New boiler circulator pump question


Old 08-02-16, 06:53 PM
Thread Starter
Join Date: Jan 2015
Location: USA
Posts: 18
New boiler circulator pump question

Hello all,
I have been away for a bit since I finally got my boiler working properly last fall-winter! I had high pressures, and added a very large- etx 90 expansion tank which took care of the problem (after running through a ton of possible scenarios and replacing many different parts). I guess I have a ton of water in my system and when it heated and expanded called for a large relief space....

Regardless, Mass Save program has all kinds of great incentives for new boilers and energy efficient heating components so I am gonna bite the bullet and go for it. I am doing a hydro-air system with heated coil. I will have 2 or 3 zones of forced hot water baseboard and CI radiator, and 1 zone for the main portion of the house with the 'forced warm air'. The issue is, my plumber who is a good friend of mine and I trust very much wants to put the circulator pumps on the return.... After all I have read on here (and elsewhere) about having them on the supply in the 21st century, I have concerns about efficiency and air removal etc..

The 3 boilers I have to pick from WM ultra 3 (nervous about the alum heat exchanger), HTP elite FT, and TT prestige solo. He wants to pipe it, primary secondary. I trust him, however the circ placement concerns me.

Can anyone shed any light on the issue, or give me a boiler that MUST be piped with the circ on the supply per manufactures specs lol.

Thank you all soon much!
Sponsored Links
Old 08-02-16, 08:53 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,471
Upvotes Received: 16
I can't help you in deciding on a boiler beyond my personal dislike for an aluminum heat exchanger. I do like the primary/secondary method of piping multiple zones. As for placing the pumps on the returns, ABSOLUTELY NOT! Pumps on the supply side is not just 21[SUP]st[/SUP] century but dates to the middle of the last century. There are many reasons to pump from the supply and no legitimate reasons to pump the returns.
Old 08-02-16, 09:44 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 51,425
Upvotes Received: 214
There are many reasons to pump from the supply and no legitimate reasons to pump the returns.
I'm an electrical/electronic person so I don't do any new boiler plumbing but I'd think the pumps would run cooler if they were on the return side.
Old 08-03-16, 06:52 AM
Join Date: Apr 2014
Location: us
Posts: 569
Upvotes Received: 2
Would like to see the pro's and con's of pump location.

With today's integrated pump/motor/electronics packages, running with return water 20 to 30 degrees cooler seems like a plus.

MTBF usually goes up with temperature rise. That is one legitimate reason for putting pump on return side.

Last edited by doughess; 08-03-16 at 09:45 AM.

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