Zone Valve Usage Question

Reply

  #1  
Old 10-28-08, 02:35 PM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Zone Valve Usage Question

I have a small house that I'm remodeling the basement in that currently has hot water heat. I'm installing hot water baseboard heat in the basement with 3/4" plumbing. The house is old and the existing heating plumbing consists of a continuous 1 1/2 inch pipe around the perimeter of the basement that has venturis at each tap off for the upstairs radiators. I need to divide the upstairs and basement into two zones.

My initial thought was to put a 1 1/2 inch zone valve into the existing plumbing for the upstairs and a run-of-the-mill 3/4 zone valve for the new basement plumbing. Problem is the biggest zone valve I can find is 1 1/4 inch and I didn't want to use a single one in the upstairs plumbing for fear of reducing the flow enough that it affects the flow through the upstairs radiators. I did the math and found that I could split the 1 1/2 pipe into two parallel sections and use two 1 1/4 zone valves wired to operate together to get the flow I need, combining back into the single 1 1/2 inch pipe.

I've been told I should use circulators instead of zone valves for this purpose since I can get circulators with flanges big enough to accommodate the 1 1/2 inch plumbing, but since there would be some leakage I should be adding backflow check valves and on and on. In my mind this just complicates things and adds more things to break.

I'm open to suggestions/opinions, but if I can get the 1 1/4 zone valves for a decent price I can't see why this wouldn't work providing I have the power needed to run the valves.

Anyone care to comment?
 
Sponsored Links
  #2  
Old 10-28-08, 09:33 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
I think I would go with circs... and flow checks ... you can use a itty bitty circ on the 3/4" zone, and that can be boughten with an internal flow check (or IFC) inside the pump.

You would have to add a flow check to the big zone ...

This way too, if it happens that the new basement zone calls for heat, your big ole pump isn't way overpumping that zone...

You can use a Taco SR-502 or 503 (to have a spare relay channel) to switch the circs ... real easy to wire ...
 
  #3  
Old 10-29-08, 05:44 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Thanks for the input. So, looking at the controller already on the boiler (Honeywell) the existing circ pump is wired to the C1 terminal on the board and there's a C2 terminal with nothing on it. I'm assuming this would be for a second circ pump, but what I don't know is if this terminal has power at the same time as the C1 terminal. I guess I could just meter it when the existing pump comes on to see. I can't find the model number on it.
 
  #4  
Old 10-29-08, 02:32 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
No, C2 is not for a second pump.

Not sure why you don't have any wire on C2, but that is the NEUTRAL of the 120VAC supply to the (single) circ pump. USUALLY, the two Hot and Neutral power wires for the single circ would connect to C1 HOT, and C2 NEUTRAL. Your wiring scheme may pick up the neutral from the pump someplace else... or, are there a few white wires connected with a wire nut inside that box ?

Is there a number on that box you have ?

You would use a second box, with two (or three) relays inside, one for each circulator. You just run 120 into it, wire the two thermostats to the terminals, wire the circulators to the terminals, and another thermostat wire from the relay box to your existing control box.

That new relay box would be one of these, in two or three 'channel'.

Taco Switching Relay page
 
  #5  
Old 10-29-08, 02:36 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Did you say how many feet of 3/4" pipe is in the new loop ?

And, how many of those feet are 'fin-tube' ?
 
  #6  
Old 10-29-08, 06:27 PM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Will work out to around 80 feet of pipe and 14 feet fin. I decided today to go the circ route instead of zone valves. Will be simpler and probably cheaper in the end.

My only question at this point is where to place the second pump. The existing one is on the return side, so figuring I'll just tap into to the return with a flanged T at the output of the existing pump.
 
  #7  
Old 10-31-08, 07:47 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Ended up getting a Taco 007 pump (wanted a 005, but no one had one readily available) and a R845A relay. The existing aquastat controller (Honeywell) on the boiler has lost the placard, so not sure exactly what model it is, but if I'm reading the diagram right for the new relay it looks like I run from the ZC and ZP terminals on the existing control to the 1 and 4 terminals of the new relay.
 
  #8  
Old 10-31-08, 03:25 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
If your aquastat has the ZC and ZR terminals then yes, that is probably the way to wire it ... can you tell me specifically what diagram you are looking at in the Honeywell lit ?
 
  #9  
Old 11-03-08, 07:53 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
I was looking at Fig 7 of http://customer.honeywell.com/techli...0s/69-0790.pdf.

I discovered that the boiler has a 8124 on it, so the ZC and ZR terminals should be the ones used with the 845 based on what I'm gathering.

In this case the existing circ is in the return side just above the inlet to the boiler. What I came up with was a Y made up of a 1 1/4 T fitting with 1 1/4 flanges attached with short nipples. Was going to mate the T to the existing pipe going to the inlet and mate the existing circ to one side of the T and the new one to the other. Then the supply to the new zone would be done with a 1 1/4 x 1 1/4 x 3/4 T inserted into the supply line for the existing zone.
 
  #10  
Old 11-03-08, 04:17 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Pump selection ?

Would it be possible to sketch up or otherwise draw what you are thinking ? Photo of the existing setup might help in deciding how best to hook up new pump ...

You can get a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pics there, drop a link here for us to see ... linking the whole album is easiest...

Keep in mind the mounting position of the 007 *which may be a bit much of a pump for a single small zone* that you follow the directions and keep the motor axis horizontal.

Why not a Grundfos 15-58 3 speed ? You could run it on low speed ... still might pump a lot in that one zone ...

Someone else on here is the pump guru though... maybe he'll chime in with a recommendation ...
 
  #11  
Old 11-03-08, 09:00 PM
Who's Avatar
Who
Who is offline
Member
Join Date: Jan 2006
Location: San Jose
Posts: 2,175
Received 0 Votes on 0 Posts
Is that 007 returnable? If I were in your shoes I'd get a couple of Grundfos 15-58FC circs. One for the existing monoflo on speed 2 or 3 and one for the new zone on speed 1 or 2. These circs have built in flow checks. Those and some isolating flanges and you're set. With an SR-503 you're set if you ever want to add an indirect or another zone.

What's the current pump that you have for the monoflo?
 
  #12  
Old 11-04-08, 08:12 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
The existing pump is a TACO 007. I'm checking on the Grundfos availability now. I see no real point to changing out the existing pump, as there is a check valve in the existing line. The 007 I bought is returnable.

Here's a diagram of the existing and what I'm thinking of doing:

 

Last edited by NJT; 11-07-08 at 02:52 PM.
  #13  
Old 11-04-08, 08:29 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Turns out the local supply house has the 15-58FC in stock, so will be picking that up this afternoon.
 
  #14  
Old 11-07-08, 09:01 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Thinking about my diagram again, I'm wondering if it's gonna make a huge difference if I tap off after the flow control for the existing system. Ideally I would tap off prior to the flow control, but that's gonna be a lot of work... a lot!

I also came across what looks like a very good document on the B&G website that discusses zoning and the ideal ways to do it. It mentions that these days with improvements in components that the circulators should be on the supply side and not the return. They claim the whole system would operate better and air removal is easier since there's no pressure drop in the system when the pumps startup.

That being said, if it turns out that I should really tap off for my new zone prior to the existing flow control then I may as well move the circulators to the supply side since I'd have to pull apart just about all the plumbing from the flow control back to the boiler anyway.
 
  #15  
Old 11-07-08, 02:46 PM
Who's Avatar
Who
Who is offline
Member
Join Date: Jan 2006
Location: San Jose
Posts: 2,175
Received 0 Votes on 0 Posts
The rationale for supply side is that it's easier to eliminate the air from hotter water and you should pump away from tghe point of no pressure change which is the expansion tank attached to the air eliminator.

Then along comes the modcons and many need to be pumped into just to confuse everyone again... LOL
 
  #16  
Old 11-07-08, 03:02 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
jrhem, sorry... I meant to point that out to ya and it slipped my brainiac ...

That won't work like that ...

The check valve can't be on any 'common' piping. What is going to happen is that when the new zone calls for heat, and that pump starts, you will get flow in the main zone ...

I think the B&G doc that you read showed a diagram of a heating loop and the differences in the pressure around the loop ?

When you pump AWAY from the exp tank conx point, the head that the pump develops is ADDED to the system pressure, shrinking air bubbles, making it easier to remove them. As they come around the loop, the pressure decreases, the bubbles get bigger, the separator has an easier job of removing them.

If you pump TOWARD the exp tank, the head of the pump is SUBTRACTED from the system pressure ... bubbles get bigger, harder to remove, etc ...

So, while it may make the most logical sense to pipe it that way, you have to balance that with how much re-work you want to do. Or, how much you HAVE to do ... some you might even not WANT to do !

At the very least, pump AWAY from the tank connection point. That will give the most benefit ... if you HAVE to or WANT to put the pumps on the supply side, go ahead... otherwise, leave them on the return... as long as you pump away from tank ...
 
  #17  
Old 11-07-08, 09:07 PM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
So, you're saying I could leave well enough alone, add the second circ per my diagram and make sure I tap into the supply side for my second zone between the expansion tank and the flow control?
 
  #18  
Old 11-08-08, 06:16 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
I studied this thing again last night and looking at the existing system I believe it may be easier to do this...

Two Grundfos pumps (as mentioned before). T off the supply side of the boiler and put the expansion tank on the T. Above that put my two pumps on a common manifold. Run off to each zone with the appropriate size pipe.

While this sounded like a lot of work to me in the beginning, it's actually going to be easier because I can replumb the original zone in copper. In other words, the only reason it looked like a lot of work is because the existing stuff is plumbed in steel pipe and to tap off I'd have to disassemble most of it to get a T in there. If I gotta take it all apart anyway, I figure why not just do up to the pumps in threaded since it won't be much and the rest in copper.
 
  #19  
Old 11-08-08, 08:16 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
That sounds like it would work ... and while you are doing all that, stub in an extra "Justin Case" zone for future use. Ya never know ...

You could just get out yer Sawzall and cut out section of pipe between boiler and existing flow control on supply, and between boiler and existing circ on return ... Put in a tee and a union at each location and run the new zone the same way as it always was with the pumps on the return. Off the supply tee, a check valve to the new zone ... Taco SR502/503 to run the circs and call it a day. This is assuming that you have a straight section of pipe at each location to add the tee and union ...

I mean... if you have lived with the system for a while, and not felt the pain of air in the pipes ... why change the whole thing if it works OK ? Pumping away ... circs on the supply ... it's the "IN" thing it seems. But look at the millions of systems out there that are piped as yours is, and merrily chugging along all these years without a problem ...

Why not put up a few pics of the existing system ? Maybe that will inspire some more suggestions ...
 
  #20  
Old 11-09-08, 04:44 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Well, had to start this project yesterday. Turns out that moving the circs to the supply was easier with the exception of finding everything I needed. Ended up spending half the day running to this store and that gathering things. Didn't give me much time last night to work on it, but should have it finished up today.

Only problem I ran into was the thread sealer originally used had hardened and the only effective tool for removal of the old piping was the trusty Sawzall. At the boiler the stub just wasn't gonna come out, so I chopped it off about 2 inches above the boiler and then cut down the length to just shy of the boiler. Came right out after that. Did not, of course, come up with this idea for removal until after I wrecked my shoulder trying to wrench it out.

Anyway, things are going pretty well so far. Only thing that hit me before I quit working on it last night was that I should have installed flanges between the pump manifold and the boiler stub for easy removal of the whole assembly down the road. Only reason I'm not beating myself up too bad over it is because I'm replacing the boiler next year and when I do that I can just remove or cut out everything in the way and then unscrew the manifold off the stub. I'll put the flanges in then.

Sometime this morning I should have everything finished and I'll fire it all up and we'll see how it works out. Thanks to everyone for their input thus far.
 
  #21  
Old 11-10-08, 07:05 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Well, finished the plumbing and fired it up. Still have to wire up the second zone, but wanted to get the upstairs going since people do live there. Couple of threaded joints were pissing water big time. So much for that Pro Dope. Ended up taking the joints apart and putting teflon tape on them to fix the leaks. Must be those made in China fittings.

Anyway, everything is working pretty well. Again, haven't wired up the second zone yet, but my primary concern was how much hot water I'd get back into the second zone from the first. Didn't get anything to speak of. Return side of the second zone was a little warm about 5 feet away from the boiler, but by 8 feet the pipe was still cold, so things should be good.

I took a few pictures, but it was with my wife's cell phone so they didn't come out that great. I'll post pics once I get it all wired up and working.

Only thing I would have done differently is build the manifold from copper instead of threaded fittings. Most of my leaks were there. I think I may just put one together anyway to have on hand when I put in the new boiler.

Only other problem I'm having is the boiler drain valve is seeping. I was thinking before filling the system I really should change out that valve, but for whatever boneheaded reason didn't. It may stop, but I doubt it. I just hope it isn't 'glued' in there like the other fittings were.

BTW trooper, the document I was reading that talks about putting the pumps on the supply side was from the B&G site and it's called 'Zoning Made Easy - Rules of Thumb for the Non-Engineer Installer'
 
  #22  
Old 11-18-08, 08:31 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
So it's done. Works great. Here's a pic (cell phone, so not that great).

 
  #23  
Old 11-18-08, 08:39 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
From what I can see looks OK... 'cept for one thing ... from what I can tell, the expansion tank appears to be on at least a foot long pipe nipple ... I know it doesn't feel heavy, but imagine a failed, waterlogged tank ... maybe 30-40 pounds ? I believe you should add some secondary support for that nipple.
 
  #24  
Old 11-18-08, 09:21 PM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
Originally Posted by NJ Trooper View Post
From what I can see looks OK... 'cept for one thing ... from what I can tell, the expansion tank appears to be on at least a foot long pipe nipple ... I know it doesn't feel heavy, but imagine a failed, waterlogged tank ... maybe 30-40 pounds ? I believe you should add some secondary support for that nipple.
Good call. Yes, it's a 12" nipple.
 
  #25  
Old 11-18-08, 09:31 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Where did the air scoop end up ?

and the flow checks ... you maybe used the IFC pumps ?
 
  #26  
Old 11-19-08, 04:17 AM
J
Member
Thread Starter
Join Date: Oct 2005
Posts: 20
Received 0 Votes on 0 Posts
You can't see them in the picture, but from the top of the pumps the pipes run up and go left to where they connect to the existing plumbing and the added zone plumbing. Each circuit has an air scoop in those horizontal sections.

Used the Grundfos pumps with the flow check.
 
  #27  
Old 11-19-08, 06:20 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Good deal ... and good luck !
 
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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: