Adjusting TT Prestige Solo 110 CH Operation

JustinS

If you look at the underside of the boiler in this pic, when we get rid of the loopback between CH-Supply and DHW-Supply, in what way would be best to interconnect the CH-Supply and Return ports?

Would you eliminate the loop at the orange arrows and then maybe tie the CH-Supply and Return with piping along the yellow arrows?

Zman

That is ugly and still not really right. Here is a drawing of what primary/ secondary should look like (credit to Mark Eatherton).
If it were mine, I would eliminate the boiler circ and pipe it direct.
Either way, do it right. It really will not take that much longer.
Carl

JustinS

I'm sorry but I'm confused by what you mean by "pipe it direct"?

The drawing you posted - that shows P/S in series, right? Where is the boiler in it?

When TT shows the boiler in Figure 9 of the installation manual, it's secondary, right? Figures 11/12 show it as primary, right?

I'm struggling to apply the TT drawings and figure out how to connect the CH-Supply and Return, particularly because of the arrangement of the piping... as I look at the TT drawings, it seems that the T to the Return should be after/below the right-most orange arrow but I am unsure about that... and then the loop between the CH-Supply and Return should be after that?

it's unclear as to how the two should tie together, especially because the DHW return piping is upstream of where the zone returns tie into the return header...

wrxz24

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Paul48

Follow TT's directions, period.

JustinS

wrxz24 said:

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Are you sure? TT didn't mention anything like this when they were here and the diagrams don't seem to show a bypass valve when using zone circulators? Wouldn't the bypass valve only be required to allow flow when the zone valves are all closed? Wouldn't flow be able to go through one or more of my circulators IF needed to relieve DP?

Though, maybe what I have is closer to Figure 11 since my boiler is inline with the system piping - I just don't have the zone valves so I dismissed it...

JustinS

Paul48 said:

Follow TT's directions, period.

This is a little difficult since I'm getting conflicting directions between TT's service guy, tech support and the manual...

Service guy said to tie CH-Supply and Return together in a loop near boiler, tech support said to put the loop on the far side past the zone circulators and the manual doesn't really have my setup (although, maybe Figure 11 is closer than Figure 9 since my boiler inline with the system loop)...

wrxz24

JustinS said:

wrxz24 said:

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Are you sure? TT didn't mention anything like this when they were here and the diagrams don't seem to show a bypass valve when using zone circulators? Wouldn't the bypass valve only be required to allow flow when the zone valves are all closed? Wouldn't flow be able to go through one or more of my circulators IF needed to relieve DP?

Though, maybe what I have is closer to Figure 11 since my boiler is inline with the system piping - I just don't have the zone valves so I dismissed it...

Not sure, I am on relaying info that was given to me. I was in the same boat as you, piping was the same but diagram had zone valves instead of circs.
I just went with what I felt was the safest route. The boiler gets the correct amount of flow no matter what the other zones are doing. If you have any mechanical skills at all and can sweat pipe, you can make the changes yourself.
I would do like I did and figure out a way to connect the two headers together and make a nice spot for the closely spaced t's and pipe back to the boiler. Put a check valve on the return.
Dhw supply is off its own tapping and return ties into the return from the ch. Put check valve on return from indirect too.

Paul48

I don't think there is anything more we can do for you Justin(from this side of the screen). We've pointed you at all the tools you need to learn. You've had the TT rep at your house. You needed to have a clear understanding of what he wanted done, before he left your house. Guys tried to tell you to just get another competent installer to fix the thing, and you chose this route. You have to figure it out, now.

JustinS

wrxz24 said:

JustinS said:

wrxz24 said:

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Are you sure? TT didn't mention anything like this when they were here and the diagrams don't seem to show a bypass valve when using zone circulators? Wouldn't the bypass valve only be required to allow flow when the zone valves are all closed? Wouldn't flow be able to go through one or more of my circulators IF needed to relieve DP?

Though, maybe what I have is closer to Figure 11 since my boiler is inline with the system piping - I just don't have the zone valves so I dismissed it...

Not sure, I am on relaying info that was given to me. I was in the same boat as you, piping was the same but diagram had zone valves instead of circs.
I just went with what I felt was the safest route. The boiler gets the correct amount of flow no matter what the other zones are doing. If you have any mechanical skills at all and can sweat pipe, you can make the changes yourself.
I would do like I did and figure out a way to connect the two headers together and make a nice spot for the closely spaced t's and pipe back to the boiler. Put a check valve on the return.
Dhw supply is off its own tapping and return ties into the return from the ch. Put check valve on return from indirect too.

My DHW pump has an IFC - would I still need a check valve in the DHW return before it merges with the CH returns?

Any suggestions on where I might tie the headers together? It seems like it should be to the right of the boiler (since that's where all the piping is) but the zone controller and e-switch are to the immediate right so that's probably out... then I thought, well, maybe further to the right with all that empty space in the corner but that's after the expansion tank and I believe that the tank needs to be after the closely-spaced Ts, right?

JustinS

Paul48 said:

I don't think there is anything more we can do for you Justin(from this side of the screen). We've pointed you at all the tools you need to learn. You've had the TT rep at your house. You needed to have a clear understanding of what he wanted done, before he left your house. Guys tried to tell you to just get another competent installer to fix the thing, and you chose this route. You have to figure it out, now.

I thought that I had a clear understanding of what he wanted which was to tie the CH-Supply and Return together under the boiler... he didn't think that the closely-spaced Ts were needed... but Carl commented that he thought this approach was ugly and still not really right...

Similarly, when I asked him about the check valves on the return lines (like wrxz24 recommended), he advised against them as he's seen them fail...

Maybe I should just stop all of this and just get another installer; it'll cost $$$ but it's probably the only way I can get this done right... before the TT rep left, he gave me the name of an installer that he likes - maybe he was trying to tell me something... in fact, the original installer messaged me today saying that he'll cut a ball valve in that loop under the boiler and it seems like he thinks that's all that's needed... Carl would probably think that's HIDEOUS ;-) :-)

Zman

Yes, hideous comes to mind.
My point is, either do primary/secondary correctly using the clearances shown in the drawing I posted or pipe it direct eliminating the circulator in the cabinet. I don't like the idea of a redo that is butchery. That is what you have now.
I have said from the beginning that I think you are wasting you time trying to convince the original installer who does not get it (and never will) that they should fix something that don't (and never will) think is wrong.
Personally I think you are wasting your time fighting an unwinnable battle. Sometimes we all make mistakes that cost us money. You can't win them all.
Carl

Paul48

Justin....Bite the bullet and contact the recommended installer. You've got to get this resolved. We can answer questions in 100's of more posts, but that's not gonna " get 'er done".

JustinS

Paul48 said:

Justin....Bite the bullet and contact the recommended installer. You've got to get this resolved. We can answer questions in 100's of more posts, but that's not gonna " get 'er done".

I contacted the recommended installer earlier this afternoon - hopefully, they'll get back to me soon...

I'll be sure to let you all know how it ends up looking... thanks again for all your help (and patience ;-) :-) )...

wrxz24

JustinS said:

wrxz24 said:

JustinS said:

wrxz24 said:

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Are you sure? TT didn't mention anything like this when they were here and the diagrams don't seem to show a bypass valve when using zone circulators? Wouldn't the bypass valve only be required to allow flow when the zone valves are all closed? Wouldn't flow be able to go through one or more of my circulators IF needed to relieve DP?

Though, maybe what I have is closer to Figure 11 since my boiler is inline with the system piping - I just don't have the zone valves so I dismissed it...

Not sure, I am on relaying info that was given to me. I was in the same boat as you, piping was the same but diagram had zone valves instead of circs.
I just went with what I felt was the safest route. The boiler gets the correct amount of flow no matter what the other zones are doing. If you have any mechanical skills at all and can sweat pipe, you can make the changes yourself.
I would do like I did and figure out a way to connect the two headers together and make a nice spot for the closely spaced t's and pipe back to the boiler. Put a check valve on the return.
Dhw supply is off its own tapping and return ties into the return from the ch. Put check valve on return from indirect too.

My DHW pump has an IFC - would I still need a check valve in the DHW return before it merges with the CH returns?

Any suggestions on where I might tie the headers together? It seems like it should be to the right of the boiler (since that's where all the piping is) but the zone controller and e-switch are to the immediate right so that's probably out... then I thought, well, maybe further to the right with all that empty space in the corner but that's after the expansion tank and I believe that the tank needs to be after the closely-spaced Ts, right?

You need check valves on both. You particularly do not want ghost flow from ch getting into your indirect piping.

As far as where to connect the manifolds, you do have room to the right of the boiler, you could extend the manifold piping and turn the corner and head back toward the boiler. you could move your expansion tank as well making sure you have a good deal of straight pipe before and after the T's. There is a rule to this, not sure what it is off the top of my head. My t's are before my expansion tank with the supply from the boiler closer to the expansion tank than the return T. Make sure you have a check valve on return piping as you do not want ghost flow into your ch circuit during a dhw call.

JustinS

wrxz24 said:

JustinS said:

wrxz24 said:

JustinS said:

wrxz24 said:

I believe yours is piped direct but you have to eliminate the in cabinet pump but I remember when I was discussing this with the experts, you will need a differential pressure bypass valve between your supply and return piping.

Are you sure? TT didn't mention anything like this when they were here and the diagrams don't seem to show a bypass valve when using zone circulators? Wouldn't the bypass valve only be required to allow flow when the zone valves are all closed? Wouldn't flow be able to go through one or more of my circulators IF needed to relieve DP?

Though, maybe what I have is closer to Figure 11 since my boiler is inline with the system piping - I just don't have the zone valves so I dismissed it...

Not sure, I am on relaying info that was given to me. I was in the same boat as you, piping was the same but diagram had zone valves instead of circs.
I just went with what I felt was the safest route. The boiler gets the correct amount of flow no matter what the other zones are doing. If you have any mechanical skills at all and can sweat pipe, you can make the changes yourself.
I would do like I did and figure out a way to connect the two headers together and make a nice spot for the closely spaced t's and pipe back to the boiler. Put a check valve on the return.
Dhw supply is off its own tapping and return ties into the return from the ch. Put check valve on return from indirect too.

My DHW pump has an IFC - would I still need a check valve in the DHW return before it merges with the CH returns?

Any suggestions on where I might tie the headers together? It seems like it should be to the right of the boiler (since that's where all the piping is) but the zone controller and e-switch are to the immediate right so that's probably out... then I thought, well, maybe further to the right with all that empty space in the corner but that's after the expansion tank and I believe that the tank needs to be after the closely-spaced Ts, right?

You need check valves on both. You particularly do not want ghost flow from ch getting into your indirect piping.

As far as where to connect the manifolds, you do have room to the right of the boiler, you could extend the manifold piping and turn the corner and head back toward the boiler. you could move your expansion tank as well making sure you have a good deal of straight pipe before and after the T's. There is a rule to this, not sure what it is off the top of my head. My t's are before my expansion tank with the supply from the boiler closer to the expansion tank than the return T. Make sure you have a check valve on return piping as you do not want ghost flow into your ch circuit during a dhw call.

Thank you

JustinS

Something else I was wondering (sorry if this has already been explained)...

With P/S piping, any flow that is unused by the secondary loops would "go to the right" towards the return T and join up with the flow that was used by the secondary loops before going up the T into the Return...

I understand how I'd now have constant flow through the boiler but wouldn't I still have the potential to short-cycle because the unused heated water goes back into the boiler? Or does the fact that it's entering the boiler the way it's supposed make all the difference?

Just curious...

Gordy

P/s

Paul48

http://www.comfort-calc.net/primary-secondary_piping_tutorial.html

wrxz24

JustinS said:

Something else I was wondering (sorry if this has already been explained)...

With P/S piping, any flow that is unused by the secondary loops would "go to the right" towards the return T and join up with the flow that was used by the secondary loops before going up the T into the Return...

I understand how I'd now have constant flow through the boiler but wouldn't I still have the potential to short-cycle because the unused heated water goes back into the boiler? Or does the fact that it's entering the boiler the way it's supposed make all the difference?

Just curious...

I believe you could still short cycle depending on the size of your zones. What I did was combine all 3 of the in floor radiant zones, my main floor zone with my bedroom and garage zone with just 1 tstat.
You will now be dealing with 2 delta t's between your secondary loop and now the boiler loop. I do not pay too much attention to the boiler loop delta t. Although I usually have a 10-20 on my boiler loop depending on the outside temp and if my upstairs baseboard zone is calling.

JustinS

Something else I was wondering (sorry if this has already been explained)...

With P/S piping, any flow that is unused by the secondary loops would "go to the right" towards the return T and join up with the flow that was used by the secondary loops before going up the T into the Return...

I understand how I'd now have constant flow through the boiler but wouldn't I still have the potential to short-cycle because the unused heated water goes back into the boiler?

wrxz24 said:

JustinS said:

Something else I was wondering (sorry if this has already been explained)...

With P/S piping, any flow that is unused by the secondary loops would "go to the right" towards the return T and join up with the flow that was used by the secondary loops before going up the T into the Return...

I understand how I'd now have constant flow through the boiler but wouldn't I still have the potential to short-cycle because the unused heated water goes back into the boiler? Or does the fact that it's entering the boiler the way it's supposed make all the difference?

Just curious...

I believe you could still short cycle depending on the size of your zones. What I did was combine all 3 of the in floor radiant zones, my main floor zone with my bedroom and garage zone with just 1 tstat.
You will now be dealing with 2 delta t's between your secondary loop and now the boiler loop. I do not pay too much attention to the boiler loop delta t. Although I usually have a 10-20 on my boiler loop depending on the outside temp and if my upstairs baseboard zone is calling.

That's exactly what I was wondering... I assume that it could happen if the zone's BTU requirements are less than the minimum output of the boiler... in that case, I would want to consider a buffer tank, right?

I've got the new HVAC company coming by this afternoon - wish me luck!

P.S.

I'm sure I'll get a lot of "I told you so" but I followed up with the original installer yesterday after the supply house got back to him... what a mistake that was!

He continued to blame TT for the loopback, saying that it used to be required in order to ensure adequate flow through the HX during post-purge or something like that... he repeated that the piping design is what they showed him ten years when this was supposedly the case (as if two outlet ports with separated functions would ever be joined together!!!) and it's their fault because they changed their design so the HX is smaller now or something like that... as my wife said, "even if that is true, what you're not supposed to stay up to date and follow current instructions?!?!?"

He was also not pleased that I went over his head - poor little feller ;-) :-)... claiming that both TT and the supply house were frustrated with me for working to get this all squared away... truly amazing the BS to come out of this man's mouth...

I'll say this, it took a LONG time for me to truly realize what a fool and a jerk he is but it's finally come to pass... I think I'm going to enjoy writing the negative review on Angie's List and maybe BBB...

JustinS

Wondering something - I have the following radiation on my three zones for my 2200 sq ft home...

• 1st floor - ~39 ft plus kickspace heater
  
• Master BD - ~25 ft for ~45% of upstairs
  
• 2nd floor balance - ~25ft for ~55% of upstairs
  

Since two of my zones individually are a smaller load than my boiler's minimum output (1st Floor's pretty close to it), should I consider putting in a buffer tank? Seems like I'd probably continue to short-cycle after re-piping...

From what I've read, they provide hydraulic separation so it seems like I wouldn't need to re-pipe P/S (I'd clearly have to fix my loop between CH and DHW supplies still)...

Thoughts? Worth exploring?