# Plumbing diagram comments?



## SIERRADMAX (Dec 2, 2012)

Econoburn is going into the basement this afternoon and I'll begin plumbing this week. Looking for feedback before I start threading/sweating pipe. Thanks


----------



## henfruit (Dec 2, 2012)

NIce drawing,Yours or econoburns?


----------



## BoilerMan (Dec 2, 2012)

You don't need two seperate feed water setups, your existing one should be fine.

TS


----------



## BravoWhiskey (Dec 2, 2012)

SIERRADMAX said:


> Econoburn is going into the basement this afternoon and I'll begin plumbing this week. Looking for feedback before I start threading/sweating pipe. Thanks


Maybe I'm not seeing it right, but it looks like to me that when one, the other, or both the pumps are running the water goes around the circuit above the oil boiler and there is nothing to cause the water to go through the zone valves and loads.  Simple and effective would be to feed hot from wood boiler into supply side of oil boiler and draw return to wood boiler from return side of oil boiler and leave the existing oil boiler pump and circuits alone.  Only downside would be that the oil boiler would be hot all the time and you could lose heat up the flue if the oil boiler is susceptible to that.


----------



## SIERRADMAX (Dec 2, 2012)

BravoWhiskey said:


> Maybe I'm not seeing it right, but it looks like to me that when one, the other, or both the pumps are running the water goes around the circuit above the oil boiler and there is nothing to cause the water to go through the zone valves and loads. Simple and effective would be to feed hot from wood boiler into supply side of oil boiler and draw return to wood boiler from return side of oil boiler and leave the existing oil boiler pump and circuits alone. Only downside would be that the oil boiler would be hot all the time and you could lose heat up the flue if the oil boiler is susceptible to that.


 
It's my drawing. I see the problem. The circulator has to be on the supply side providing suction to the zones in order for the check valve to close. Do both circulators have to be identical in order for the swing check to fully close?


----------



## Bob Rohr (Dec 2, 2012)

SIERRADMAX said:


> It's my drawing. I see the problem. The circulator has to be on the supply side providing suction to the zones in order for the check valve to close. Do both circulators have to be identical in order for the swing check to fully close?


 

With the boilers in Patallal you don'r need to connect the S&R, supply and return, at the right side of the drawing.


----------



## BravoWhiskey (Dec 2, 2012)

SIERRADMAX said:


> It's my drawing. I see the problem. The circulator has to be on the supply side providing suction to the zones in order for the check valve to close. Do both circulators have to be identical in order for the swing check to fully close?


 
If it's not a problem to keep the the oil boiler hot all the time with the wood boiler all you have to do is run the supply from the wood boiler to the supply side of the oil boiler and likewise the return to the wood boiler hooks in somewhere on the return side of the oil boiler. If you need to avoid keeping the oil boiler hot all the time, here's the classic two boiler system, except in your case you would have a single load circulator and zone valves instead of the multiple circulators.


----------



## SIERRADMAX (Dec 2, 2012)

I think I got it now. I apologize for my design over the oil boiler. I'm trying to invision how it needs to be plumbed and that is how the existing plumbing is orientated. I have more room in my existing plumbing to install a 2nd return header in lieu of the supply. How does this look?


----------



## BravoWhiskey (Dec 2, 2012)

SIERRADMAX said:


> I think I got it now. I apologize for my design over the oil boiler. I'm trying to invision how it needs to be plumbed and that is how the existing plumbing is orientated. I have more room in my existing plumbing to install a 2nd return header in lieu of the supply. How does this look?


I'm pretty sure that's essentially the same as the one above that was borrowed from Tarm, and it should do what you want.  I think it is important that they set it up so the wood boiler can circulate freely even when there is no load which should help avoid short cycling. Note that until the wood boiler is up to speed the load circulator can push water through the oil boiler, probably not a problem but you may want to think through how that affects your control strategy.


----------



## Bob Rohr (Dec 2, 2012)

SIERRADMAX said:


> I think I got it now. I apologize for my design over the oil boiler. I'm trying to invision how it needs to be plumbed and that is how the existing plumbing is orientated. I have more room in my existing plumbing to install a 2nd return header in lieu of the supply. How does this look?


 

You have the Econoburn piped as a primary loop, if in fact the red/ blue lines connect at the right hand side of the drawing? If you are zoning with zone valves there in no means for the flow to go to the zones. Just disconnect the red to blue line 

The Tarm drawing shows pumps on the zones to move the flow, although they have the boiler pump and the zone pumps in series which will double the head when they both run, really no need to do that. The pump with or on the Themovar should have enough capacity to flow the boiler and the zones.


----------



## SIERRADMAX (Dec 3, 2012)

Bob, doesn't that diagram force Hot water through the oil boiler when no zone is open? Won't it continiously circulate that way even if a zone opens?


----------



## Bob Rohr (Dec 3, 2012)

SIERRADMAX said:


> Bob, doesn't that diagram force Hot water through the oil boiler when no zone is open? Won't it continiously circulate that way even if a zone opens?


 

You do need some swing checks in the piping to prevent un-wanted flow.  And expansion and fill valve.  Also if you ever plan on adding a buffer, you would tie in the second boiler downstream from that.  Fig. 6-14 is close, just eliminate the hydro-separator and add the zone valves to the header

Some good reading regarding series, parallel and separator piping in this journal     http://www.caleffi.us/en_US/caleffi/Details/Magazines/pdf/idronics_10_us.pdf


----------



## BravoWhiskey (Dec 3, 2012)

Bob Rohr said:


> . Fig. 6-14 is close, just eliminate the hydro-separator and add the zone valves to the header


If hydro separator is eliminated, and  if no load, then flow through wood boiler stops as soon as return mix valve reaches setpoint.  The Tarm design prevents this problem.  Fig 14 with hydro separtor would work well.


----------



## Bob Rohr (Dec 3, 2012)

BravoWhiskey said:


> If hydro separator is eliminated, and if no load, then flow through wood boiler stops as soon as return mix valve reaches setpoint. The Tarm design prevents this problem. Fig 14 with hydro separtor would work well.


 

Good point, and it could provide some overheat dump protection if you leave the piping and separator uninsulated.


----------



## SIERRADMAX (Dec 3, 2012)

BravoWhiskey said:


> If hydro separator is eliminated, and if no load, then flow through wood boiler stops as soon as return mix valve reaches setpoint. The Tarm design prevents this problem. Fig 14 with hydro separtor would work well.


 
Correct me if I'm wrong, but doesn't the wood circ require constant circulation? Even when the mixing valve has reached it's setpoint? Hence the need for a primary loop? My revised diagram is similar to figure 14 with the exception of a loading unit in lieu of a mixing valve/circulator. I'm not ready to fund that kind of unit.



BravoWhiskey said:


> I'm pretty sure that's essentially the same as the one above that was borrowed from Tarm, and it should do what you want. I think it is important that they set it up so the wood boiler can circulate freely even when there is no load which should help avoid short cycling. Note that until the wood boiler is up to speed the load circulator can push water through the oil boiler, probably not a problem but you may want to think through how that affects your control strategy.


 
Doesn't the check valve in the supply of the oil boiler prevent this?


----------



## Bob Rohr (Dec 3, 2012)

SIERRADMAX said:


> Correct me if I'm wrong, but doesn't the wood circ require constant circulation? Even when the mixing valve has reached it's setpoint? Hence the need for a primary loop? My revised diagram is similar to figure 14 with the exception of a loading unit in lieu of a mixing valve/circulator. I'm not ready to fund that kind of unit.
> 
> 
> 
> Doesn't the check valve in the supply of the oil boiler prevent this?


 

  The pump on the wood boiler only needs to run if the boiler is up to temperature.  I fire my pump/ mix valve assembly when the boiler reaches 140F, off at 130F.  No need or reason to run that pump continously, especially after the fire burns out.

Best method is a buffer or storage, then  the "tank" not the building becomes the load that the boiler sees.the sensor to run the boiler pump.  I think it can be a big challange to run a wood boiler without some storage, especially on a multi zoned system. 

To have a primary/ secondary piping the pumps are connected via closely spaced tees, and you need a pump in the primary loop.


----------



## mikefrommaine (Dec 3, 2012)

Bob Rohr said:


> You have the Econoburn piped as a primary loop, if in fact the red/ blue lines connect at the right hand side of the drawing? If you are zoning with zone valves there in no means for the flow to go to the zones. Just disconnect the red to blue line
> 
> The Tarm drawing shows pumps on the zones to move the flow, although they have the boiler pump and the zone pumps in series which will double the head when they both run, really no need to do that. The pump with or on the Themovar should have enough capacity to flow the boiler and the zones.



In this diagram what happens when the wood boiler is at temp and no zones are calling for heat? P1 would be running but it has nowhere to pump too, right?

Couldnt you connect the supply and return headers to creat a primary loop for wood boiler. Basically what the op originally posted... That then creates a situation where the zones don't get enough bc the water will flow through the oil boiler. The tarm diagram uses pumps to overcome this...

How about connecting the headers but also add another zone valve between the headers that is only open when there are no zones calling for heat. That way when there is a call for heat the new zone valve closes and directs the flow through the zones. And allows p1 to circulate water through the primary loop when there is no call for heat.


----------



## SIERRADMAX (Dec 4, 2012)

mikefrommaine said:


> In this diagram what happens when the wood boiler is at temp and no zones are calling for heat? P1 would be running but it has nowhere to pump too, right?
> 
> Couldnt you connect the supply and return headers to creat a primary loop for wood boiler. Basically what the op originally posted... That then creates a situation where the zones don't get enough bc the water will flow through the oil boiler. The tarm diagram uses pumps to overcome this...
> 
> How about connecting the headers but also add another zone valve between the headers that is only open when there are no zones calling for heat. That way when there is a call for heat the new zone valve closes and directs the flow through the zones. And allows p1 to circulate water through the primary loop when there is no call for heat.


 
Would this be a normally open zone valve?


----------



## mikefrommaine (Dec 4, 2012)

SIERRADMAX said:


> Would this be a normally open zone valve?


Thats what I was thinking. Maybe control it with the isolated end switches If you have something like a taco sr control.


----------



## Bob Rohr (Dec 4, 2012)

mikefrommaine said:


> Thats what I was thinking. Maybe control it with the isolated end switches If you have something like a taco sr control.


 

A PAB pressure activated bypass valve could be used also, as the zone close down this valve "sheds" flow back to the return.  no need for a zone valve or a electric accuator.e


----------



## mikefrommaine (Dec 4, 2012)

The pab sounds even better, no power and no wiring. Simple is good.


----------



## SIERRADMAX (Dec 7, 2012)

I think I hve the diagram finalized.

I'll use Econoburn's factory leads for the primary circulator (p2 on the drawing). This circulator will turn on with boiler @ 150. I have a honeywell 8148 aquastat relay now controlling the oil boiler. I'll remount this in the supply header after the oil boiler manifold and before the first zone branch. When a thermostat calls for heat, the zone opens and relays to P1 to circulate water to the zone. Theoretically, because HW is flowing, it shouldn't trigger the oil boiler to fire. I have to look into this and possibly adjust the settings. After water falls below 150, P2 shuts down and the oil boiler takes over normal operation. Any comments?

Do I need another make-up water line for the Econoburn?
Do I need another expansion tank? Probably adding another 60 gallons of water. Haven't done the math.


----------



## ewdudley (Dec 7, 2012)

SIERRADMAX said:


> I think I hve the diagram finalized.
> 
> I'll use Econoburn's factory leads for the primary circulator (p2 on the drawing). This circulator will turn on with boiler @ 150. I have a honeywell 8148 aquastat relay now controlling the oil boiler. I'll remount this in the supply header after the oil boiler manifold and before the first zone branch. When a thermostat calls for heat, the zone opens and relays to P1 to circulate water to the zone. Theoretically, because HW is flowing, it shouldn't trigger the oil boiler to fire. I have to look into this and possibly adjust the settings. After water falls below 150, P2 shuts down and the oil boiler takes over normal operation. Any comments?
> 
> ...



Looking good.  However by the book you might want to review the L8148 relocation.  The failure mode effect of a P1 failure or a zone valve failed-shut state might result in the L8148 not being able to see high limit.  You might prefer to add another aquastat in series and leave the boiler jacket aquastat alone.


----------



## SIERRADMAX (Dec 7, 2012)

my concern is the current 8148's location. It's mounted in the supply manifold a good 2' below the supply header. I don't know if this will see sufficient temps from the primary loop and prevent the oil boiler from firing.


----------



## ewdudley (Dec 7, 2012)

SIERRADMAX said:


> my concern is the current 8148's location. It's mounted in the supply manifold a good 2' below the supply header. I don't know if this will see sufficient temps from the primary loop and prevent the oil boiler from firing.


Right, I'm saying to do it right you need two aquastats.  The L8148 on the oil boiler supply  should stay there as the boiler high-limit and failsafe, and another one to generate a call-for-heat to the oil boiler.  If P1 fails the boiler has no high-limit and could sit there blowing steam for as long as make-up water is available.

Edit:  Also it looks like the oil boiler would cycle on and off the 150 degF setpoint according to the supply manifold temperature.  More often the aquastat that enables the oil boiler is placed somewhere that senses the presence of wood boiler heat.


----------



## SIERRADMAX (Dec 7, 2012)

On a side note, My oil boilers supply manifold does have a L4006E high limit aquastat (I'm assuming as a failsafe?) Can't I adjust the L8148 to 140 degF setpoint? Then, it will always see 150 degF + water whenever P2 is circulating and not fire the oil burner?

Sorry for all the questions.. Still learning this stuff.


----------



## SIERRADMAX (Dec 7, 2012)

Nevermind, I won't be able to do that with a L4006E. It's a push button reset. I would be resetting everytime the oil burner turns on and gets to temp.


----------



## ewdudley (Dec 7, 2012)

SIERRADMAX said:


> On a side note, My oil boilers supply manifold does have a L4006E high limit aquastat (I'm assuming as a failsafe?) Can't I adjust the L8148 to 140 degF setpoint? Then, it will always see 150 degF + water whenever P2 is circulating and not fire the oil burner?
> 
> Sorry for all the questions.. Still learning this stuff.


Sorry here for causing confusion,  my oil boiler has a single aquastat that serves as the high limit and failsafe, If you have a separate L4006 then you're good to go for safety.

But if you use the relocated L8148 to turn the oil boiler on, it's going to turn the oil boiler right back off again when the oil boiler heats the supply manifold up to 160 (or whatever the hysteresis is).  What many do is to have a open-on-rise contact at the wood boiler or at the top of storage that disables the oil boiler.  When the wood boiler (or storage as the case may be) gets cool the contact closes and the oil boiler operates normally.  It can be as simple as snap disk thermostat on the supply line of the wood boiler that you route the boiler T-T signal through.


----------



## SIERRADMAX (Dec 7, 2012)

I remember seeing those.  so simple, then I CAN leave the L8148 in it's place....


----------



## SIERRADMAX (Dec 7, 2012)

Found these....
http://www.senasys.com/shop/products-page/1-inch-diameter-pipe-mount/2570l211/
I'd assume if P2 starts at 150 degF, it would be best suited to choose the open @ 160, close @ 150 thermal switch?


----------



## ewdudley (Dec 7, 2012)

SIERRADMAX said:


> Found these....
> http://www.senasys.com/shop/products-page/1-inch-diameter-pipe-mount/2570l211/
> I'd assume if P2 starts at 150 degF, it would be best suited to choose the open @ 160, close @ 150 thermal switch?


I guess the switchover temperature would depend mostly on your goal, which could be anywhere from 'seamless comfort' down to 'quit your whining, at least the pipes didn't freeze!".  I would go plenty low since once it switches over the oil boiler will heat everything up and keep things warm until you build a new fire.

And another observation on the system schematic: when the system is in oil heat mode it looks like there is a parallel path through the Danfoss and/or wood boiler.  Although it is inhibited by the weighted check there might be some unwanted flow nonetheless.  Probably doesn't matter since the oil boiler normally comes on from standby and if you were going to run oil for an extended period of time you could just close the ball valves.


----------



## SIERRADMAX (Dec 8, 2012)

perhaps a motorzied valve can control this placed downstream of the ball valve on the returns side? Controled by a similar snap ring?


----------



## ewdudley (Dec 9, 2012)

SIERRADMAX said:


> perhaps a motorzied valve can control this placed downstream of the ball valve on the returns side? Controled by a similar snap ring?


The weighted check valve is supposed to prevent gravity float but allow pumped flow, but I've never been able to find in the specs what the opening pressure limit is.  

By studying the pump charts for IFC and non-IFC circulators I've concluded it might be on the order of 1 psi.  So if P1 sees a small enough pressure drop through the oil boiler, swing check, elbows, pipe, and tees leading back to the point where the parallel paths join, the the weighted check will not open and everything is fine.  It's reasonable to think so, but you could get fooled without better data to work with.

So maybe just make sure there's a spot where a motorized valve could be added if it comes to that and wait and see.  The worst that can happen is there will be some amount of flow through the wood boiler whenever the oil boiler comes on automatically, then the snap-disc thermostat will shut the oil boiler off and (depending on your control strategy) re-energize P2 until the snap-disc cools down, and so forth kind of stumbling along and more or less heating the house until you get home and shut the valves between the two systems.

Also if P1 is over-sized  it would definitely aggravate the situation.  A Grundfos Alpha or a Wilo Stratos would help a lot in preventing the problem.


----------



## mikefrommaine (Dec 9, 2012)

I'm using a weighted check and it does keep the wood boiler side of the piping cold to the touch when the oil is running.


----------



## SIERRADMAX (Dec 10, 2012)

If I were to add future storage, what should I install & where  so I don't have to rip apart the plumbing later?


----------



## mikefrommaine (Dec 10, 2012)

At the very least a couple of tees and ball valves on the supply and return.

Tarm has a diagram that uses pretty much your proposed design as a starting point but adds in a 3 way valve on the return, another circ and a zone valve in place of the weighted check. You probably won't need the zone valve since you are not zoning with circulators.


----------



## SIERRADMAX (Dec 13, 2012)

If I use a P.A.B., can I install P1 further downstream on the return (closer to the oil boiler below primary loop return), keep P1 from circulating and have P2 serve as circulator to the zones? Will the PAB still function?


----------

