is a short one (about 30 inches high) mounted mid-height on the wall. The current flex line goes in through the wall right behind the lower part of the furnace, then makes makes one 90-degree turn directly into the gas valve. Unless I want to punch another hole in the wall, there's very little room to get in a union. I could possibly connect a nipple to the gas valve, then with one elbow, go back through the wall with a second piece of pipe, then put the union on the outside of the house where it would connect to the existing gas line. But getting the lengths of pipe exactly right so it would line up with the riser outside the house will be tricky, because I'd have get a correct length through the wall then get the pipe cut and threaded at the hardware store (I don't have the equipment to cut/thread pipe myself). By using a flex connector for the last "leg", then I have a little more flexibility in the alignment of the hard pipe. But I did not know that flex wasn't allowed in fixed appliances. I looked at the furnace in my main house and the gas line is hard pipe into the furnace closet which terminates at a shutoff valve, then there is a flex connector from the hard pipe into the furnace. So this seems to also be contrary to the code in your area. And THIS furnace was inspected by the same gas company guy. I'm in California, so maybe flex connectors are allowed - perhaps because we're in earthquake country? The inspector seemed concerned just about the flex connector going through the wall, not that there was a flex connector involved - otherwise I would have expected he would have told us that hard-pipe was required all the way to the furnace.

But thanks for your question and opinion - it's appreciated!

rsaritzky is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Furnace and possibly AC recommendations MzzGriz HVAC 16 08-09-2010 09:00 PM
Proper installation of vapor barrier in basement faromic80 Remodeling 3 12-11-2008 05:48 PM
Proper installation of register boot hartkem HVAC 5 11-15-2008 10:44 PM
Central Air Installation vs. Oil Furnace shnfldr HVAC 6 06-20-2008 06:49 AM
Furnace Exhaust To Outdoors celticFC HVAC 1 09-01-2007 01:27 PM

Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.