Supply vs. Retun piping


  #1  
Old 08-20-08, 10:52 AM
D
Member
Thread Starter
Join Date: Aug 2008
Location: Illinois
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
Supply vs. Retun piping

I am currently replacing a 50 yr. old hot water baseboard heating system in my home with a new Weil McLain Ultra 80. I can mount the new unit on the wall directly above the supply/return lines to the system, however, the lines are on the opposite sides as the new boiler. Does it matter, on a closed loop system, which line is supply and which is return?
 
  #2  
Old 08-20-08, 11:18 AM
Who's Avatar
Who
Who is offline
Member
Join Date: Jan 2006
Location: San Jose
Posts: 2,066
Upvotes: 0
Received 2 Upvotes on 1 Post
Keep the heating circuit flowing the way it did and pipe the boiler pri/sec like in the installation.
 
  #3  
Old 08-20-08, 02:58 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
In some cases you could probably reverse the flow, but there are a few reasons not to.

First, if you have ANY MONOFLO aka VENTURI TEE fittings in the distribution piping, NO, you can not reverse the flow.

Depending on how the piping runs, the original installers may have installed manual air bleeds at specific points in the system. If he knew what he was doing, those would be installed at the points that air is most likely to collect in the system, usually anywhere the piping turns to go DOWN there will be an air bleed.

If you reverse the flow, now those bleeders will be located where the flow is coming UP, and possibly, no air will collect there. So, you could be left unable to bleed any air pockets...

You've also got items such as 'air scoops' and 'flow check' valves that won't operate properly with flow reversed.

The answer is MAYBE.

But, understand what WHO is saying also... follow all manufacturers recommendations regarding installation.
 
  #4  
Old 08-20-08, 03:27 PM
rbeck's Avatar
Member
Join Date: Jul 2007
Location: United States
Posts: 2,407
Upvotes: 0
Received 66 Upvotes on 55 Posts
Normally the heat goes to the warmer rooms first than cooler rooms such as bedrooms. The installing contractors did that to take advantage of the 20º delta-T of the system. Reverse it and rooms which you have adjusted to being warmer or cooler will reverse.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: