I’m considering a change out to a new gas modulating boiler and scrapping my 25 year old Crown CXE-4. When I installed the Crown, I put in 6 AutoMag zones, one feeding an Amtrol indirect water heater. Last year, I changed all of my zones installing Erie zone valves. Coming off my boiler I have a inch and a 1/4 line running to a horizontal header with the six, 3/4 inch Erie zone valve running off of the header. The return line is the same setup less the zones. (I wanted to add pictures of my configuration but I could not figure out how, sorry. Copy and Paste didn't work.)

The new boilers I looked at need a primary/secondary loop. So, here are a few questions I have.
1. Can I keep my zones?
2. If so, how many pumps will I need, 2?
3. How do I size my pumps? One will most likely come with/on the boiler.
4. How is the pump run on the secondary loop? Maybe the boiler is wired to accommodate that

What I’m thinking about doing is adding a piece of inch and a 1/4 copper and 2 tees to make a loop (piles are about a foot apart vertically and about 2 – 21/2 feet long) and put a circulating pump in the header by the zones. However, I was taught to put the zones on the return line. Would the pump go in that line or on supply side? My guess is the return. Any help is appreciated and if you can tell me how to post pictures here, this may make more sense.
Thanks much!... Patrick

 

Hi Patrick, welcome to the forum!

I'm sure you will get some help here, but let's start with the pics first.

To post pics, you need to set up a free account at a picture hosting site. I like Image hosting, free photo sharing & video sharing at Photobucket . Upload your pics there, and come back here and post a link to your album.

 

Thank you NJ Trooper. I just reposted this with the pictures. Thanks again.

I’m considering a change out to a new gas modulating boiler and scrapping my 25 year old Crown CXE-4. When I installed the Crown, I put in 6 AutoMag zones, one feeding an Amtrol indirect water heater. Last year, I changed all of my zones installing Erie zone valves. Coming from my boiler I have a inch and a 1/4 line running to a header with the six, 3/4 inch Erie zone valve running off of the header (left side). The supply and return line are sized and built the same, inch and a 1/4 pipe, six tee's sized to 3/4 inch for supply and return. This is a picture of my configuration.





The new boilers I looked at, I need to install a primary/secondary loop. So, here are a few questions I have.

1. Can I keep my zones?
2. If so, how many pumps will I need, 2?
3. How do I size my pumps? One will most likely come with/on the boiler.
4. How is the pump run on the secondary loop? Maybe the boiler is wired to accommodate that.

What I’m thinking about doing is adding a piece of inch and a 1/4 copper and 2 Tees to join the loops (picture below) and put a circulating pump in the header by the zones. Would the pump go in the line to the left (where the Watts ball vale is) or on the right? My guess is the left. Any help is appreciated.







I hope this makes sense and I will do my best to clarify any questions you have. And yes, that is an avocado freezer form 1974.

 

join the return header to the supply header (include two tees which is where you will inject the boiler water).
Put the pump between the air separator / expansion tank point (point of no pressure change), and the supply header.

Pump from the boiler into the Tee closest to the supply header, then return the cooler water back to the boiler thru the other tee.

Fill with water, program, and enjoy your savings.

 

Check out: Technical Menu

There is a lot of good info that may be helpful here for you.

 

In the 'technical menu', under 'modulating condensing boilers', click the first link ''primary/secondary tutorial', and pay particular attention to drawings 4 and 6.

The dimensions of the P/S tees are somewhat critical, so drawing 6 should be followed. Since you have an 'elevation change' to deal with, it would be best to do that with 45° elbows, the gentler bends pose less restriction to flow and also provide a 'smoother' flow past the P/S tees.

Whether the P/S system pump is to the left or right of the tees really doesn't matter a whole heckuva lot, as long as it's far enough from them to adhere to the dimensions given.

What you DO want to do is what we call 'PUMP AWAY'. This means that you want your air sep, and expansion tank UPSTREAM of the circ pump. Old school didn't understand this concept, (and your current setup is piped old school with the circ on the boiler return) but it is pretty important in terms of keeping a system air free. It really does help! So you might have to rearrange things a bit...

Myself would probably come straight off the return manifold 8 diameters, 1.25X8=10 inches minimum, then the tees, then 4 diameters, then the air sep and tank, then the circ, then as gently as possible angle up to meet the supply manifold.

The boiler water feed and pressure regulator should tee into the pipe between the air sep and the tank. (google WATTS RBFF for a really nice valve that makes servicing the expansion tank SO much easier!) I don't know for sure about the B&G FB8 pressure valve that you are using, but I do know that Watts wants theirs installed horizontally... yours is vertical, so keep that in mind when piping. I can't see a 'backflow preventer' in the water feed line... you want to add one of those too... (watts 9D is one make).

1. Yes, of course.
2. Yes, one for the system loop, as above, and one for the boiler loop which will probably be internal to the boiler.
3. The system loop will be fine with a 007 or equivalent.
4. I think it depends on the boiler? not a whole lot sure cuz I ain't fooled with the mod/cons... maybe TO can illustrate that point a bit... But as far as control goes, I would lose the discrete wiring for the zone valves and install a Taco ZVC for zone control. Taco has all install stuff at their website Taco-Hvac ...

Let's see... oh... you might wanna lose that Romex wiring that you currently have tied to the supply line. I wouldn't run the AC line along that hot pipe... and you don't wanna use Romex (NM) cable for that anyway... it should be metal sheathed cable (MC).

And your indirect... that will be piped differently with the mod/con also... follow the instructions in the mod/con installation for that. Basically you will be removing that piping from the supp and ret manifolds and connecting directly to fittings on boiler for the purpose...

What boilers are you considering? (hint: Triangle Tube)

 

Oh... the avocado freezer... I was hoping it was a fridge and it was stocked full of Sam Adams Octobeerfest... and for that, you would have had volunteer helpers at your door! well... at least ONE anyway! Beer 4U2

 

Any kind of zone control box would be highly recommended to look after the zone valves.
I prefer Taco as well, but Argo has one and Grundfos has a new one I think.

They look after switching on the circ on any heat call and will fire the boiler.
The Taco has plug in cards for outdoor reset and pump exercise, so if your mod con does not have built in smarts, it can be added easily.

 

Shouldn't the circ pump come after the air separator and expansion tank?

 

Uhhhh... yeah... and your point?

 

Hmm. I misunderstood "upstream". Sorry.

 

Weren't avocado appliances pretty much out of fashion by '74? We had matching harvest gold 'fridge and range - which we had painted white in around '77.

I'm waiting for one of my wife's home decorating magazines to feature retro kitchens with all those colored appliances.

 

Harvest Gold is 'out' ? and nobody told me? oh crap...

(droopy, s'ok, I unnerstan... I sometimes don't know the difference between my left, and my 'other' left)

 

ya and unfortunately the packy was out of Octoberfest. Think I had my last ones of the year tonite

 

Sorry so long for a response. Kids need/use the computer more than me. By the time I get to it, its 11:00 and time for bed.

It looks like I have a lot to think about. I believe I'll end up analyzing this thread line by line.

You are correct in that the Romex should not be set that way. The new one will be correct as I'm not that fond of keeping wire on a hot pipe. When I ran the stat wire, I used tie wraps tied to tie wraps to keep them off the heat pipe. It would be nice if they made something that could use to run wire and still make it look good.

As I read this, I will be asking questions for clarification. Hope you don't mind.

Why is it necessary or a good idea to install something for zone control? I thought this could be completed with controls on the boiler. What will this do for me?

You brought up a good point regarding the circulating pump. What I’m understanding is that the sep and expansion tank are correct but not the pump location? This boiler came with the pump mounted. If the pump was on the supply side, and then this would be correct? I think with a little reconfiguring, I can set up the piping like the picture in the technical menu drawing 4. It should not be a problem to get both headers in line and I will need a bit more room for the circ pump anyway. Would I just have to remove the elbows and add tee’s there on the supply and return line?

Why do you like the Triangle tube? I got a price e today for a SP100 Triangle tube boiler. Here is the speck sheet:
• All Triangle Boilers are Factory Tested
• Triangle Tube Limited 10 year warranty
• Stainless steel heat exchanger
• Outdoor temperature sensor
• Stainless steel burner
• Negative pressure gas valve
• 30 psi relief valve
• Flanged Grundfos UP15-58 system circulator (Triangle Solo PS60 and PS110 only)
• Drain valve
• Pressure gauge
• Condensate drain assembly
• NTC temperature sensors on the boiler supply/return and flue

What is a negative pressure gas valve?

Can you explain the math a bit? I read the information for drawing 6 several times but still not sure as what this means.

Lastly, I bought a new freezer. Hahahaaaa

 

No problem, Good Lord willin' we ain't goin' anywhere!

Not really necessary, as what you have is and has been working fine for so long now... it's more of a luxury, with the bonus that it is easier to troubleshoot, easier to wire, and LOOKS better (if that's important to you!) Those panels basically will lose all the 'rat's nest' wiring. The t'stats will all wire to their own terminals, the zone valves to their own terminals.

Take a look at this PDF for an overview of product:

http://www.taco-hvac.com/uploads/Fil...ry/100-5.0.pdf

Now, you WILL need at the least, a relay box to run the SYSTEM circulator (the one on the P/S loop), as this circ is not controlled by the boiler itself. The Boiler will only control it's own circ, the one on the boiler loop feeding the tees.

Take a read through the install manual:

http://www.triangletube.com/document...0%20Manual.pdf

Notice Fig. 21 on manual page 34 (PDF page 40?)

This will show that relay I'm talking about.

Right now, your endswitches are wired to the aquastat on your Crown. That aquastat operates a relay that 1.)fires the burner, and 2.) operates the circ.

The new boiler needs a 'dry' (no voltage) contact to operate. So, yeah, you could wire the existing endswitch wiring to the new boiler, but there is no way to run the system circ then. That's where the DOUBLE POLE relay in Fig. 21 comes in. The zone valves switch the relay, one pole turns on the circ, the other pole turns on the boiler.

OK, so yer gonna spend say $50 to $75 or so on that single relay, right? Why not go just a wee bit more... and add the zone valve control panel to the shopping list. This panel will include everything you need to both run the system circ, and fire the boiler. It also includes the 24VAC transformer for the valves.

ZVC406-3 - Taco ZVC406-3 - 6 Zone Valve Control Module with Priority

This one is for 6 zones, and for some reason (typo maybe?) it is cheaper than the one for the 4 zones...

Ummmm... sorta, not exactly...

The only reason that pump was there on the return is because it was a good place for the manufacturer to bolt it for shipment. But, it's a long story as to how and why the circs were traditionally mounted on the return side... won't go into that now...

Move the circ to the supply side... no, not if it was pumping TOWARD the expansion tank. The proper location for the circ is simply PUMPING AWAY from the expansion tank. On your existing system, this would be, yes, on the supply side, but in between your expansion tank and your supply manifold.

Theoretically, it could be on the return side, IF the expansion tank was also, and was pumping away from the tank. But, there are OTHER reasons for placing it on the supply side, which I won't go into now either...

You don't need to do EXACTLY as that drawing... it's conceptual only. Follow in your mind... in order, from left to right:

Your existing return manifold, closely spaced tees, your air sep and exptank, your system circ, your supply manifold.

The dimensions in the drawing are pipe diameters... example, you are using 1-1/4" pipe. 8D means 8 X 1-1/4, or 10". Same size pipe, the distance between the tees is AS CLOSE AS PRACTICAL, but NOT MORE THAN 4 pipe diameters... in this example, 4 X 1-1/4, or 5" between the centerline of the tees. Then on the right side, minimum of 4 diameters before any other components like an elbow, air sep, etc...

So, as in my earlier post, off the right side of your return manifold with at least a 10" pipe, then your tees properly spaced, then a minimum 5" pipe, then your air sep and tank, then your system pump, and into your supply manifold.

The minimum dimensions are intended to keep the flow smooth past the tees, not turbulent, and minimize the PRESSURE DROP BETWEEN THE TEES... that is the importance here.

Because Xiphias does! Seriously, I believe it's about the highest regarded mod/con... seems to have the best design/support/reliability out there.

I have no idea, I'm not a 'gas guy'.

That's great! but is the FRIDGE well stocked with beer? THAT is the importance here!

 

Several reasons to prefer the Triangle Tube to the others, but they all basically boil down to this - much better heat exchanger (hx) design.

There are many different hx designs out there. They are all either stainless steel or aluminum. Personally, I wouldn't use an Al hx, while they do work well, they are very sensitive to water chemistry issues, and can fail if your water isn't "just right". I'd stick to SS.

Most SS mod/cons seem to use the same hx - the one made by Giannoni. This hx is basically a coil, made of flattened SS tube, placed inside a burner can, with flames coming from the side at the hx. This has several problems:

1) The small cross-section of the tube results in high resistance to flow.

2) For the same reason, the tubes are easily clogged by small particles.

3) Condensate forming in the can can splash on the side-mounted burners, disrupting the flame and causing soot buildup on the hx.

4) The hx needs to be cleaned frequently (annual service is a must), as it rapidly looses efficiency when the soot is allowed to build up.

5) Very low water volume in the boiler means the system has little thermal mass, leading to more short-cycling.

By comparison, the TT hx is a can through which water flows (baffles cause it to move in appropriate ways), with flame pipes running through the can. The burner is on top of the can. The pipes are oriented vertically.

This means that the condensate doesn't splash on the burner (burner is above), but instead washes down the insides of the flame pipes, washing away the soot. The water travels through the large can, which gives low resistance and no small passages to be clogged. The water volume is much more (though nowhere near what a cast-iron boiler contains), so less short-cycling is present.

As a result, the TT boiler is much more reliable, and requires far less maintenance. Though it should still be checked on a regular basis by a trained technician, not being serviced religiously won't kill it like a Giannoni-based boiler.