Is my hydronic system designed incorrectly?

mb123

Hi all. First post. Did a bunch of research and reached out to a few pros. I’m convinced my system is not designed correctly.  

4 zones. Garage on glycol works perfect. Other three not a chance. There are 4 zone circulators and 5 non zone circulators. Which makes no sense. Also Sometimes no hot water for shower. Really stumped.  See video for system as is. Am ready to rip it out and start fresh but would love an engineer to look at it and help me assess.  I’m convinced the bigger piping and other circulators are just whipping the water around and it has no hope of flowing in a loop or where it is demanded. When a zone is on , I feel cold water which makes no sense when the  1 1/2 pipe is hot to the touch. 

 https://youtube.com/shorts/NrQDs-iwH00?feature=share

EBEBRATT-Ed

Either someone is being funny or the wrong video was attached.

Don't bother looking, it's a scam

EdTheHeaterMan

I saw an HTP modcon with a lot of pumps and pipes. If you click on link, and it bounces you to an unrelated video, scroll up to the top video. @mb123 has a real mix and match of systems on one boiler

Here is what I find in the video EDIT after closer look



There is a primary loop from the boiler supply to the return. The red B&G pump moves that loop thru the boiler and that water should get hot enough to heat the water heater (the LAST secondary system indicated by pump H) If you are not getting enough hot water, that pump is most likly not wired to the HTP terminals for DHW priority. Also not the best design for priority DHW but it can work with the right relay.

The Next to LAST Secondary Loop is for the low temperature floor heat using an injection pump to mix the water in the secondary loop to a desired lower temp for Floor Heating. The injection pump should be connected to a variable speed controller in order to add just enough hot water to the secondary loop (using pump D) to circulate the low temperature water so that when one of the low temperature zones can call for heat separately (using either pump E or F or both).

The SECOND from boiler Secondary loop is a high temperature loop that may feed some baseboard radiators (using pump G).

The FIRST Secondary loop feeds a BP Heat eXchanger (using pump B ) and the Garage heat must be the Glycol system that is separated from the rest of the system by the BPHX. Pump C is used to circulate the heated Glycol.

The piping is a sound design for a standard boiler system. Much of the energy saving design of the Mod Con HTP boiler will be lost on this system once the wiring and control logic is figured out. I wonder if this is a job for the Tekmar or Taco system experts on this site. You need a real Brainiac who is control savvy when it comes to this type of complicated system.

This is where i get off this train and let professor Harold Hill get on the train and solve all your TROUBLES with a capital T and that rhymes with E and that stands for Electronics.

EdTheHeaterMan

EBEBRATT-Ed said:

Either someone is being funny or the wrong video was attached.

Don't bother looking, it's a scam

Ed, I think you need to scroll up after the link takes you to the unrelated video. It's a YouTube thing to get you to watch more videos.

I see a Taco Zone control but no injection pump control for the low temperature loops

@mb123, Your query about the piping design... It is not wrong. There are other ways to accomplish this but this should work. #1 I think the garage works so well because it is floor heat and the first loop off the boiler, and the water is actually too hot... so that heats up faster than it should, and it may be robbing all the heat from the rest of the system. I always piped the DHW tank first off the boiler to get priority and the fastest recovery since DHW is not used 24/7. (maybe only 1-1/2 to 2 hours max per day)

GW

Seems kinda normal. You may need a heating guy that understands controls and flow. 

AdamInEvergreen

@EdTheHeaterMan what software did you use to put that flow diagram together?

EBEBRATT-Ed

Well the whole thing is piped wrong.

The low temp radiant shouldn't be the first thing off the boiler (the indirect should be followed by the high temp zones then the radiant.

and all the secondary loops are being fed by different temperatures. It should have been manifolded differently.


That being said it should work the way it is if controlled properly

mb123

Thanks for all the help. This is really useful commentary. Thank you for the schematic layout. That upper zone goes to a  SpacePak setup and the other two zones are floor in basement and floor in room above garage. Zone 4 is not set to priority. If I set the thermostat for the basement up. It doesn’t move and it’s been a week. All the circulation pumps are working and all pumps are variable speed Here is one more video. https://youtu.be/GJ4TAaDAAGs

Rich_49

Where are you located ? Feel free to call me , to at least possibly identify a qualified contractor near you .. I install loads of HTP , this is terrible . Yes , you can use both top and bottom ports , it is actually preferred to use both , one doing space heating and the other for DHW .

mb123

Thanks Rich. Will reach out. I’m in the Chicago area. I’ll send you an email to exchange mobile numbers. 

mb123

One more video. Tonight was a night of no hot water shower  

https://youtu.be/dv3I8UUdIak 

Zman

If you are going to use the infrared, you need to put something non-reflective like electric tape on the pipe first and then shoot at close range so you are only reading the pipe.

What is the boiler setpoint? What temp is the gauge reading? Shooting the pipe at various locations, particularly before and after the double tees is a helpful troubleshooting tool.

Your system pressure looks a bit low, is there a chance you have an air issue?

I don't really like the way your system is designed and piped but I have seen systems like that perform adequately. The key is getting high enough flows on the primary loop so the temp drop from loop to loop is less of an issue.

GW

Right- can’t point at copper and get correct readings. I use a clamp on with copper. 

looks like you have an “injection” setup. Is there a control operating that “jumper
circulator”. If not, that’s kinda weird  

radiant doesn’t take much temp at all when it’s in the slab

GW

Wow that’s is kinda bizarre- you have a main loop, good

you have a “close tee” injecting into a “sub loop”, which is good

Then there’s a second pump on the second loop, with pumps hitting each radiant system. Very odd- seems totally redundant 

the Sub Loop will definitely be “cooler” because of the floor heat 

in general most heating guys never allow the heat and flow to stop in a slab or any radiant situation. Hence the need for a radiant controller like Tekmar 

Seems like there’s a sensor on the “sub loop”, where does that sensor go to? Classic Tekmar situation. 

Whoever piped all that- A for effort 

EdTheHeaterMan

AdamInEvergreen said:

@EdTheHeaterMan what software did you use to put that flow diagram together?

I used Paint S that comes with Mac. Windows has Paintbrush. That is what I learned on for making Illustrations. I only wish I could animate them once in a while.

EdTheHeaterMan

mb123 said:

One more video. Tonight was a night of no hot water shower  

https://youtu.be/dv3I8UUdIak 

Good Questions on your video. The piping is correct, in some cases overdone, but the logic is there In order to know what those two pipes at the bottom of your boiler do, we would need the model number of the boiler. It reminds me of the model ETF but need to be sure. The installation manual would tell you if those capped off connections are for DHW.

To better understand how your system works, you need to read up on some basic concepts used in your system. Basic thing is understanding the Primary/Secondary piping concept. These 2 books can help you available on the Store on this site or Amazon.


Another really basic text it this one. I used it to teach a one day seminar on Hydronic heating.
http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf This booklet was published befroe Primary Secondary piping became popular.

EdTheHeaterMan

I know that you are probably more interested in making it work, and less interested in design and engineering, that goes into how it works, but for a DIY fix, you need to have an understanding of the system.

So far you have confirmed that the primary loop is hot. Probably 170°ish as indicated on the temperature gauge. That is your primary loop and that is where everything else gets its heat from. As long as that is hot then all the other heat emitters can work. Now you have controls that need to distribute that heat to the other emitters like the water heater (DHW) and the radiant floors. This is where a balancing act of adding just the right amount of heat to each emitter zone happens.

Depending on the Electronic Control Logic, the different pumps will put the correct amount of heat into each emitter and stop before the space (or water tank) gets too hot.

So fo example Pump A is already working since the primary loop is Hot. A should be on whenever there is a call from any emitter source. Noe there should be a thermostat on the water heater tank and that wire should be connected to a relay that will operate both the burner and Pump A along with Pump H. Pump H will then stop operating when the tank of cold water is full of hot water.

If one of the radiant floor zones are calling for heat, then the injection pump will add a metered amount of the 170° water from the primary loop and Pump D will circulate that lower temperature water thru the secondary loop (That secondary loop acts like a primary loop for the radiant floor sones at a lower temperature. The Tekmar control should make that temperature happen. Then pump E will take that lower temperature water to the zone and heat that floor. The same can happen with pump F (or bothe E and F at the same time) then the Injection pump Pump D and Pump E (or F) will all stop when there is no call for heat by those zones.

The zone that is troubling me is the garage floor heat zone. There is no evidence of something the will provide a lower floor heat temperature. But that can be accomplished by an injection pump type control the meters the flow the the Braised Plate Heat Exchanger (BPHX) to control the temperature sent to the glycol in the floor heat therein.

This is why you need to find a Hydronics Specialist in your area that understands what is going on there. I had one customer that wanted me to work on this complicated system. He lived in a posh neighborhood and drove a Mercedes, but he did not want to pay for my time to learn his system so i could "Just Install" a heating only thermostat that never was completed by the original contractor. There are about 20 wires in the wall where the thermostat was to be installed and the thermostat had 4 places to connect the wires. I set my son and he called me from the site to tell me this. When I got this information I gave the customer a ballpark $$$ for me to connect the thermostat and he said forget it. A few years later we went thru the same situation again and i did not realise that this call was the same customer and my son called me again and I gave the customer another ballpark $$$ to correct the problem and he again said... forget it.


What I'm trying to say here is that you will need to read up on your system and get to undersatad all the controls , or Pay someone to do that. and it won't be cheeap

mb123

I actually really want to understand it and know it. So I will look into those books. I did read that white paper last night that someone posted in another thread and that helped a lot to understand overall concepts. Funny they are in Morton grove IL which is not far from me.  maybe I should give them a call and see if they have someone local. Here is one more video with blue tape to get better IR readings. 

That garage zone is stealing all the heat it appears so I really have to choose what I want to do. I have three different requests off the main loop before I get to feeding DHW.  

At this point I think I have three options. 

1- leave as is (not realistic)
2- make pointed repairs. E.g thinking of redoing main loop to get DHW priority or pulling it off the bottom of the boiler. 

3- work w hydronic engineer and redo entire system. Right now have one quote for that from someone that was on this board but retired that I reached out to connect. 

https://youtu.be/I-GwhVahYNk 

GW

Garage needs the “least heat” so that should be LAST on the line (primary loop) 

Water heater- doesn’t have to be “first” IF the other pumps shut off while water heater heats up. But——why not make it first, or, have have its pump have its own connection directly to the boiler  

hot_rod

plenty of great hydronic guys in Chicago, Able Distributing, Lyall Thresher Assoc could give you some names.

EdTheHeaterMan

@mb123 If you are still monitoring this conversation. Can you try turning off the Garage Zone to see if the rest of the system will operate properly?

Also is you want to talk to me, Read my Priv Msg. to you

mb123

Still here gang. Just got busy with work. Will update the thread when I can get some time. 

mb123

Hi all. TL:DR = my infloor heating wasn't working, i wasn't getting DHW and a grumpy family taking cold showers. I learned how this work with great help from this site and rolling up my sleeves and learning how it should work. It works now. Read on for more details...


From my last update last winter, out of frustration I just turned everything else off so we can have DHW working and left it alone for the winter, did not use it at all, garage or any of it. Spring and summer came and life continued so did not look at this until last weekend.

So @EdTheHeaterMan you were 100% right, it was a tekmar 361 issue.

Now, how did I figure it out for those that may be searching. When I had guys out here to look at it, they were messing with the tekmar and told me they were disabling the temperature override to make the pump work, which they were not, they were guessing and clueless. IT IS INCREDIBLY HARD to find skilled people that care when they show up at the house.

So fast forward to last weekend and temps dropping again. I decided to print the tekmar 361 mixing manual and read through it very carefully. The first thing I did was remove the electrical trigger wire from the tekmar to the Injection Circ pump and wired that pump directly to make sure the pump works. Confirmed pump was working and my D/E/F on the picture Ed so graciously made, were seeing 125F water. YES.

Now I saw mixing demand on the tekmar control panel but no water flow still. In the manual learned there is a safety check to make sure the boiler has proper temp. So..the final check the tekmar has is "if the boiler has minimum temp, then injection pump gets power". When it has those two (has demand, and boiler temp > min) satisfied, then it calls for mixing based on the criteria that is setup (for me outside temp sensor, plus settings for temp inside etc). Having figured that out, I was feeling good it would work.

Yet...still had no flow! Finally in the instruction for the tekmar, it states the internal temperature is a guess on their part and not a real measurement, and since I don't have an internal thermostat wired to the tekmar, it couldn't know. So I followed the instructions and adjusted the desired temperatures in 10 degree increments and let the mixer save the settings to see what it wanted for mix and targets. I finally landed on arbitrary numbers of 85 degrees internal occupied. Now the tekmar can do it's job and take that, plus the settings, plus outside temp to figure out the mix of water it should start moving. Once all that was done, tekmar demanded a target of 104 degrees and water started flowing and I started seeing the temp go up. Two days later, the floor now is a cozy 75 degrees and I have no interruption to DHW!

Thank you all for the help and comments in here, I truly appreciate it and the family is no longer grumpy

EdTheHeaterMan

Did I draw That?

Damnit I'm good!

Glad I was a small part of your solution. Thanks for the feedback

mb123

Yes Yes you are that good, thanks again!

mb123

hello again, it's been a year I finally found a guy that understands hydronics and had him look at the system. I told him all the trials and tribulations and issues with hot water in the house. He cleaned the boiler and maintained it and then noticed it had been constantly cycling (none of the other guys seem to catch that and candidly I didn't know it wasn't suppose to). He concluded that the old boiler before the HTP was probably a floor standing Weil of some size that was replaced and the HTP was not programmed properly to run the return pump while there was DHW demand. and so we looked it up in the manual and there is that setting exactly!

What seemed to be happening is i was circulating off the main loop and the water was not going back to the boiler because the return pump was not programmed to turn on with DHW.

So finally, there is hot water all the time. no upset family and it was a programming issue. I have learned a ton on this forum and will continue to keep reading and learning. My next stage is fine tuning the tekmar 361 and getting that dialed in. thanks again!