The great piping fiasco? Need help!

[RowCropRenegade]

I've spent the better part of the past week trying to figure out what I have here. I can't do much more in the Garn room until I get this piping rolling. I've built my model out of legos. It's not to scale, and very simplified. I've left out the cold water fill, pressure tank, dhw in my model. It's by no means to scale, but a way to convey what I got to you hearth guys.

The pictures labeled on the model are referenced to the file name of the picture. Please advise me if you can't read the labeling on my model.

What I don't understand about my piping model is why does the downstairs loop T into a return and continues to supply the remainder of the downstairs loop and mix back in at the supply. Picture 8 is where the T is. Picture 2 shows the downstairs finishing its return at supply on boiler out side. It's confusing me bigtime!

Appreciate the help. I'm lost without it.

 

[sgschwend]

Sorry about you plumbing problems, don't really know why it is that way, can you ask the installer?

I did notice that you have dissimilar metals causing a corrosion problem. You need to fix that manual air vent bleed galvanized connection before you have a flood (perhaps this connection is indicative of the other issue, ie another mistake).

 

[sbleiweiss]

Is it possible that this "extra" pipe that runs form the boiler supply and T's into the boiler return was put in as a pressure bypass? Is there a valve in the line to restrict the flow? It could have been added to keep the circulator from being completely blocked off when no call for heat from the zones, or to keep the flow velocity from getting too high and making noise in the pipes? Or maybe an old zone was removed and it is a mistake? How are the zones controlled? Are there zone valves somewhere?

That looks like an electric water heater. If it is piped to the boiler, I sure hope it is piped into a DHW coil in the boiler. There are a number of reasons you can't run DHW straight through the boiler... Most important is that you don't want a steady supply of oxygen into your boiler loop It will corrode everything...

 

[RowCropRenegade]

Thankyou guys for the tips. Sgschwend, I do have corrosion issues, but its not bad for 40 years of operation. All the pipes I inspected in attic and closets are insulated and look clean at joints. I've made a note to change that air out. I'll probably end up redoing it this summer, but I'm trying to understand it better before I go tearing stuff out.

scottb, there is a valve in the boiler room right before it tees back into the main supply side. I can't turn it off because that will shut bot half downstairs off. The return side in my closet needs to be the line shut off. There are no zone valves in this house and the circulator runs 24/7. I also thought my boiler was dumping heated water into my water heater, found manual and said it had tankless coil in the boiler.

I've read 4 Dan Holohan's books and he's always coaxing the reader to think like water. High pressure goes to low pressure. If I'm the water coming to the T in my closet. I have two choices. Go down and across through the floor into 56 more feet of zig zagging radiators or go into a bigger a diameter pipe (less resistance) 12 feet up and go 40 feet back to the boiler. The next room it goes into from my bedroom, is the living room. Which is traditionally colder cause of 2 windows entry door and 12ft ceilings. The thermastat is in this room also.

 

[Jim K in PA]

Reed - all I can say is . . . wow.

I concur with Scott - it looks like your pre-heating your DHW via the coil in the oil furnace, and then sending it to the electric water heater. I would hazard a guess that the electric water heater was added to stop complaints about a lack of hot water.

As to the piping and distribution system, you have a rudimentary one, at best. If the circ is running 24/7 and there are no zone vavles of any kind, the house must get pretty warm in mild weather! What is the t-stat wired to? It sounds like just the boiler control. If there is a Honeywell aquastat, it must be wired for cold start, and is regulating temperature by burner only. What is the hi/lo setting on the boiler?

The simplest thing you can do right now, to get your GARN integrated into the house heat, is to pipe the boiler return main line through a flat plate HX, and counter flow the supply from the GARN through the other side of the flat plate. This will allow everything to continue to function as it is now, and have the oil as backup if the GARN temp drops too low.

Tough to suggest where else to start. Given the season, you sure don't want to tear into the house piping any more than is absolutely necessary.

 

[Hunderliggur]

Are you sure you have the flow correct on the right left hand bb radiator lego? If you mapped this out from actuals it looks like you have a reverse flow in the left hand radiator. Perhaps a check valve in the stub between the left hand and center bb radiator would correct the flow and prevent the cold return in to the hot supply. The check valve would be put in to allow flow from the "top" of the left hand bb radiator towards the T at the "top" of the center bb radiator.

I think your Lego piping diagram is great! And no licens for Microsoft Visio is needed ;-)

 

[RowCropRenegade]

Jim, The t stat is hooked into boiler controls. There isn't any wires going to the pump. Turn up tstat, the boiler fires. Turn on hot water, boiler fires. If there were zone valves in the house somewhere, there would be wires back to pump. My t stat is set at 72 and that makes it around 70 in the house. High limit is at 180 and low 80 right now. I''m the outdoor reset around here. I've screwed with the high low limit for years. I don't fire the boiler in the summer, so the electric hotwater heater does its part then.

I've been trying to emulate your primary loop, Jim. Only difference so far is the primary pump is on return side, so it can be low. I'm doing 2 inch primary with 1.5 return. Top two supplies are house then barn and bot 1.5 return can supply garage/future aps of lower temp water.

Got a 70 heat plate exchanger today. Fair price. Priced the two pumps I was recommended were Taco 0012 Delta T pumps. Sized big enough to handle big barn and house. Not exactly sure how this fits with my current setup yet. Haven't bought them yet. Want to get physical piping in place so a proper measurement can be conducted. The primary loop seems most clear to me right now, so I start there.

TY for the compliments on my legos hunderliggur. Mom and Dad payed for their cost a long time ago, hehe! It backflowing is not what the lego model represents. It's teeing off into a supply and a return. Picture 8/2 show what i mean.

So many questions to resolve. boiler temp low right now cause im running propane fireplace, fooling the thermstat. The pump is a bell and gosset 1/12 hp motor. Rebuilt weird spring assembley/turbine two years ago.

 

[sbleiweiss]

OK, I did not realize that there were radiators on that extra loop. You simply have 2 radiator loops in parallel sharing a return. No problem there.

If I were you I would plumb the HX into the boiler return line. It's the cleanest point that you can tap into this system. The supply side of the boiler is so tight that plumbing the Hx into that point looks like a problem.

With the Garn, you do not want to run that boiler circ 24/7. You will be cooked inside your house. I would recommend adding a circulator relay (TACO SR501) and hook the existing thermostat into the relay control. The relay will run the circulator when the house calls for heat. There are two output relays in the SR501, the second relay will be connected back to the oil boiler control to tell the boiler to fire when there is a call for heat. Since the garn will be heating the loop, the boiler will not fire when the Garn is hot. Just make sure that the boiler high limit is set below the temp that the Garn supplies. The oil boiler might fire initially if there has not been a call for heat in a while, but quickly shut off once the Garn heat starts heating up the oil boiler. It's a compromise for keeping things simple and having just the one circ on the house loop.

I am assuming the circ on the Garn side would run 24/7, but you could also power it in parallel with your house side circulator. Does the Garn side circulator need to be a bronze / stainless pump?

I am dying to hear if you ever need to run the radiant heat in the room with the Garn. My guess is that this room stays plenty warm with no heat other than the boiler...

 

[deerhntr]

J
Priced the two pumps I was recommended were Taco 0012 Delta T pumps. Sized big enough to handle big barn and house. Not exactly sure how this fits with my current setup yet. Haven't bought them yet. Want to get physical piping in place so a proper measurement can be conducted. The primary loop seems most clear to me right now, so I start there.

Reed,

Be real careful with the Delta T pumps. Read my Blog. I have not completely worked my issues out yet, but I am not sure that TACOs delta T pump works well for a system that has such a LARGE OPERATING Temperature range, i.e. the GARN system. I believe the taco delta-t pumps were designed assuming a tight temperature range provided by current fossil fuel boilers, like my oil boiler which operated in a very tight 200F to 180F range. The delta T pumps then allow you to set the supply/return temperature delta, say 20F, and the pump will modulate is speed to match the load and provide that system delta T. But, with fossil fuel boilers, you can always keep your ABSOLUTE temperature in a very tight range. What I found when I installed my delta-t pump with the GARN, is the pump was very happy to operate at a 20F delta-t, when the Absolute temps were say, 140F-120F. The PUMP does not TAKE ABSOLUTE TEMP into account. So even when your heat load is increasing, it WILL not speed up if the TEMP DELTA meets the setting. Big Problem! There are an infinite set of delta-T solutions for a relative temperature delta, when absolute temperature is not taken in to account. I talked with the taco tech support, and I am currently operating my Delta T pump in a set point mode that allows it to run flat out when ever there is a call for heat. The fancy, and expensive Delta-T pump runs like a pump that I could have purchase for 1/3 the price!

 

[Jim K in PA]

Reed, listen to Russ. Get yourself a couple of Grundfos Alpha 3 speed units. I used the UPS43-44 for my primary, and a 26-99 for my house loop. They will have all the adjustment you need. Much later, if you change your house piping/pumping and controls, get a delta P ecm pump for that side of the system.

BTW - you mentioned early in the thread about not showing an expansion tank. Your house-side piping should already have one, yes? The GARN side does not need one.

Double check Dan's book on p/s piping. I'm not sure that putting the loads on the suction side of the pump is a good idea. Can you solve your NPSH demand in some other way?

 

[RowCropRenegade]

It's been an awful day, but still managed to get some grain hauling done. Aside from the grain truck spring a leak in the middle of the night last nite, leaking high priced road diesel all over the floor. Thank our lucky stars we didn't have a fire. Unthank the unlucky stars I decided to fill it yesterday. Then my pickup did some weird stuff.

So time to deal with the problem at home. Brightens my day to see helpful responses.

Scott, I don't believe we are not seeing the same thing. The upstairs loop shares a return with the downstairs, yes. However, it seems odd to put a return in the middle of the downstairs loop and return the remainder of the loop into the supply side. It's almost halfway through the downstairs loop when it returns. Still have 2 big rooms and 3 smaller rooms to do. That's the coldest water in the system. Shouldn't the downstairs finish its' loop and then Tee into the upstairs return? I'm calling it random piping. Dad said there were alot of shoddy (and still is) plumbers in the neighborhood. Stainless would be nice but not necessary. Cast Iron is the norm I think? I don't think I will need the radiant but I will hook it up regardless. It's my learning area.

Russ, you threw a curveball at me. I'm a little relieved, actually. Those 0012 Variable Delta T pumps were 376 a piece, I would need 2. I figured on my primary loop, this would be ideal. I checked out your blog again. I'm now thinking I should try to get a company in here and help me out. This is exactly why I haven't bought the pumps. I figure I'll pipe it out, do the math and size it properly. I've refused to rush it at this point and I'll stay the course. If I have to drive to cincinnati to get the RIGHT pump the last day to fire the unit. I fully understand the complications of your system with the variable delta T pumps. Are they selling faulty pumps?

Jim, the expansion tank pipes out of the top of the output on the boiler. The cold water on its way to the cold water supply on the boiler is Teed into the fill valve and pressure tank. The expansion tank broke 2 weeks ago. It's completely full of water. I've been bleeding water out of it, to relieve some pressure that builds up. It's also in the wrong place according to Gil. The pump does NOT pump away from it. Pumps through the pressure tank. So I get some nasty airlocks if I shut the system off, do any maintenance and hear the water moving, regularly. Also, my pump is creating a negative pressure on its suction side to move the water. Who knows what it's doing right now. I honestly could care less at this point. The boiler is good, the pump is good but the rest looks like scrap copper to me.

 

[deerhntr]

It's been an awful day, but still managed to get some grain hauling done. Aside from the grain truck spring a leak in the middle of the night last nite, leaking high priced road diesel all over the floor. Thank our lucky stars we didn't have a fire. Unthank the unlucky stars I decided to fill it yesterday. Then my pickup did some weird stuff.

I know exactly where you are coming from when it comes to equipment breaking down> I have far to many engines to fiddle with!

Russ, you threw a curveball at me. I'm a little relieved, actually. Those 0012 Variable Delta T pumps were 376 a piece, I would need 2. I figured on my primary loop, this would be ideal. I checked out your blog again. I'm now thinking I should try to get a company in here and help me out. This is exactly why I haven't bought the pumps. I figure I'll pipe it out, do the math and size it properly. I've refused to rush it at this point and I'll stay the course. If I have to drive to cincinnati to get the RIGHT pump the last day to fire the unit. I fully understand the complications of your system with the variable delta T pumps. Are they selling faulty pumps?

I would not say they are selling faulty pumps at all. I just think we have unique situations with our Storage boilers, and they have designed thes pumps for the masses, and let's face it Our GARNs are in the minority. We just need to think a little harder about how are system will work.

Just one thought, you may want to download the Taco HSS program. If you put in a little time, it will help you do the math, and select the right pump. I used, and it work well.

Good luck

 

[sbleiweiss]

If you think about this 3rd return pipe that you call downstairs return as a downstairs supply it seems OK to me. The downstairs has 2 feeds which feed 2 strings of radiators and then come together into a single return pipe. The pump will keep water flowing away from the boiler on this pipe, so it is a supply. That is how it looks in the Leggo drawing to my eye.

Thanks for sharing this install with us. I am quite impressed at how quickly you are able to get relatively huge projects done. This install would take me years...

 

[RowCropRenegade]

scott, I understand what you are saying. Maybe that is what is happening. Maybe I have 3 different loops and them all sharing the same return. I've redone my schematic to reflect that. That makes sooooo much more sense. I'm going to pick up an infrared thermometer today to verify that. Your post this morning has me looking at this project much more positive today.

Happy to share my progress. I have learned so much since joining hearth and through the support of my Garn distributer. I figure it's the least I could do, was give another future wood boiler a roadmap of sorts. This has been the largest project of the year. The time I've spent online, reading, researching and talking to people problably triple the actual working hours. Been worth every minute. Too bad I couldn't get it done before winter. Burning over 10 gal of diesel a day.

Russ, I have that program and found the legos to be faster and more fun. I'll probably do the calculations physically after all the final piping is done. I'm still thinking the Delta T pumps will be ideal for my current system and for future additions. I can live with the cost, it's within budget. I won't fully decide until I know exactly what's going on in this old farmhouse. Your red flags on the pumps has me asking all the right questions...so far.

Thanks! I'm attaching a new schematic to reflect scott's idea. (which i think he is right) If this is the case, I'll take out old pump and put in variable speed zone valve pump with 3 different zone valves. Keep oil boiler warm, heat DHW through oil boiler coil and not have to change much inside. Oil boiler bypass is not indicated but I think I should have one in case oil boiler leaks, cause the whole system to be useless.


Any of you Garn guys put a mixing valve on your garns?

 

[RowCropRenegade]

Also in this picture, I could make a manifold on output side of oil boiler for future radiant loops, DHW etc. (not shown)

 

[RowCropRenegade]

Knew it wasn't a good thing when I showed up to the plumbing store yesterday and the guy leaving had a cart load of black iron material. Managed to get some parts, so I can move beyond legos. I priced a mixing valve for the garn. 2 inch T style with settable mix setpoint. 785.00. Skipping the mix valve, I figure this primary loop will be doing most my mixing for me.

Also confirmed what we were discussing here the other day. Used that infrared temp gauge to verify the flow. 160 boiler temp, 130 pipe temp out of boiler near 115 at the return in closet. I'm guessing the actual water temperaturs is 140-150. Very reason I'm installing temp gauges all over in new systems. What I have is a 3 pipe supply, with single return. Simplifies alot of things.

Anyone have any comments about this potential manifold?

 

[deerhntr]

Knew it wasn't a good thing when I showed up to the plumbing store yesterday and the guy leaving had a cart load of black iron material. Managed to get some parts, so I can move beyond legos. I priced a mixing valve for the garn. 2 inch T style with settable mix setpoint. 785.00. Skipping the mix valve, I figure this primary loop will be doing most my mixing for me.

Also confirmed what we were discussing here the other day. Used that infrared temp gauge to verify the flow. 160 boiler temp, 130 pipe temp out of boiler near 115 at the return in closet. I'm guessing the actual water temperaturs is 140-150. Very reason I'm installing temp gauges all over in new systems. What I have is a 3 pipe supply, with single return. Simplifies alot of things.

Anyone have any comments about this potential manifold?

Reed,
First off that stuff ain't cheap. But Why do you need a 2" mixing valve? I would guess you will want to mix things out closer to your loads, and I can't believe you will need 2" for you load piping. What kind of heat load did you calculate? When I worse case things, it is a stretch to get to 100KBTU/hr, and I have 1-1/4" main distribution, and no more than 3/4" for the zones. I have 10' feet of 1-1/2" black steel from the back of the garn, then all 1-1/4" from there.

 

[RowCropRenegade]

My house/hot water 120k. 85k big barn at least. Plus I have a potential application where it could be possible to demand max garn load, 24 hours a day. Won't specify what that function is. I would be a pioneer if I could pull it off.

I'm sizing this manifold big for just the house. I'll willing to waste some BTUs. This system won't be fully operational for 3 4 5 years. 1.25 will be max secondary line size, but the other top two pairs of Tees might be needed for the barn alone. This is where these delta T pumps makes alot of sense. I agree this stuff is sky high. But at least its not chinese junk. I'll pay the premium for American made. I knew well before I bought this thing that it would be expensive. The primary loop is grossly oversized for now, but future it wont be. Hope this explains my reasoning a little bit.

This manifold will be in the garage, probably the main heater for the room too. It's uninsulated right now.

 

[deerhntr]

My house/hot water 120k. 85k big barn at least. Plus I have a potential application where it could be possible to demand max garn load, 24 hours a day. Won't specify what that function is. I would be a pioneer if I could pull it off.

I'm sizing this manifold big for just the house. I'll willing to waste some BTUs. This system won't be fully operational for 3 4 5 years. 1.25 will be max secondary line size, but the other top two pairs of Tees might be needed for the barn alone. This is where these delta T pumps makes alot of sense. I agree this stuff is sky high. But at least its not chinese junk. I'll pay the premium for American made. I knew well before I bought this thing that it would be expensive. The primary loop is grossly oversized for now, but future it wont be. Hope this explains my reasoning a little bit.

This manifold will be in the garage, probably the main heater for the room too. It's uninsulated right now.

Sounds Like you've got a plan!. Anything above 1" starts to get pricey. I can't wait to see the end result.

 

[Jim K in PA]

Reed - rather than a mixing valve, it might make more sense to pipe an injection loop with a setpoint controlled pump. I know Russ had troubles with his delta T pump, but perhaps the newer ones will address the absolute temp issue?

I have no low temp emitters, so I pipe all the heat I have right through the system. When GARN temps are high, I kind of wish I could mix it down to 170 or so until the temp in the tank drops, but it works so well now, I really have no motivation to work that out.

I think I have an idea what your "mystery" plan might be, but I won't spill the beans . . . ;-)

 

[RowCropRenegade]

Russ, I'm estimating the primary manifold will probably be 1k without the pump. But look at the potential.

Jim, Maybe I'm looking at this mixing valve all wrong. I've decided it won't be a problem until it's all a low temp system OR in 4 or 5 years when I drain the garn, add it then. Garn will be paid for at that point.
I guess I don't understand where the mixing valve goes. Out of back of garn on supply side I thought you put in an inline mixing valve Tee. 2"inch to 1.5" then it Tees into bottom return line. Preset the temp return was what really jacks up the price.

 

[Jim K in PA]

Unless you need the same (reduced) temp water for every load, you don't need or want to mix it at the back of the GARN use the primary S&R. Use a mixing valve on the S&R lines for each secondary load off the primary to set the max temp you want. And only use a MV on those loads that do not require high temp water. For your house with BB emitters, you want the hottest water you can get, so no sense in mixing the primary or the secondary loop for the house. As you add loads with different demands in the future, you can design the supply piping with or without the mixing valve as needed.

In a P/S system, each secondary loop "sees" the primary as it's own heat source, almost like a furnace at each supply point. As you add loads, the temp drops in the primary loop after each load. How much depends on the load, of course. When you plan your layout, you design it so that the load that needs the hottest water gets fed first, and then cascade the loads down from there on the primary.

Hope that made sense.

 

[ewdudley]

Unless you need the same (reduced) temp water for every load, you don't need or want to mix it at the back of the GARN use the primary S&R. Use a mixing valve on the S&R lines for each secondary load off the primary to set the max temp you want. And only use a MV on those loads that do not require high temp water. For your house with BB emitters, you want the hottest water you can get, so no sense in mixing the primary or the secondary loop for the house. As you add loads with different demands in the future, you can design the supply piping with or without the mixing valve as needed.

In a P/S system, each secondary loop "sees" the primary as it's own heat source, almost like a furnace at each supply point. As you add loads, the temp drops in the primary loop after each load. How much depends on the load, of course. When you plan your layout, you design it so that the load that needs the hottest water gets fed first, and then cascade the loads down from there on the primary.

Hope that made sense.

Also I think a case could be made for a 15-20 gallon or so hydraulic-separator/buffer tank in the basement to make the transport loop independent from the load primary loop. This way return temperature to the heating plant could be controlled such that all return water to the heating plant is 'used up' and heat is not pumped back and forth to the load all day.

--ewd

 

[RowCropRenegade]

Jim, I meant a mixing valve for protection of the garn. Keep cool water at end of manifold from re-entering garn below 120. The 3 loops after my house loops could potentionally be radiant loops, you are saying put mixing valves on the secondary S&R of each of those loops. Which doesn't do much for protection of the Garn, or does it?

Apparently, no one has put their primary pump on return side with a Garn. I asked a question that apparently Martin alone has the answer for. Jim did you get your pump moved lower? If so, where did you put it?

If Russ is watching, I'm reviewing how his system is Teed into his boiler room. Looking very similiar to mine, except his future barn loop is my future in house radiant loops.

Every day this project changes a little. Added another Tee to bring in new cold water to the manifold, mount the filter and all. Be nice way to clean out manifold after piping.

 

[deerhntr]

If Russ is watching, I'm reviewing how his system is Teed into his boiler room. Looking very similiar to mine, except his future barn loop is my future in house radiant loops.

Reed.
I'm watching, and the manifold looks good. I originally was going to pipe my GARN with a primary/secondary loop similar to Jim's and similar to your configuration, but when I ran my simulations with the HSS program, the temp drop for my barn caused a bit of concern. I plan to hang a Modine type forced hot air blower, and they really like hot water. So I decided to plumb a supply/return manifold that distributed equal temp water to both loads.

The one question, are your unions dielectric? I could not tell from the picture. I guess if you are all black steel in your GARN boiler room you are o.k. until you change material on your load distribution lines. I switched to copper in my boiler room, so my couplers at that point are dielectric unions.