Did I get what I paid for? P/S Piping

Boiled_Over

Thanks for any help in advance. Recently had TT Solo 110/Smart 50 IDHW installed.  I did some research as to what was needed including manual J's (3) and looked at 6-7 contractors. I finally settled on one off TT's web site who said they were factory trained He then proceeded to install straight through piping on 3 zone system when factory spec system was requested. Installer didn't believe new school ideas of primary/secondary or the need for certain check valves, so initially didn't install them. I stopped the check 2 days later and forced them to come back and modify. The attached picture shows the manner he installed the closely space tees when he came back and what it is now. <strong>Does this look right?</strong>  It seems like he just took the easy way out after the factory told him p/s piping was needed.  The tees are 10 inches center to center, bulls oriented towards each other and main supply and returns through the main run of the tee.  It seems like it is still operating like straight through flow with onboard boiler pump and system pump with enough flow to cause a jolt water hammer with one zone opening.  I did not have the fluid dynamic knowledge to stop him again even though I knew it might not be right. If anyone could look and perhaps give me some expert knowledge to make a case for fixing it, I would appreciate it. Specifically the way the main supply and return are piped together.

JohnNY

That depends on what you paid for...

....maybe you just didn't get what you didn't pay for.



Why did you feel like you needed to engage "6-7 contractors" for this project?

Boiled_Over

RE:

The contractors we did not go with had limited to no experience with TT. We paid to simply have the install according to manufacturers installation instructions, nothing more, nothing less. The guys we went with had 17 installs under their belt and stated they were factory trained and were listed on TT web site as recommended contractors. Took them at their word. Any comment on the manner the closely space tees are installed? Flow issues? Thanks for your response.

Ironman

No, That is Not Right

I don't think your installer understands pri/sec or the reason it's required. He did a good job as far as workmanship goes, but it's not correct. Most mod/cons have "high head" (high resistance to flow) heat exchangers and require a separate circulator for the boiler. Trying to use the zone circ. to push through the boiler in series with the system loop, creates too much head for the circ. and produces too little flow through the boiler. The boiler will fail very early and the system won't have enough gpm to give the necessary heat under load. Pri/sec provides a means of transferring heat while maintaining the necessary flow in each circuit. This is called hydraulic separation. A low loss header or a 4 pipe buffer tank does the same.



Flow from one circuit must go straight through the run of both Tee's. They should be placed as close together as possible, not exceeding 12" center to center. The other circuit must come off of the bulls and should flow in and out of them in the same direction (parallel) as the other circuit. There must be a minimum of 8 diameters of straight pipe entering the upstream run; and 4 pipe diameters of straight pipe out of the downstream run. It does not matter if the bulls do not point in the same direction, just that the flow is in the right direction.



I've attached TT's application manual. Notice page 4 particularly. It's similar to your system.

Slimpickins

it's not right but....

No, as Ironman said its not correct.



 I did a service call last year on a Prestige with the problem being a noise like a low hum of a fright train in the distance. It wasn't primary/sec piped and I think it was 8-10 zones of baseboard.  Also, I could tell there wasn't a combustion analysis done. I told him I could do the combustion setup at that time but we'd have to get the lead guy out to do a bid for pri/sec. After setting up the combustion, the noise went away but the customer still wanted it done right after I showed him the installation manual. Meanwhile he calls the factory support and they tell him it doesn't need to be primary/secondary piped on a baseboard system because it only needs 1.7 gpm through the heat exchanger. My superior goes out and told him the same thing making me look like an idiot. I agree there are situations when pri/sec isn't needed but you better be darned sure and do some testing beforehand. I've seen really long zones that have been reduced to 1/2 in places, zones with towel warmers with TRV's inline and so on. It just makes sense to pri/sec pipe it and it doesn't take that much more time. I was upset with the support guy telling that to the customer and my boss should have given him the price to pipe it right because the customer would have done it. Sometimes I hate this business, I'm just out there trying to do the right thing. BTW, I no longer work for that company.

gennady

NO YOU DID NOT GET WHAT YOU PAID FOR.(BUT DEPENDS HOW MUCH YOU PAID)

I hope you did not pick your contractor for lowest bid. But you will have to pay somebody for removal of all this piping and electric. it is not only done wrong, but workmanship is below ground here as well. 

RobG

Gas Piping

Since you are going to need some piping done to the system anyway, the gas piping looks like it may be undersized. Unless the gas meter ,regulator or larger branch piping is within about 8 feet of the boiler the piping is undersized. Where does the piping go on the other side of that wall?  

Did your contractor do a combustion analyses of the boiler when it was started up?  If not that's another thing you need to have done. 

Boiled_Over

RE:

Thanks for the response. There is a one inch gas line coming out of floor right below boiler, so, no problem there. The main issue is, what are the fluid dynamics of the bypass pipe the installer placed between main and return lines as compared to what it should have been with closely spaced tees in instructions on page 22 of the install manual. The installer put that bypass pipe in after I made them come back to plumb according to TT install manual. He obviously did not get it right. My mistake for not holding payment till TT signed off on the changes. I know now what is needed and will try to get them to change it, but, I could use some flow expertise, to make a technical case with them. I am sure it is not like this with many installers, and he is not a bad guy, mostly just had his own ideas of how things should be and unfortunately didn't put much stock in manufacturers installation specs. Most people would not even question it. Triangle tube also agrees it is not right after viewing the pictures, but, they can only lead the horse to water, they can't make him drink. Anyway if there are any fluid dynamic experts out there and can compare the functionality of the bypass line we got to true p/s piping, I would sure appreciate the input.

MrDucks

Pumps & Pipe

Do you have the install manual? Boiler needs a pump for itself & spacing is max 12"  P/S. Plus your dom tank needs it own pump & house zone. Grundfos 3 speed pumps are a good choice. If you look at install manual page 78 etc on manual you will find your presure drops. Check your pipe sizes on boiler & dom tank, Manual says it all, Hope this helps.

MrDucks

Pumps & Pipe

Do you have the install manual? Boiler needs a pump for itself & spacing is max 12"  P/S. Plus your dom tank needs it own pump & house zone. Grundfos 3 speed pumps are a good choice. If you look at install manual page 78 etc on manual you will find your presure drops. Check your pipe sizes on boiler & dom tank, Manual says it all, Hope this helps.

Boiled_Over

Re: McDucks

The Solo 110 has an onboard Grundfos 58 3 speed, the zone pump is a Taco 007 and the DHW pump is also a Taco 007 , 3 pumps in all. Have all the manuals and TT's application guide, I just need some technical reasons why his bypass line between main supply and return is not equal to primary/secondary piping.

clammy

p/s piping / by pass

it is my belief that when using p/s piping there is a hydralic seperation between the flows of the pumps due to piping ,while when using a bypass with more then one pump there is no hydralic seperation and 1 pump can and will effect the flow of another pump.I am not saying your installer is a bad guy except he may need to pick up some of  Dans books to have it explained in a understandable way some time hydronic and hydralic therory and operation prinicals can be a bit hard to grasp but  if explained to in a easy to grasp way completly changes your thought process .Maybe if you get him a copy of  pumping away and p/s made easy you will not have a issue because he will understand the difference and corret your piping ,just a thought .peace and good luck clammy

Ironman

It's not You that has to prove him wrong

Your installer has chosen to pipe your system in a manner that is contrary to the manufacturer's instructions as well as any accepted engineering manual that could be found. You've come come here for expert advice and it's been unanimous that what he's done is not correct. You've more than gone the extra mile to give him the benefit of the doubt. Now it's up to him to prove his method is right and everyone else is wrong. Obviously, he cannot do this as he has nothing but his own subjective thoughts to rely upon. Even if he could show that his method is viable, the manufacturer does not aprove of it and that settles the matter there.



As pointed out already, what he's done is causing hydraulic interference between the circuits. It needs to be re-piped according to TT's specs. That's the sum of the whole matter.



I would recommend that you tell him in a gracious manner that he must re-pipe it according to spec's or that you'll hire someone who will and he'll have to pay to have it corrected. If he needs help, please refer him here or to Dan's book on pri/sec piping. There is a wealth of knowledge available here if he's open-minded and willing to learn and it's our desire to help those in the trade do the best job they can.

bob_46

Forest for the trees

I think you guys are missing the main problem. As far as the 10" piece of 1" copper between the two bulls the only interaction between those two circuits will be the pressure drop in that 10" of pipe. I don't think the water can see the tees. Somebody said what gozinta a T gotta come out. What bothers me about the piping is where the DHW return is

tied in,it should be on the boiler side of theP/S connection after the check. The way it is piped we have three hydraulic circuits tied into the P/S connection. I don't know what the

net effect would be.

Boiled_Over

Re:Bob

Thanks to all for the responses so far. Bob, I agree that the onboard boiler pump and zone pumps are still operating like they are in series as they were before installer came back and attempted to make it p/s. The attached TT diagram is what we thought we would get.

bob_46

Agree?

I don't agree that the on board pump and system pump are in series. I think they areP/S. The third pump for the indirect and where it's return is tied in is what bothers me. Would I have laird out the piping the way it is, no. I think it will work O.K. if you change the DHW return connection.

Slimpickins

manual vs. tech support

Ironman, did you happen to read my earlier post? Just curious to your thoughts on my situation. As Ironman said, they made an attempt to primary/secondary pipe and pump it and it is wrong atnd they should make it right. Good luck!

Ironman

Slim...

I read it and agree with you. 1.7 gal. is only enough flow for minimum fire on that boiler. I don't know where the tech support guy came up with that, but it wasn't from the manual.



 I'm finding more and more of this in our trade: people spouting off what they have imagined is right without knowing the facts. I've also found that a lot of tech support people are barely more than entry level going down a flow chart. Some are very knowledgeable and experienced, but they seem to be the minority now-days. Give me the old days when you called your rep and got the right answer!



Regardless, what's in writing is what stands and what were accountable to do.

Boiled_Over

Light at the end?

Thanks to all the posters that helped me get my head wrapped around what is needed for our system. The contractor agreed to make necessary changes to the plumbing to meet TT's specifications and set up p/s piping. I have attached a rough diagram of what will be the new configuration for closely spaced tees and would appreciate comments or suggestions as compared to the pictures of the existing plumbing.

AlexS

tee's backwards?

From the looks of the sideways diagram, the flow you show for the boiler pump goes against the flow of the system pump, between the two tees.... 

bob_46

Tees

If you want to match the TT factory diagram you need to reverse the two closely spaced tees.

Jean-David Beyer

flow you show for the boiler pump goes against the flow of the system pump

What is wrong with that? My boiler circulator cause water to flow out of the boiler through the two Ts and back down into the boiler. If the flow through the system is more than the flow of the boiler circulator,  hot water will flow through the supply T through the system and back to the return T and back into the boiler. Any excess system flow will go straight through the two Ts.



Only if the system flow is less than the boiler circulator will some water go straight through the supply T to the Return T (against the system flow) and back into the boiler. I do not see this as hurting anything.

Slimpickins

Tee & flow direction

Your drawing looks like the Prestige schematic to me. I've seen the flow from from the boiler (primary) loop going the same direction of the system (secondary) loop and it seemed to work fine. I believe its been talked about on here but can't recall the consensus.

Boiled_Over

Tee & flow direction: New Piping Installed

Thanks for all the helpful comments that were posted. New p/s piping was installed yesterday according to the attached diagram which I cleared with TT Tech Reps and confirmed was in accordance with installation manual. It appears to be working well and the water hammer when a Zone closes seems to have gone away. The one question I have is what speed 1-3 should the onboard Grundfos 58 be set on for proper boiler circuit flow on the Solo 110. My contractor does not know. There is a comparison chart in the manual comparing Solo 110 pressure drop to system head, but, I'm not sure how to apply it. There is only about 6 feet of pipe and a few elbows to and from the close tees. Any help is appreciated.

Ironman

Pump Speed

With a 20* Delta T, you would set it on "high". With a 30* Delta T, set it to "medium". I'd use "medium" and run it closer to a 30* Delta T. This is what you'll get on high fire, under modulation, it will be less Delta T.

RobG

Re-pipe

Can you post some photos of the re-pipe? A pictures worth a thousand words.

Rob