Propane boiler & high temp baseboards, install issues - where to start?

AdamInEvergreen

Hey all,

I have a Trinity Ti-150 condensing boiler. I've lived in the house for four years and would like to make some improvements to the system. Current it does a fine job of heating the house, perhaps a little slow, maybe 90-120 minutes to heat the entire house when recovering from a setback. It seems like it could be more efficient ($3k for propane last year, minimal setbacks because we were here all the time, thermostats set at 60-62F). Also the system is very noisy. There is expansion noise (mild clicking and loud snapping) when a loop starts and big water hammer on half the loops when shutting off.

I noticed that the outdoor reset was not hooked up which makes the boiler operate in "standard mode" meaning it goes all out until it gets to the set temperature (currently 190F). I can't find an efficiency curve for this particular boiler but I assume it something like this:


But that is for natural gas and probably low elevation. I'm on propane at 8,500 feet, which I think means it would be lower, perhaps 120F (educated guess, can't find any good info on it) instead of 135F for that "Dew Point." With this boiler I can change how aggressive the rest curve is and set the max output temp. Default curve has a revised max output temp of 141F when it is 40F outdoors, and at 0F outdoors it will use the boiler max temp. I can post a table if that helps. Anyways - are these lower temps even worth chasing? I think I'd have to give up doing setbacks...and maybe change out a bunch of radiators. I'll probably just give a try and see how it performs.

Install issues; there are two Grundfos UPS 26-99FC 1/6HP pumps, one pumping away from the boiler towards an expansion tank (I hear this is a no no as it causes air issues) and the zone valves. The other one pumps towards the boiler. There is a "closely spaced tee" set with a valve in the middle but it is right off the boiler, which doesn't match any diagram I've seen. No instructions were provided with the system so maybe that valve on the Tees was supposed to be closed anyways. I haven't looked in to pump sizing yet so I have no idea if those are over sized or what setting (hi med low) I should be using. So one thought here is get one or more fancy new variable speed pumps and relocate them so the expansion tank is before.

Lastly one of my loops might be too long...76.5 LF of radiators. Using the cheapest one I see on SupplyHouse (which matches visually) that is 600 BTU/ft at 180F, or about 46k BTU total. Grand total for all 5 loops is 181LF or 109k BTU.

Sorry this is very long and complicated. Like I said - I'm not sure where to start!

Hot_water_fan

Can you post how many gallons of propane (by fill up dates) you've used combined with your zip code or nearest town? That'll get us to your real heat loss.
The short answer is yes, lower temps will save you propane. By knowing your heat loss (you've supplied the amount of radiation) we can figure out the water temp you'll need at design temp.

AdamInEvergreen

@Hot_water_fan So I've got some data form 2017 and 2018, then it gets a little confusing because I went from a 500 gallon to a 1,000 gallon tank and then my record keeping stopped shortly after. My current provider has data back to 2/22/20 so I'd just assume start there. Looking back at the prior years it actually looks like our usage was similar.



I have a Jotul gas free standing fireplace which is probably on 1-2 hours /day average during the heating season. There is also a gas range and BBQ which makes up some tiny amount of that.

Edit: Town is Evergreen, Colorado. Zip code is 80439, but I'd use the town.

Hot_water_fan

Looks good! You'll be able to condense the vast majority of the year. If you're comfortable at those set points, the baseboards will actually have higher outputs compared to their ratings (they're rated at 65 entering degree air).

Using Centennial Airport's weather data, from 2/26/20 to 6/28/2021, there were 4805 Heating degree days (using 55 base temp since you keep the house at 60). You used 2,300 gallons * 90% efficiency * 91,500 Btu/Gallon = 189MMBtu needed, so that's 39kBtu/HDD. That puts you at about 57,000 Btu/hr at 20 degrees outside. 140 degree average temperature water can output 320Btu/ft, so that's about 58k Btu (even more if you adjust up for the lower entering air temperature). That puts you right at the condensing temperature, and 90% of your heating season will have a lower heat loss than that. Replacing some with higher output baseboard will get you even more condensing, but that comes at a cost. Easiest method would be to experiment some with smaller setbacks and lower temps and report back.

HomerJSmith

A couple of questions. Perhaps you should post some pics of your sys.

Why such large pumps and two you say? Yes, always pump away from a Ex tank. You have zone valves, I would have used a ECM pump, pumping into zone valves. You may have a primary-secondary piping sys with closely spaced tees? One pump on the secondary boiler piping and one on the primary heat distribution piping. I would question the pump sizing. Too high a velocity can cause erosion and pipe failure. You have 3/4" copper supply piping to your heat emitters?

Out Door Reset sensor is essential for economy and setting the reset curve. At your altitude a combustion analysis of the boiler is mandatory, and I assume you did an LP conversion on the gas valve?

AdamInEvergreen

@Hot_water_fan Reporting back after approximately one month of heating season and it is running great at the lower temps. Before some of my zones were short cycling, especially the room where I sleep, and with my water hammer issues it was super annoying. Now the zone is running a bit longer and expansion noise is milder. Propane usage appears to be about half, but my historical data isn't great for early season usage. On top of that my thermostat settings have changed a lot since last year. Too many variables at once to know how much savings it is generating.

First day I ran it I noticed there was a lot more condensate coming out of the drain. As soon as I saw it I thought "well, that makes sense given it is spending more time in the condensing zone." I put in a condensate neutralizer because there wasn't one there.

@HomerJSmith I really apologize! I missed your post somehow.
It is hard to show in pictures because it was sort of built in a U shape. Heres a video, pictures below.
https://photos.app.goo.gl/nTHqBDDPuAJ16ah3A

There are "closely spaced tees" but I am not sure if they are optimized. They aren't that close (7" center to center, 1" diameter pipe) and there is a ball valve in the middle. It also doesn't quite fit the diagrams I've seen for primary and secondary systems, but I could be wrong.

Everything is 3/4" from the zone valves all the way back to the return header.

Pumps are on the medium setting. I could do low? It was high when I moved in a some old school boiler guy said "seems to fast" but other than that tidbit I haven't looked in to what it should be.

I assume a combustion analysis was done because the original installer is a local company that put their sticker on there. That's a reasonably bold assumption I suppose.

NEW PROBLEM: That PEX line installed was installed a couple years ago during a remodel is not oxygen barrier. So I'm thinking maybe some chemical in the system once a year. Sentinel x100?


PS: I have the cover off because you can't see the status window (right side, against the wall...) or the flame window with it on. NTI...

Zman

The foil tape on the vent is a sign that a combustion test was done at some point. It should be repeated, especially on propane systems.
The "closely spaced Tees" are not installed correctly or functioning as they should.
The zone circ is oversized and pumping towards the expansion tank. It is also mounted with the shaft vertical which is not correct and will shorten its life. That washing machine hammer arrester on the purge valve tells its own story.
The boiler circ is probably sized correctly but should be pumping into the boiler and away from the tank.

I would suggest installing a true hydraulic separator and moving the expansion tank to that point. You could then flip the circs so they "pump away" from that point. A Delta P circ like the Grundfos alpha would be a nice replacement for the zone circ.
https://www.supplyhouse.com/Caleffi-548097A-1-1-4-Sweat-Union-Hydronic-Separator

Rich_49

Let's get that upper circ motor out of the vertical position also . Those closely spaced tees are also in an inadequate orientation . Needs to be changed .

AdamInEvergreen

@Zman thanks for the info! A few questions...
1) Is 1" (about 11GPM) good or is 1 1/4 (about 18 gpm) necessary? Most of the main stuff around the boiler is 1", except there is a hand made header around zone valves and return that gets up to 1 1/4".
2) I don't see anything in the specs about x lengths of straight pipe. Can I do a 90 right off of the hydraulic separator?
3) Is any amount of space required before the pump? Can I get the appropriate flange and attach the pump(s) right to it? I've never seen that in an install picture but I'm trying to imagine how this is going to physically fit in my system.
4) Is the Resideo (Honeywell acquisition) brand decent? Their hydraulic separators are substantially cheaper than the competition and with their adapters it seems like it would be easy to rig up with a pump, and it has a clever magnetic thing to capture ferrous debris.

The fuel cost (propane) is notably higher per BTU for an efficiently operating system when compared with mini splits...between that and all the maintenance issues described here I'm really thinking about just taking a sawzall to this thing (dramatic, obviously, but you get the idea). I think if I could get 1-3 years more out of this system that would be great. DIY where I can, screw type fittings over sweat (easier to resell), not spend a million $$$. You get it.

Edit: FYI SupplyHouse search is kind of broken when it comes to searching for hydraulic separators. They have a lot more than come up. D&B, Resideo, Spirovent, Taco, Caleffi.

Zman

1. You can probably get by with 1", 1 1/4" would be ideal.
   
2. The manufacture will have recommendations on the straight pipe requirements. For the circ, 5X diameter is ideal, this is often difficult to obtain.
   
3. The biggest issue with your circ install is the vertical shaft.
   
4. Caleffi has a proven product (and @hot_rod needs the money for the new shop ), I have never seen the Resideo
   
   

HomerJSmith

Wow! I looked at your photos and video. I'm aghast, so many mistakes. Many which have already been noted. I always know when reviewing a sys which was done by a hydronic specialist and one done by a plumber or homeowner. It appears yours was done by a plumber, but that doesn't help matters.

1. Your dang pumps are too big, high velocity water creates noisy pipes and pipe erosion. When using a fixed speed pump on a zone valve sys velocity problems ocurr, one need a ECM pump or differential pressure valve to adjust the flow when only one zone valve is open.

2. We don't do closely spaced tees thatta way. In a primary/secondary sys, it's done on the same pipe. Your setup doesn't separate the boiler flow from the heating flow, I think. Zman's right.

3. Placement of the expansion tank is important. You probably could have used an Extol 30 instead of an Extrol 60, saving money. Your pressure on the bladder should be set at 15 psi (my preference).

4. Your pressure/temp gauge (tridicator) appears to be on the inlet to the boiler rather than in outlet from the boiler.

5. Out door reset? Get one after the boiler is correctly installed.

If the boiler is good, use it, and repipe the sys as a true primary/secondary sys. I would suspect that the flow in the boiler is 14-15 gal/min. Use the pump size that NTI recommends for the boiler pump. Get the installation instructions and follow them. Get an ECM pump for the heating sys and pump into the zone valves and away from the Xtank.

Resideo hydro sep are ok. follow the flow rates thru them in determining the size. The only concern that I have is that they use rubber seals at all four inlets/outlets. I prefer the fibre washers that Caleffi uses. One could ditch the rubber and use the fibre washers.

AND...that boiler need cleaning per 3 year intervals.

AdamInEvergreen

About pump sizing...the pumps I have on there now have a hi-med-low setting. When I moved in it was on high...for the last few years I've had it on medium. Set it to low last night to see what would happen. Seems all right, but manual is pretty gloom and doom about inadequate flow rates so maybe I should put it back?

Slightly interesting about the manuals...the first revision of the manual (7/20/2010) calls for a Gundfos 26-99, which is what I have (two of them). The most recent version (10/13/2015) calls for a 15-58 with the note it needs to be bigger if you have a DHW circulator.


(I have the 150 model)

Current manual link:
https://ntiboilers.com/wp-content/uploads/2018/12/Trinity-Ti-IO-Manual-2015-10.pdf See page 34.


I'm still trying to figure out how to install the hydraulic separator in a way that makes sense...seems like I may need to rebuild the return manifold.

hot_rod

But at the end of the day the home, the structure dictates the amount of fuel used. Check any insulation or air leakage you can still see.

The lower the boiler temperature, the higher the efficiency. As long as it keeps you comfortable.
Certainly some improvements could be made in the piping, it may not make a huge difference in fuel consumption.

Efficiency of the building, efficiency of the fuel to hot water, then distribution efficiency.

Tom_133

adaminevergreen said:
Edit: FYI SupplyHouse search is kind of broken when it comes to searching for hydraulic separators. They have a lot more than come up. D&B, Resideo, Spirovent, Taco, Caleffi.

Hey Adam,
I have found the best way to do this is click on the tab heating, then air elimination, then on the left click on hydraulic separators

Erin Holohan Haskell

I've shared this feedback about site search with SupplyHouse.com. Thanks!

Zman

The 15-58 on high or the 26-99 on low are reasonable selections for the boiler side.
A 15-58 or Grundfos Alpha would likely be a better choice for the system side. For now, set both to low and make sure to keep the system pressure up so the vertical one won't lock up.

Zman

Erin Holohan Haskell said:

I've shared this feedback about site search with SupplyHouse.com. Thanks!

Their search feature is getting better all the time. Sometimes you need to find one product and then go back to the subcategory to find the rest. They have a huge inventory, they must have a small army keeping track of it all.

Tom_133

Zman said:

Erin Holohan Haskell said:

I've shared this feedback about site search with SupplyHouse.com. Thanks!

Their search feature is getting better all the time. Sometimes you need to find one product and then go back to the subcategory to find the rest. They have a huge inventory, they must have a small army keeping track of it all.

Then its usually a day away with free shipping! I love that site, very few mistakes as well.

AdamInEvergreen

Ok folks - I've had a few vendors out to try to quote fixing this thing up. One guy said he wasn't interested in rebuilding the piping and would only quote a new boiler (still waiting on the actual quote). Just got another quote in for xxx (edit: I see it is against to rules to publish pricing...I'll just say it was very high). New boiler quoted is perhaps over sized (199k BTU vs the current 139k), perhaps due to including DHW and needing to cover a big temperature increase. Major factor in the rebuild price being high is he doesn't want to re-use any equipment, which I can respect. So I'm back on the DIY track...I'm thinking of tackling it in phases to make sure I don't get in too deep.

Right away:
-Inject Fernox F1 Corrosion inhibitor as a band aid for the non-oxygen barrier pex

Phase A)
-Rotate vertical shaft pump. I think this will be relatively easy. Remove current flanges with a torch and either re-solder them 90 degrees or press new ones on.
-Unscrew current boiler drain on the output and put in a pressure gauge. Install a temp & pressure gauge on boiler inlet as I'm curious about inlet temps.
-Buy a new air separator, boiler feed, new Alpha2 delta-p. Use NPT so I can adjust with later phases. 1" or 1 1/4" for $150 more? Main piping is all 1". Pull out current zone pump and put in copper pipe.
Note: Should solve air problems, wont fix hydraulic separation. Am I going to make hydraulic separation issues worse by moving the zone pump on the other side of my current closely spaced tees?

Phase B ) (maybe after this heating season)
-New return manifold with nice t-flow valves for easier draining
-Create closely spaced tees between new return manifold and the phase A section, remove old "kind of" closely spaced tee setup. Or install a hydraulic separator, but it seems really challenging to install in a clean way. If I could put cold/return on the top ports and/or install the make up water/expansion tank under it that could work but I believe neither of those things is recommended.

Phase C)
-Replace zone valve manifold and zone valves

Phase D)
-Install Taco zone controller (any benefit other than aesthetics?)

Phase E) (this will happen with an insulation project, hopefully in the next few weeks)
-Replace non-oxygen barrier pex with oxygen barrier. At like 80% of it by lineal foot.

Phases B-E are all largely independent of each other and can be accomplished based on needs arising for repairs or whatever. Or maybe never do them if I replace the boiler, or retire the boiler if heat pumps get more reasonable. Or include DHW which would change things. Or a buffer tank that connects to both the boiler and an air to water heat pump? A man can dream about boilers, can't he?

Let me know if you think anything should be prioritized.

Zman

On the flange rotating, you might consider switching to a Taco 007. The standard flanges are opposite and the 007 is pretty inexpensive. Taco also has a universal flange that can mount in either position.

AdamInEvergreen

@Zman I certainly like the idea of just slapping a different pump in there...is it a valid concern that the inadequate hydraulic separation will cause excessive pump wear? If I reuse the existing I'll have a backup after installing the Alpha2. Although the pump consumes 3x as much electricity as a 007e it appears the boiler only consumes about $10/month in electricity (both pumps plus the boiler).

Also I've never pulled that pump but when I pulled the other one there was no flow check installed...I bought the flow check itself some time ago but it wouldn't fit due to surface corrosion on the inside so I reinstalled without it.

Lowering the pump speed (low on zone pump, medium on boiler pump) is working well for my smaller zones but main floor seems to take forever to heat up, especially when there is another zone running at the same time. Hopefully the delta-p will pick up on multiple zones open and crank it up accordingly.

Zman

How about this one? https://www.supplyhouse.com/Taco-VR1816-HY2-4C2A00-Viridian-Infinitely-Variable-ECM-High-Efficiency-Circulator-Less-Flanges-Universal-120V

AdamInEvergreen

Zman said:

How about this one? https://www.supplyhouse.com/Taco-VR1816-HY2-4C2A00-Viridian-Infinitely-Variable-ECM-High-Efficiency-Circulator-Less-Flanges-Universal-120V

Are you suggesting the Viridian for the zone pump and a 007 for the boiler pump? Or a delta-p pump for both (seems like they might fight eachother)? When you suggested 007 I found the 007e with universal flange:
https://www.supplyhouse.com/Taco-007E-2F4-007e-ECM-High-Efficiency-Cast-Iron-Circulator-w-IFC-Universal-Flange-120v-60Hz-1-PH

Zman

I would leave the boiler pump as is and adjust the speed to get the desired delta T. I think either the 007e or the one I posted would be suitable for the zones.

AdamInEvergreen

Got some new toys! Ive got a few more nipples in addition to those shown (bought the variety pack).
Current spacing (hand tight on threads so it will shrink a bit) :
elbow to air sep 2.75"
air sep to pump 5.25"
pump to elbow 5"

Im a bit stuck with the over all length. Any swapping I should do?