Switching from oil to gas: Do i need to change the chimney liner?

Reply

  #1  
Old 11-11-13, 01:27 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
Switching from oil to gas: Do i need to change the chimney liner?

So yeah i posted a thread about changing from an oil to gas boiler here:

http://www.doityourself.com/forum/bo...ml#post2185272

I just realized that the contractor didn't inspect the chimney and i can't remember if it was suggested i changed the lining or not a few years ago.

It seems changing the liner would cost about $2000 based on what i've googled.

If i go with a high efficiency gas boiler instead of a conventional one, they could just drill a hole in my basement wall and vent outside instead without having to vent up the chimney, correct?

Or if the current chimney liner is ok, there's no problem with switching from a low efficiency oil boiler to a low efficiency gas boiler, correct?
 
Sponsored Links
  #2  
Old 11-11-13, 02:07 PM
Member
Join Date: Oct 2008
Location: USA
Posts: 2,846
NFPA 211 is the code that applies to chimneys, vents, etc. It doesn't automatically require changing the liner, but it does require a "Level II" inspection when changing the boiler to one that is of a dissimilar type, input rating, or efficiency. The inspection is specified to include some 66 points. Depending upon the results of the inspection, you could be obliged to make changes to the chimney, liner, connections, etc. It is up to local jurisdictions to implement the code through ordinances or regulations, so your situation may vary. Even if the code isn't applied in your area, it would be a good idea to conform to it. And, the boiler manufacturer may have additional requirements.

If you switch to a high-efficiency condensing boiler, you need to comply with the installation requirements of the boiler manufacturer. Check the proposed manufacturer's website for venting requirements.

What are you planning to use for hot-water heating? Here in natural-gas country, most people choose to use a separate, non-condensing, stand-alone gas water heater. If that's the direction you wish to go, the water heater will have to be vented - possibly into the vent used by the boiler itself if it's non-condensing.
 
  #3  
Old 11-11-13, 02:23 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
hi gilmorrie: We have an electric hot water heater that we'd like to re-use.
 
  #4  
Old 11-11-13, 03:42 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Likes Received: 1
I think that if you've got a liner for oil that it would be stainless steel and be fine for gas.

BUT...

It may be TOO LARGE for the new appliance, and I always recommend an INSULATED liner.

So, yeah, you might have to change it.
 
  #5  
Old 11-11-13, 04:20 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
NJ Trooper,

Nuts! I heard that can cost like $2,000 to change!

I wonder if i should go for a high efficiency boiler like this instead of a low efficiency/conventional boiler and just do a direct vent to outside and save the hassle:

383-800-001 - Weil Mclain 383-800-001 - ECO 110 - 88,000 BTU Output Natural Gas Wall Mount Gas Boiler

I'm surprised such a unit is so cheap, it's only about $1000 more than the low efficiency boiler my contractor suggested.
 
  #6  
Old 11-11-13, 04:38 PM
Member
Join Date: Oct 2008
Location: USA
Posts: 2,846
It may be TOO LARGE for the new appliance
Yep. One of the 66 inspection points specified by NFPA 211 for a new, dissimilar boiler, is: "That the chimney liner and vent connector diameter is proper for the appliance(s) connected." I don't know how many, if anybody, works methodically through all those 66 inspection points.

But, here is a question. The code specifically allows a gas hot-water heater to be tied into the boiler flue. Many millions of water heaters are installed that way, including mine, with no problem. Why are there not condensation problems when the water heater is running by itself, alone, without the boiler or gas furnace?
 
  #7  
Old 11-11-13, 04:42 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Likes Received: 1
I heard that can cost like $2,000 to change!
I could see a liner install going that high... I just installed one here at home in a 15' chimney and materials alone were around $500. I had the spouse cut me a check for a grand for labor... ha ha ha yeah right, like THAT will ever happen!


I'm surprised such a unit is so cheap
I took a quick look at it... I dunno... how can they charge so much less than Triangle Tube, which is a quality boiler.
 
  #8  
Old 11-11-13, 06:06 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
NJ Troooper:

"I took a quick look at it... I dunno... how can they charge so much less than Triangle Tube, which is a quality boiler."

Yeah i was wondering the same. Is Weil Mclain highly regarded?
 
  #9  
Old 11-11-13, 06:13 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Likes Received: 1
Is Weil Mclain highly regarded?
Not sure how to answer that. It's the Ford vs Chevy debate. Some love 'em, some hate 'em. I'm in neutral...
 
  #10  
Old 11-11-13, 06:54 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 17,722
Likes Received: 2
. Is Weil Mclain highly regarded?
They have thier place..... ( but not in my home)........
 
  #11  
Old 11-11-13, 07:52 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
Lawrosa: What manufacturers do you suggest?
 
  #12  
Old 11-11-13, 08:04 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 17,722
Likes Received: 2
Atmospheric or HE? .....................
 
  #13  
Old 11-11-13, 08:07 PM
Member
Thread Starter
Join Date: Sep 2009
Location: USA
Posts: 35
lawrosa: either? ...........
 
Reply

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


Thread Tools
Search this Thread
Display Modes