Need sanity check on oil boiler installation


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Old 09-15-09, 07:39 PM
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Need sanity check on oil boiler installation

Hello! I've decided to get a peerless wbv-03 (mainly due to clearance and code limitations) repalcement unit, and am wrapping up details for the install. I'm working against a lot of conflicting informaition, so I'm hoping I can solicit some input on this as is it getting confusing for me:

1) The boiler I'm getting has a (taco 007 I think) circulator packaged/pre-installed on the return. Is that OK? I'm being told the circulator should always be on the supply, but the boiler installation manual documents it as being on the return.

2) My zone valves are currently on the supply side, and were known to be working well. I've been told that zone valves must be on the return side. I just wanted to leave the existing supply and return lines as-is and pipe the new boiler up. Boiler docs don't specify a preference.

3) I have very little horizontal distance to work with. I plan on coming out the supply to a T for a (code required) low-water cutoff, followed by a votrex air-remover piped to the existing supply-side zone valves. The cold water input will be piped up to a T in the expansion tank line.

4) The boiler docs caution about return temp under 150F and condensing. I'm looking at the tekmar 260 outdoor reset, and for fin-tube baseboard the min temp setting is 140F. So what does this mean? Do I override the tekmar for a 150F min, or pipe in a supply bypass to keep the boiler warm? How can I automate a supply bypass to avoid manual intervention?

Thanks -- all of you guys have been a big help already!
 
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Old 09-15-09, 08:16 PM
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1) If they want the circulator on the return (and I don't see in the manual that they truly require it), fine. The important relationship is where the expansion tank and water fill connection are made relative to the circulator. That point of connection should be on the inlet (upstream) side of the circulator. Dan Holohan's wonderful book 'Pumping Away' talks about why.

2) You were told wrong. Zone valves are most often on the supply side. Among other reasons for that position is that when closed they prevent heat migration through the system.

3) You should take a look at some good piping diagrams. For example, the Burnham MPO manual shows a simple, clean way to pipe their boiler that is industry-typical and would work fine with the wbv-03.

http://burnham.com/pdf/MPO_io.pdf

see figure 18B on page 32. If you want to leave the circulator on the return, just move the supply water/expansion tank connection to be on the inlet side of the circulator as shown in that figure.

The figure in the MPO I&O is very similar (even essentially identical) to the GAMA/IBR manual that Peerless says the installer should follow for water piping. That is, circ on the supply pumping away from the expansion tank, and zone valves on a supply manifold. (And go ahead and ask any installer if they have that manual on the truck. Most of them don't.)

A note on the Taco Vortex -- the air vent in the cast iron vortex housing is just a standard Taco vent. The issue with those is that when they start to leak (which all vents do eventually), the water ponds in the vortex housing and can rot out without your ever really seeing it until it fails big-time. In the Taco line, either their standard air separator or the 4900 series would be a better choice. Or a Spirovent or similar. If you're tight for piping space the 4900 and Spiro have no minimum straight inlet pipe requirement like the older styles.

4) 150F is a very conservative number. For oil-fired appliances, condensing really starts to occur much lower -- like 115F. Point being that you can have lower return temps than 150F so long as you get decent runtimes and the boiler gets good and hot. Going with the smallest boiler relative to the heat loss is a big part of how you do that; so is having a bypass. Peerless wants you to provide boiler protection by using a bypass. Fine. Use the approach in the MPO manual. Simple, clean and effective. The bypass will be a set once and done arrangement.

You can reduce the tekmar boil min to probably around 120 once you see how the boiler comes up to temperature with the bypass.

The tekmar 260 really likes to have the indoor sensor. Not essential, but very nice to have. If you can find a good 'thermally average' place in the house, stick it there.

You've done a good bit of homework. Have at it and good luck.
 
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Old 09-15-09, 09:07 PM
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Thank you Xiphias ... every bit of information I can get on this is truly appreciated!

Putting the expansion tank on the supply side, and the circulator next to the return technically would be putting it on the pump inlet (but very far away). That's how my current boiler is now. If it is optimal to have the air separator and expansion tank close to the circulator, then I could move the circ to the supply side .... I think I have enough room -- and doing that might make the return side retrofit to my existing plumbing easier. But, I'll read over the whole MPO piping directions tomorrow morning.

I could get the tekmar indoor sensor, but a thermally average location would be a challenge. My house is a bi-level with no real separation between up/down stairs zones, so naturally most of the heat rises up. The foyer might be too drafty, and downstairs too cool ... perhaps at the top of the stair case it would work.

Thanks much! I'm sure I'll need to post more questions as my parts start to come in.
 
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Old 09-16-09, 04:22 AM
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Originally Posted by JamesNJ View Post
Putting the expansion tank on the supply side, and the circulator next to the return technically would be putting it on the pump inlet (but very far away). That's how my current boiler is now. If it is optimal to have the air separator and expansion tank close to the circulator, then I could move the circ to the supply side
Exp tank on supply and pump on return is not pumping away. "Very far away" is 'pumping toward'.

It is optimal to have the expansion tank and supply water connections close to the inlet side of the circulator, regardless of where the circulator is.

There is nothing magic about the air separator location. It is typically on the supply side because that's where the water is hottest and thus the oxygen in the water most liberated from the water and thereby easily scavenged by the air separator.

Manufacturers often show the exp tank and supply connecting to the base of the air separator simply because all or nearly all air separators come with a convenient 1/2" port. That means you don't need another tee somewhere to cut in the exp tank and fill connection.

You can have a separator on the supply and the exp tank fill / circ on the return. That will work fine. Again, the key is to have those components in the right relationship to each other relative to the flow through the system.
 
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Old 09-16-09, 01:17 PM
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James NJ, trust what Xiphias is telling you about the point of connection of the expansion tank in regard to the circulator. He's got a lot of experience with this in the real world.
 
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Old 09-16-09, 05:56 PM
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I read the burnham docs and things seem logical. Thinking about my application, I could probably pipe the expansion tank and circulator on either side, although I'm thinking that the supply side will probably make for neater plumbing and easier access for cleaning. But I'll need to plan it out a little more.

The MPO docs show the bypass line and valves ... but is there a suggested type of valve used? I would just as soon assume that all these valves can be ball valves, but then I'm thinking that maybe the bypass needs to be something with a finer level of control?

I see a single purge valve diagramed at a high-point in the supply start. On my existing boiler I don't have one there now, but I do have a purge on each of the individual return lines. Is it better to have more purge valves, or is only one at the start of the supply necessary?

Are check valves required (or suggested) anywhere in the system other than the cold (house supply) input line?

I don't know much about expansion tanks ... is there a rule of thumb for sizing or a one-size-fits all?

Also, the output for the hot water package is 1.5 NPT, I'm assuming that my small 2 zone house can use smaller piping. What is typical piping between supply and zone valves? I think the included circulator is 1.25".

The taco 49xxx and spirovent vjr air separators are expensive! But, I don't have 18" horizontal to play with so I may not have a choice.

Thanks!
 

Last edited by JamesNJ; 09-16-09 at 06:57 PM.
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Old 09-16-09, 08:17 PM
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Averaging sensors

By using 4 indoor sensors in a bridge you can average 2 levels.
But 2 sensors on each level and wire them to form a diamond (a square really but every one draws it as a diamond).
This actually puts the sensors in a series parrallel relationship that will form an average over the 4 sensors. From what I remember, they call it a wheatstone bridge.
There should be a bulletin and / or a wiring diagram for such a circuit on the Tekmar Controls website.

If you don't find it let me know and I will find / make a drawing.
 
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Old 09-16-09, 09:07 PM
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TO, you rock. Found it. Wow that is the coolest thing. I gotta try that. Cannot believe I've never seen that bulletin.

http://tekmarcontrols.com/sb/sb018.pdf

Thanks!

James, answers to some of your questions.

The single purge on supply is a principle discussed in Dan Holohan's 'Pumping Away.' Since it sounds like you are DIYing this install, that is a book well worth getting. See if you library has it, if not google it and you'll find the place to order. $25 very well spent.

For a zone valve system, no additional checks are needed on the distribution loops.

The bypass valve should probably be a very-good quality globe valve. Go to the supply house and get one with a real teflon seat and some beef to it. Not the cheapie rubber seat valve from the bin at the home center.

Valves and drains on the zones are good for isolation for servicing. Once you read Holohan, you will see how the single purge point works beautifully and simply.

Expansion tank sizing is based on the volume of water in the system. I think the Amtrol website has a sizing guide and table or link to figuring how many gallons of water in different diameter pipes.

The piping size coming out of the boiler and for the header can be full size, but you could also probably go down to 1" without issue. I defer to the more knowledgeable folks on this point. Tee-ing off the header to the zones can use a side-port reducing tee (or whatever they're really called...) to get you the size needed for the zone valve. If you're doing an indirect heater, pipe that in 1" right to it.

I have a 4900 air sep, and have seen a demo model that was cut in half. It is a well-engineered piece of equipment, built like a tank. Works great and will last a very long time.
 
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Old 09-18-09, 11:20 AM
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Thanks!

I have a question about the bypass pipe size. From the boiler, the supply-side is 1.5" and the return is 1.25". The burnham doc shows their complete bypass loop being at 1.5". I believe (but I need to measure) that my existing supply and return manifolds are 1". I don't actually have the boiler package just yet, but I believe the supplied pump will have 1.25" mounting flanges

So, my question is what pipe size to make the loop. I'm thinking that I will probably be reducing this to 1" anyway, so perhaps I should come immediately out of the supply with a 1" reducer, pipe the shutoff valves and bypass loop with 1". The supply will tee off to feed the air scoop, expansion tank, circulator, and supply manifold with zones. The return will come in at 1" with a T for the bypass, 1" to cutoff valve, then with a 1"-1.25" converter back into the boiler.

Sound sane or am I not thinking about this correctly?

Thanks for the book suggestion ... I've ordered it, but it is getting cold here in the NE and I have to move quickly. So, I feel like I'm in tired-school-kid tantrum mode where I want all the answers to my homework without understanding the lesson I would love to understand all of these points, but I have to wrap this whole thing up in about a week or so.

Thanks! I really appreciate all of the help!
 
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Old 09-18-09, 05:35 PM
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One inch piping will be fine, and easier to find a threading machine. I'd still be tempted to open it up to 1.25" for the air eliminator but I'm a tweaker.
 
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Old 09-18-09, 05:50 PM
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What Who said. 1" will be fine.
 
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Old 09-18-09, 07:46 PM
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Threading machine? I was hoping to sweat it all around in copper -- hopefully that will be fine. I don't think I have any materials or access to a black pipe threading machine, and will probably reduce and pipe as much in copper that I can.

I think some of the doo-dads like the air eliminator start to go up in price dramatically after 1.25". I'll look and see what I can do, but if I can do things in 1.25" copper, it shouldn't be too bad as my run is pretty short.

Thanks for the help! My boiler, teckmar, and field controls OVD are being moved to the supply house, and this weekend I'll add to it the air eliminator, expansion tank, low water cutoff and a few other misc things.
 
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Old 09-18-09, 08:07 PM
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Fired at .60 is 75K DOE so you would be fine with the 1". Copper is OK but black pipe nipple support better on the near boiler piping.
 
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Old 09-20-09, 07:24 PM
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Hello all, have some addditional questions on my project ....

The inspector said I need a low water cutoff control. Taco has some, but there are 2 basic models I see LNA0243S-1 (24v) and LNA1203S-1 (120v). Taco's site seems to show a different model with a remote sensor, but I haven't found a place that has these. A remote probe would be easier for me to deal with, but I could probably fit the standard one on. Which voltage is better to get, or does it not matter? I think wiring the main 120v for the boiler to this thing would be inconvenient in my application, I'm assuming that I can just use the 24v to interrupt the boiler call for heat? But then again maybe it is better to cut off 120v to prevent the low-temp limit from firing on? Or any other make/model suggestions?

Also, my boiler doesn't seem to have any port to install this on, so can I assume I can just Tee off somewhere on the supply side?

I also need some kind of back-flow preventer with blow-off for the cold house line (to prevent boiler water from siphoning into drinking water). Any suggestions here? I was able for find some very expensive alien-technology looking contraptions, maybe there is something simpler/cheaper?

Is there anything special to know about the pressure balance check valve (bell shaped thing) on the cold water make-up?

Finally is there a port on the Taco air eliminator 49-100T-1 (1" fitting) for the expansion tank, or will I need a tee to pipe the expansion tank in before the pump?

Thanks!
 
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Old 09-21-09, 07:28 AM
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You can mount the expansion tank on the bottom of the Taco air separator.There should be a 1/2" tapping on the bottom of the 4900.
The LWCO should be a 120v model for oil and kill the power to everything. Run a wire from the line voltage through the LWCO and then to the aquastat L1. The probe needs to be mounted above the boiler (within 18") in the piping as it is a water boiler not a steam boiler. Steam boiler LWCO's are mounted in the boiler.
Back flow preventer's are available at any distributor and on-line.
Is there anything special to know about the pressure balance check valve (bell shaped thing) on the cold water make-up
?
If you are referring to the Pressure reducing valve it should be factory adjusted to 12 psi, good for up to a two story installation, and needs to feed into the pipe between the expansion tank and the system. This is called the area of no pressure change.
 
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Old 09-21-09, 10:07 AM
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Thanks, that helps ... sorry if these are real basic questions, but I'm in the final throws of getting everything I need.

I think I can mount the LWCO in a T off of the manifold that will branch out to the zone valves. That would be a very accessible area and make my life easier. It will probably be less than 12" from top of boiler, but I can adjust the piping as needed. I'll find a way to make the 120v wiring work.

Thanks!
 
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Old 09-22-09, 02:57 PM
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Hello! Sorry, hopefully a simple question ...

The peerless wbv comes pre-packaged with the circulator on the return, and I'm trying to work out how to locate it onto the supply. If this really not necessary let me know and I'll put the expansion tank on the inlet of the return-side pump.

But assuming I move the pump to the supply .... I believe the included pump has flanges to mate with the 1.25" return. Right now, I'm planning on coming off of the 1.5" supply NPT directly to a 1" reducer and then manifold three .75" branches to my zones (and possibly a 1" branch for future priority DHW).

So for placing the pump on the supply side, can I just use reducers on both sides to put a 1.25" flange pump into a 1" line?

Hopefully I've explained that clearly. Thanks in advance!
 
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Old 09-22-09, 06:30 PM
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You could but if space is an issue I would buy 1" flanges for the pump. They are inexpensive.
 
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Old 09-24-09, 05:48 PM
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I picked up the boiler today! Looks new and shiny.

I *thought* that the package would come with blackpipe, but it doesn't, so I'll be getting my own.

Question -- other than putting an NPT stub on the supply and return, do I actually need blackpipe anywhere else? Could I simply buy a 6" piece for each side, and then immediately use a reducer to 1" and pipe everything else up in copper? Rbeck, I know you mentioned that having blackpipe near the boiler was better for support ... but other than that, if my copper is well supported is there any other reason to use blackpipe?

Mainly I'm asking because of my space limitations ... minimizing the blackpipe (especially on the return) will make routing things easier, and I think I have plenty of areas that I can put supports into.

Thanks! I'll be hitting the local plumbing supply places this Saturday for the rest of pieces I need, next week is cutting the walls, extracting the ancient hulk, and piping in the new one. All you guys are awesome, thanks for the help.
 
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Old 09-24-09, 06:00 PM
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Hmm, you know I may need to re-think that .... I didn't realize just how heavy a taco 007 was .... it is almost all cast iron. I would have to support this with some hefty brackets from the ceiling if I put it on the supply with all copper.

There just isn't enough room on the top for me to pipe blackpipe and the circulator. But a bracket with some threaded rod may do the trick.

Anyway, let me know if I can get away with little or not blackpipe at all ... thanks!
 
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Old 09-28-09, 08:21 PM
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What is the pro/con of mounting the circulator on the return vs. the supply?

I would like to mount it on the supply, but the taco 007 is a heavy thing that I don't quite think I can fit or support properly given my space limitations.

Here is a picture of the boiler (bottom 'hot water' package): WBV
I need to use top-flue.

To put this on the supply, I would have to bend around the flue and place the circulator either behind the unit or somewhere on the right side after it wraps around the flue. The positive here is that I have full access to the left side, and about 5-7" on the back. So, the pump would not be inaccessible, but probably would require taking out the flue to service.

The suggested configuration is to use blackpipe out the return to support the weight of the taco. In this configuration, I could lengthen the short horizontal pipe and shorten the vertical segment without trouble. The pump would then be in front and easier to maintain.

It might make more sense to me after I get the old hulk out and the new smaller unit in. It might be possible to screw a metal bracket to the back wall to support the taco. If I keep my lengths tight between the supply, air vent (spirovent) and taco it could work.

Just looking for some ideas ... thanks ....
 
 

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