Insufficient heat from system

FrustratedandCold

Hopefully someone can help sort out my issue, which is not getting sufficient heat out of the primary loop off the boiler, and into a second floor heat zone.  

The basics of the house and set-up, are as follows:

3100 sq ft house, under significant remodel, including complete heating system replacement

Upstairs zone has about 200ft of 3/4 pex feeding 39 feet of petite 7 baseboard in 4 bedrooms and 2 small bathrooms, total just over 900 sq ft on that floor. Grundfos UPS15-58FRC pushing water into the loop. The upstairs has all finished and insulated walls, carpet floors and presently no doors on any bedrooms. The walls have only old R-11 and are not well air sealed, the attic has 10" blown in cellulose, which is close to sufficient as its been compacted.  This space should be able to be normally heated.

this is the only zone presently installed.  The first floor has open walls, mostly insulated (missing a few bays due to wiring be run through them, those will get insulated when wiring is done later today). This floor is currently heated to 65-68 degrees by the old hot air furnace so it is comfortable to work in. Eventually there will be 2 zones for the 1500 sq feet of this floor.

We did a blower door test, and a heat load study before beginning the project.  That study told us we could lose 95k btu/ hr based on the air leakage and prior insulation.  So a Burnham Alpine 150 was recommended along with a 60 HTP superstor.  We fired up the system a couple weeks ago, and have not had any issue with hot water supply, without the heat being on, the hot water is nearly endless, even running it out with a garden hose for 25 minutes it doesn't run out. 

The issue is the boiler short cycling, and not getting sufficient heat to the upstairs zone.  Since turning on the heat last Tuesday, the boiler has now cycled nearly 2000 times, and the heat zone has never stopped calling for heat.  attached pictures may help, but my installer has basically told me its as good as it will get, and has stopped taking my calls. I feel I need to resolve the issue before I close the walls and the ceilings on the 1st floor, in case something needs to be changed.

The boiler piping is all 1" copper, with a taco 0015 circulator.  There is about 6" of piping before the closely spaced T's and the IDWH take off is placed outside the primary loop. 

Basically the boiler comes is always running, but runs at near full output, the supply and return water temps come to whatever the set point is based on the outdoor sensor, and then it stops firing, and the system very quickly cools to the 130-140 range and the boiler ramps on again.  There is heat coming from the upstairs baseboards, but not very much.  It seems to not be able to get warmer than 66, degrees up stairs, and the baseboards never get more than kind of warm to the touch, maybe 110 degrees.  I have had 3 guys who install other brand systems in to look at it, and everyone says it should be working much better than it is. 

Please help me, and if you are local, please get in touch as I would happily have someone knowledgeable and experienced in the Chelmsford, Mass area come and fix this issue.

Weezbo

mannnn,....

i wish you'd have turned the thing up a bit more its still at Least 36 below zero outside and my van Still won't turn over....

now i am late for an appointment ....

look , even if you have a heat loss calc that does no good whatsoever if the heat is turned on without the rest of the heat instlled and the windows and doors and lid Buttoned ..



trust me on this one ...

thats the third time i tried to start the van .. and it still won t go ...

Zman

Slow Down

Trying slowing down the 0015.

I am thinking you are either overpumping that circ or you have an air lock in the zones.

I think that Kcopp who post here quite often is in your area. He is really quite knowledgeable.

Carl

Rich_49

Dennis Foley

Dennis Foley Plumbing Inc . , located in Somerville should certainly be able to help you through this .  Would you by any chance be willing to provide the name of who did this work ?  Could you also post a copy of the room by room heat loss and the amount of baseboard in each of the rooms that are completed ? Name the rooms as they are noted in the heat loss report .

FrustratedandCold

overpumping

Carl,

we switched out the 0015 for a 007 earlier today, and it doesn't seem to change anything.  the boiler still cycles back to firing within 30 seconds of ending a cycle, and not much heat reaching the baseboards.  but I do believe you are correct about it overpumping, as we had already set the 0015 to slow before replacing it, and that is where we saw the best performance.

I have thought of airlock as an issue, and it seems the 0015 was a major culprit of this. I fear there are also too many elbows in the pex line, there are 25, which is certainly adding a great deal of head pressure. hence the grundfos pump.  I have vents ready to be put in place on each baseboard if nothing else seems wrong with the piping.

Jean-David Beyer

I have had 3 guys who install other brand systems in to look at it,

I am a homeowner and have only one suggestion for fixing this. That is that you should find a capable installer, preferably one with experience installing and maintaining boilers like yours.



What I wish I could tell you is how to find such an installer. I did a lot of things to find mine, and got the wrong one. When his technician came out for the first annual service, he could not tell, by looking at it that it was a gas burner, not an oil burner. He did not come with the parts needed for maintenance (igniter, gasket set, etc.) He did not have a combustion analyzer. He said he was allowed only 15 minutes to do the service on it. I had read the manual and it seems to me that between one and two hours are required to do the initial one-year service. (The annual service is still a little over an hour from my new heating service contractor.) He told me that gas boilers needed no maintenance. I sent him on his way in less than his 15 minutes.



I now have a better one. He knows it is a gas boiler. He knows to bring the annual maintenance kit with him. He no longer needs to be reminded to bring the combustion analyzer. The only thing he will not do is check the pressure relief valve on the boiler and the P/T valve on the indirect water heater. They seem deathly afraid to check those. I guess they are afraid if they do that, that they will not shut off even if you do this from new. I purchased a new pressure relief valve for the boiler and keep it on hand for the boiler, but I have not done so for the indirect. Not sure how long the probe has to be for that. (W-M indirect, probably by Triangle Tube).

FrustratedandCold

Who done it?

Dennis, I won't post who helped me put this in.  He was a friend, and I think has other issues at the moment, and never really gave my project the attention it needed.  I have installed full systems before, really loved the GB142 I personally installed at my last house, but went with the alpine at his recommendation, since we have interesting water here, and it can do a number on the aluminum heat exchanger after a few years.  The supply house recommended against the 142 as well, which I thought odd, but apparently they have seen several need replacing in my town after about 8 years. I have been doing most of the install work myself, following the diagrams given to me, at his direction.

As for the heat loss calculation.  I can try to scan it and upload it later, but it was done by the same person who did my last house, and it was terrific.

Zman

007

The 007 is too small for the application. Those exchangers can be pretty finicky about flow. I would think the 0015 on speed 1 or 2 should do the trick.

What kind of delta T are you seeing on the zones. Have you tried to power purge them?

Carl

knotgrumpy

You should...

Turn this circulator so that the motor shaft is horizontal.  It looks like it is vertical now.



knotgrumpy

FrustratedandCold

pump

the 0015 started making horrible noise today, so we replaced it with a 007 that was lying around so we could take apart the 0015 and see if it had junk in it or was going bad.  have not put it back in yet.

FrustratedandCold

ok

sadly though, that is the only thing actually working correctly.  I can turn it later though.  Why is that significant though? from what I see in the taco information, as long as the electrical box is not below the motor its ok.   I'm just trying to understand with this question, its not a big deal for me to rotate it.

Rich_49

Shafts

on all circs should be horizontal .

PLUMMER

Webzine gonna love this

Can you or have you monitored S&R temps. You said bad noise from the 15, was it just cavitating? Which confirms another experts diagnosi. The 15 on low or med I think fits the bill per spec. That's the IDW for huge initial dump loads for sure. It'll be fun if you ever change a cartridge....looks good

Bob Gagnon plumbing and heating

Boiler Fix

I would try again to get the installer to fix the problem, he should be able to get Burnham on the phone and they can lead him through the problem. I sounds like it could be needing an adjustment of the parameters. Did you get the boiler from Peabody Supply? They should be able to get another contractor who works on Burnham, if not contact Burnham, they should have a list of qualified installers.



Thanks, Bob Gagnon

Dennis Foley

Check heating parameters

The boiler requires that 0015. The pictures don't really show how everything ties into the primary loop., What are all the headers to the left of the DHW doing, and how do they connect to the system.

You might just disable the outdoor sensor in the control for now, since the house is under construction= in other words, everything may be working the way it's set up to work, but the boiler reset isn't giving you hot enough water to satisfy your present heat loss. Just go into the control and disable the outdoor sensor and see how that works. or change the heating parameters.

Steamfitter66

Sounds like you air locked.

Your air eliminator should be in the primary loop, not the boiler loop. Air doesnt know it needs to turn right at the T.

Rotate your boiler pump to horizontal. The bigger pumps really dont like being installed that way. The noise you heard was probably a bearing.

In your primary loop I dont like to have return header on top with no way to vent air. If you had your supply on top you would only need one vent.

Steamfitter66

Sounds like I doubled down

Jean-David Beyer

I am not sure I understand this.

"Your air eliminator should be in the primary loop, not the boiler loop. Air doesnt know it needs to turn right at the T."



In my (primary-secondary) system, the boiler manufacturer says to put the air eliminator in the system loop, not the boiler loop. This agrees with what you say.



The reason this puzzles me is that my system loop (really two parallel loops, one for a baseboard zone and one for an in-slab radiant zone) runs at fairly low temperatures (from 76F to 135F depending on the zone and the outside temperature), whereas the indirect water heater that they say should be piped across the boiler loop runs at a quite high temperature (170F to 180F).



Now my system has purge valves for all the loops, so all the big bubbles come out when it is purged (which is seldom, only when air gets into the system such as when I had to replace a circulator).



The baseboard zone is above the boiler and the radiant zone is below the boiler, so all the bubbles end up in the baseboard or in the indirect (tank within a tank). The indirect can let any air that accumulates with a little automatic float-type valve. But the upstairs baseboard has to get the air out one of two ways. If the flow up there is high enough, the air may be trapped in the water and pushed down to go through the air eliminator. Or it can be dissolved out and then eliminated as it goes through the (microbubble type) air eliminator. So for actual bubbles, having the air eliminator in the system loop is the way to go, so they do not have to go downhill through the boiler to get to the air eliminator.



But for the dissolved air to come out, it should be in the system where the water is the hottest, and that would be in the boiler loop (at the output of the boiler). With it in the system loop, it takes several months to get the last little bit of air out. Luckily, this is not a problem every year, only when the system must be opened up a little.

Steamfitter66

You could install it there but the best place is

In the primary loop about 5 pipe diameters down from the boiler loop tie in. It will the see the low pressure if you are pumping away. Some of the micro bubbles will reabsorb and some will be captured.

When piping hydronics air management must always be considered. If I was an air bubble where would I go. I.m stubborn and I can't be pulled I must be pushed be water. Gravity is my friend and he will help me stay at the top.

So you have to have air removal between the return and the pumps.Assuming you have your pumps on the supply.

Jean-David Beyer

the best place is In the primary loop about 5 pipe diameters down from the boiler loop tie in.

That is about where it is. Pumping is "away".



My only annoyance is that if some air gets into the upstairs baseboard zone, it takes months for the Taco 4900 series air eliminator.



https://www.taco-hvac.com/uploads/FileLibrary/100-2.9.pdf (page 2 and top of page 4)



to get all the air out. If I were designing the system, I would probably put a coin vent at the end of each baseboard section up there (there would be only two). It is a bit tricky because there is 64 feet of horizontal 1/2 inch copper tubing up there. The good thing is that the Taco 007-IFC circulator is probably too big, so the water flow does bring a lot of the air down to get eliminated. But it is the little bubbles that take forever to get out, and they make a noise that irritates me. This year I had no problem because no air got in that needed to be removed.

FrustratedandCold

Headers

to the left of the HTP are the domestic water, the cold feed into the HTP is 1" as is the outflow, the 1" goes into the or out of those manifolds.  seems we are constantly changing things in bathrooms, so wanted it to be easy to shut them down individually.

As for the 0015, it just gave up on us, so need to take that to be replaced.

I have tried the outdoor sensor enabled and disabled, does not seem to make a significant difference.  We have played with response times, high limits, low limits and the short cycle delay, but we simply do not get the heat out of the primary loop.

Last night I did a bunch of measuring of temps all through the line, looks like I get about a 12 degree drop on the run of baseboards, but when its only getting there at between 120 and 130 even though the boiler output is 180, its hard to heat the space. Last night the inside temp steadily fell to 66, while the remainder of the house not being heated by the radiant system stayed at 65, where it is set.

One person I talked with suggested I replace my single run with 2 runs, and either separate the zones, or balance them. He had me pressure test the heat run, and its at 20 lbs right at the pump, and only about 8-9 on the return side. To me it says I have just too much resistance in the run.  Currently the run is just over 200 feet including baseboards and the vertical length, with 25 brass pex elbows in the line. 

I can change the run, remove most of those elbows and shorten it by at least 25 feet, but wonder if I'm going to go through that, should I replace the 3/4 pex with 1 inch?

Steamfitter66

Not a big fan of the 4900

I feel the Sarco or Spirotherm tend to do a better job.

Coin vents and baseboard Ts equal happy customers.

Dave H_2

flow and pressure drop

Did some quick math based upon what is installed.



I found that you need about 2.2 gpm (based upon 39 feet of baseboard at 550 btu's/foot)



The pressure drop of 3/4" pex and 25 elbows and running at 140 degrees comes to about 12.4 foot of head.

So, a 007 is too small of a circulator

The 0015 on speed 1 is perfect, of course if we are estimating some of this info, speed 2 may be better if we are under estimated.



I don't think changing the size of the pex will change much or eliminating elbows.



Dave H.

SWEI

12.4' @ 2.2 GPM

A 008 will do that, as will most of the ECM smart circs.

FrustratedandCold

ok off i go

Off to the supply house I guess.

I also spoke with Ron from us boiler about the issue, he made three suggestions, re-pull the pex with as few elbows as we can, and eliminate any of the run possible, I will do that. Next was try a bigger pump in the heat zone, and third, change my piping beyond the boiler loop to 1 1/4 rather than 1"

He also suggested that a bigger pump on the superstor would be good.

Looks like I have a busy day shaping up, thanks for all the help so far.

Zman

Nuts!

Why in the world would you start randomly swapping parts?

What you need to do is collect data in order to find out what is going on. Go out and get a nice 2 temp clamp on digital temp gauge. Get the system running and see where you have circulation and where you don't.  The delta t on the various loops will tell you everything.

If you have truly given up on figuring this out yourself, hire someone to figure it out.

Who is this Ron?

Worst advise ever!

Carl

FrustratedandCold

out of my mind indeed!

But that is not really relavent in this case.

I put temp and pressure gauges all over the place before getting the field service rep (ron) on the phone. Had temps showing on the supplay and return at the boiler at 170-180 and equalizing causing the boiler to stop heating.

Have not seen temps going out of the supply to the zone above 132 and typically only around 120. The return side is consistantly 12-15 lower than supply. And that is with temp gauges

The pressure at the zone pump holds steady at 20lbs, and at the returnat 8-9 lbs.

So correct me, for I may be wrong, but the pressure issue is the biggest problem, as it means I have over 22 ft of head there.

So I may be mistaken, but I am not getting sufficient flow out of the boiler loop into my heat zone because of the reduced flow and insufficient pump size for the loop as installed. I have the ability to change that now....but will not in 2 days.

Dave H_2

This pressure drop

is just for the zone, if the circulator needs to pump other devices, then the associated head loss must be added.



I couldn't get a clear picture of the piping to see the pump and piping



Dave H.

Mark Eatherton

Uhm, excuse me Knotgrumpy, but...

Looks like a water meter with a pressure reducing valve, and NOT a pump to me...

But I could be mistaken :-)



His first and second photos show a BLACK circulator improperly installed, but the picture you reference is NOT a pump.



Upon closer inspection, there COULD be a green circulator standing on its head in the shadows of the indirect... But can't tell for sure.



ME

Zman

Air lock

I am glad you came clean about your mental state.

You should only need about 2 gpm for those radiators. It looks like you would be designing for 2 gpm at 10 feet worst case. Your circ is big enough.

If you cannot get the 170 degree supply to go into the heat loop, you have no circulation  at all. Stop everything and find out why.

Is the pex kinked or are you air locked?

Can you isolate the loop and purge water through it.

Carl

FrustratedandCold

air free

All my zones have full isolation and flush capacity, the zone was isolated, and flushed with street presure more than one. Was vaccuum filled, and circulated indipendent of the boiler and hot water piping. We spent two days looking for air locks and installing vents at end of each baseboard.



I wish it was just air bound, that would be easier to solve, I think.



Half way done re-running the pex today.

Ironman

Changing header Size...

Might be the biggest factor in correcting your problems.



The manifold in this piping setup must be sized as close as possible for a flow velocity of 2 fps. With the 015 circ (which is right), you're moving around 15 gpm through the common piping of the manifold. That translates to a velocity of around 6 fps with 1" cu. tubing. The zone circ cannot overcome this and you actually have reverse flow between the closely spaced Tees. You have hydraulic interference in the manifold which would be eliminated with proper sizing.



You really should have 1 1/2" for the manifold to get close to 2 fps, at least that size on the common piping between the Tees. 1 1/4" leaves you at 4 fps.



Then sizing the zone circ properly and removing as much resistance from the piping as possible will help.

Zman

Check valves

Bob,

I agree that the header design should be bigger.

It does the same thing with a 007 on the boiler loop which makes me think it is not the problem.

Do all the zone circs have check valves?

It is possible you have backflow through the other zones.

You could test this by closing the isolation valves on the other zones.

Have you verified the operation of the zone circ.

Carl

Weezbo

is your furthest run,

the beginning of the supply to the zone?



i tend to use bend supports on pex rather than fittings unless it is at a station , or it is potable water .



i eliminate 90's as much as possible i even bring the pex thru the floor and bend it into a

"reducing T, tipped about 15 * into the room with a fitting copper to thread bushing and spin in a coin vent ...and either run my base board thru the partition to the nex t room or feed a piece of pex in underneath that swoops up into both rooms and then bends back to meet a coupling with an adaptor once again as in the T with coinvent operation that was first encountered .

Like you , purging is a Big Deal with me .



the next coin vent will be on the last coupling that heads back to the boiler where ,

i use some regular type M to the T tipped back into the room with a fitting adaptor back to pex that rolls back into the floor .



that will eliminate useless fittings....



when i get to my boiler wall i drill a large 2 and 5 or 2 and 9 and roll the pipe into the wall behind the rock that should not be there because it is in rough in stage and has yet to be tested and inspected. then i use a copper 90 with an adaptor to pex with copper stub outs arranged it the pattern of my choosing for each zone ,



then with the stub out it can be rocked . sometimes i will use a copper nipple of varying lengths to marry up the pex to copper ...



for the most part i use zone valves and 1/2" pex ...



you need to pay close attention to insulation detail on the rim and box beams if it is not spray foamed then make very certain you have zero tolerance for Any daylight showing and the same for anything that looks like a empty space in the insulation.

keep plumbing out of outside walls ...even if insulated it is not where it belongs ...within the envelope is the place to be with everything other than a Vent.



tell me more about these supply temps as i cannot quite see many gauges in the pics ...



perhaps , our lives are some view on the things that are happening rather than what we want happening at the moment ...



could also be that the lesson is for others benefit more than our own..



Weezbo.

Ironman

Circ

Carl,

According to his pics, there's only one zone connected right now.



If the calc that Dave H gave of 2.2 gpm @ 12' of head is correct, the 15-58 can due that on high speed.



I'm still not completely convinced that air binding may not be involved too.



The check in the 15-58 may be stuck too. I had one just the other day do it right out of the box.

Weezbo

Iron man ,

have you ever encountered a header that was valved off with circs, that suddenly , inexplicably , started to growl ? i tend to think , just off hand, that the other risers on that set of power eaters has air ....



*~//: )



the risers to the pex if longer could have gauges on them and beneath the gauges ,

purge valves ... above the circs , say for an example , and it wouldn't hurt the system a bit.

then say, it had the top valve shut off at the circ and all lower valves opened ... with the power off for a bit and filled to the top of the pex adaptor above the gauge,...

until water or fluid ran out ...using the same process of valve release of fluid or lashing up a hose with a bump from a pump with a bucket of water ..

then for certain closing the valve above the cir would top off the water and let out most air in the header ... to atmosphere ....



......

FrustratedandCold

check valves

yes every pump in my system has a flow check,

Every circ does work, and I have isolated every part of the system to figure out where stuff is and is not flowing.  Header size is apparently an issue.

FrustratedandCold

Header rebuild

Definitely going to rebuild the headers, which will also likely mean the rest of the near boiler piping as well. I will switch the 1" to 1 1/2" when I get there, for now trying to get sufficient flow up to the second floor, so the walls of the first floor can be closed. 

So far, I have re-run half the zone, starting at the manifold, without a fitting other than at the baseboards, and removed about 30 feet of pipe in the run.

Unfortunately this meant putting the supply side of this 1 run in an exterior wall.... BUT, I used to own and run an insulation company..... so I'm pretty confident that the PEX will be really well insulated.... there might be a little foam going in, but not directly against the PEX. From my experience, PEX need to be in an insulation sleeve before it gets foamed so that it can still move, otherwise it eventually squeeks

FrustratedandCold

weezbo

I put gauges on the pipe, and in the draw-offs all over the place after taking the pics posted.  But here is the useful part of that info.

near boiler loop was reaching 170-180 depending on the target based on outside temperature very quickly.

when the dhw was isolated from the system, I was getting 132 at the header for heating zones if I was lucky. return was routinely 12-15 degrees lower. 135 at the header translated to about 130 at the 1st baseboard I say about because I had to run up 2 flights of stairs to quickly get a read, and i'm not as young as I once was.

If I opened the isolation valves fro the DHW, it would get all the way to 160 in fairly short order.  This is likely a stuck flow check issue, but demonstrates that the heating manifolds are certainly not the path of least resistance presently in the system. I did try just for argument sake connecting another zone to a new loop of pex, 100', still in a coil, sitting on a workbench right next to the boiler, this got me longer duration of 130+ degree water at the manifold. but the heat is clearly not making it to that manifold. 

Then I promptly disassembled the upper loop, and the dummy loop to start re-running the zone. 

Since I want to ensure air is not an issue, coin vents are being added to each side of every baseboard today.

The beginning of the zone is nearly identical to the end of the zone, but the start of the zone is on the north facing side of the building.

RobG

Closley Spaced Tees

I cant tell from the photos but if you have a valve in between the closley space tees, if so shut it and see if the flow goes through your baseboard loop.



Rob

ckeefer79

Check system settings

When my Alpine was first installed, the factory settings were completely wrong.  The touch screen will allow you to make adjustments.  First place I would look is under the "Manual Control" menu and touch the "Auto" button to confirm the boiler settings are allow the control board to manage the boiler fan speeds.  Based on what I am reading by your description, the boiler is set to run at "High" firing rate which will cause the water temp to over run the preset temp and turn the unit off, however it hasn't satisfied the t-stat so the unit will kick right back on after the cool down cycle (about 30 seconds), ramp up to full fire, heat the water to the preset, overrun it again by 10+ degrees and fire down.  It will cycle non-stop like this.  The "High" and "Low" setting under this menu are for testing output but I found when my installer left, it was left on "High" and for the first couple of nights my house was very cold and the boiler cycled a lot.



Also, make sure your "Central Heat" diff above is set to 10+ degrees, I have noted the Alpines seem to overrun their preset by 2 to 3 degrees on a good day, and the key is to get the boiler to modulate down the RPMs instead of shutting down completely.



If you don't know how to get into the "adjust" menu, it's covered in the owners manual really well - the passcode is 076.