no heat calls

duffy_4

went on a no heat call,6 unit building baseboard heat each unit.140,000 ci boiler,6 circulators feeding 3/4 "copper supply returns all piped off common header and common 11/2" return header ,seems the units piped at end of supply header get no flow if the first 3 pumps are running ,would like suggestions on corrective measures for this, its not piped pri/sec.all pumps are off individual relays so i will add a taco 6 pump relay panel so i can easily identify which unit is calling,but have to fix flow imbalance first,attached a few pics,thx for the suggestions.....duffy

duffy_4

no heat call

pics didnt work ill try again

Paul48

Circulators

What are you using for circulators?

duffy_4

no heat

each zone has a grundfoss 3speed 15-58,i didnt install this job just called out to fix the intermittent no heat issues .....thx

Steve Whitbeck

blockage

You must have a blockage somewhere between the returns and the supplies.

That 1 1/2 main is not a flow restriction - No need for  primary secondary.

Any chance the air seporator is plugged with dirt?

You have a blockage - the strongest ( least restricion to flow ) loops are winning the water flow war.

Try flushing water from the return main through the boiler to the supply header.

Hook a garden hose to the return and feed water into system from a good source, drain water from the supply, turn all of the loop ball valves and feed vavles off.

should come out with no resistance to flow.

kcopp

What speed...

are they running at? If they are all on full bore (spd 3) they may be getting too much flow at first. Drop down to speed 2 and figure out what you actually need for flow. Give us more info about the system.... baseboard on each zone&  length on each loop.

duffy_4

No heat

Thx Steve will try that when I get back there tomorrow ,with first three pumps after ais separator running the return gauges read 170,160 ,150,respectively and the fourth pump running return is at 100 and that unit gets no heat ,it is not piped reverse return,if I close return on 1&2 pumps flow increases into 4 th zone I tried adjusting pump speeds ,but I have no good way of finding out length of pipe runs,can't get into units easily during day,was thinking I needed pri boiler pump pumping into closely spaced tees and connect return into supply ,pipe boiler as secondary pumping into and outta branch s of tees ,just an idea thx

unclejohn

Is there

A 1 1/2 shut off valve at the boiler so you can bleed each loop. Don't know why you would want to add the taco 6 zone box the pump relays are not the problem. It looks like two of the return valves in the last picture are 1/2 way closed. Where you trying to force more water through other zones. Could the zones that don't feed just be air locked?With ourt a shut off in the mains it will be hard to bleed each zone.

Paul48

One

of those circulators would probably feed all 6 zones.

duffy_4

No heat

Yes I was trying to throttle down flow in those zones to see what it would effect,was thinking I might need circuit setters in the returns was looking at caleffi 8 on hydronic balancing , the relays and wirings a mess can't see it in pics but the relay have been replaced in whatever zone wasn't heating owner kept swapping out thinking it was the problem,zone box would let me know which zones is calling easily and clean up wiring ,but your right its not the problem,you think pri sec piping not needed just balance flow in each circuit with all calling ??...thx

duffy_4

No heat

Your probably rt Paul ,thinking I woulda used smart pump and zone valves myself,owner thought pumps were to small since old boiler had 6 b&g series 100 ,go figure,I bled everything no air noises

Paul48

duffy

Can you at least determine which have to be your shortest to longest loops. Just use the things you can see. These 2 apts. are closest to the boiler and the circ gets set on 1, and so on.

unclejohn

Will each zone

Heat separately?

duffy_4

No heat

Will try figure out which loop is longest and which shortest and guesstimate ,bmst loops shortest ,then first and then second floors ,each zone heats fine if isolated I'm think inking its all just imbalanced as bsmt apts call for heat the least and top floors probably more often,just trying find best way to do that without coming up with big bill for owner,is it a repiping issue or something else thx for your input,the return temp gauges on the loops let me know if I'm getting flow on each zone,but with first three pumps running I get no flow past the fourth tee pipe is cool to touch if I turn on fifth pump in the series I start to get hot water past the third tee.that was situation yesterday ,will head back there tomorrow and do little more troubleshooting .thx for suggestions

icesailor

Lazy Flow Syndrome:

I think that you suffer from ME's Lazy Brother-In-Law Syndrome.

First, you need to find out has it EVER worked properly. If it didn't, it needs to be swapped to some form of reverse return. If multiple speed circulators, turn the working ones down, and the non working ones to "3".

But find out somehow, if it ever worked. If it did, you won't have to try to re-invent the wheel. Just figure out what is wrong.

Is it possible that those circulators were replaced? That it didn't work with 007's and now, have multi's to try to solve the problem?

My first rule of troubleshooting is "Did it work when new"? If it did, I look one way. If it didn't, it's another path to take. Don't over think the problem until you know what the REAL problem is.

Also, take those boiler drains out of those supply and return ends and replace then with pressure gauges. You can use cheap Tridicators but you won't get much of a temperature reading. The pressure differential pressure may tell you something. It's convenient so use it.

northernboiler

System pressure or very high head pressure loop

A couple of thoughts just crossed my mind:

What is the system pressure reading at "standby", nothing running. Then what does the pressure do when the pumps start to go?

Is it possible, however unlikely, that the remaining loops have an abnormally high head?

Or, maybe, is the radiation piped in a venturi?

SWEI

pumps or valves

Given the fact that pumps are already in place, and that circuit setters would almost certainly be needed along with zone valves, I'd seriously consider using an ecocirc e3 on each zone instead.  Just dial in the speed for the ∆T you need and let 'em rip.  They're so small they don't come with flanges, so a bit of prefab is necessary to make drop-in replacements.  We typically sweat them to standard 1/2" unions on new installs and skip the flanges altogether.

Paul48

ecocirc

SWEI......It looks like they top out at about 10 ft of head?

SWEI

e3 curves

~5.5' for the e3-4 (aka Laing E1) or 10' for the e3-6 (aka Laing E3.)  But when you look at moving 1-2 GPM through a zone they can work in places one might not expect -- and consume only a small fraction what a 003 or 005 will.  The savings from eliminating a balancing valve and the convenience of being able to dial in the perfect speed make them worth a look.

Paul48

Making Assumptions

Six identical apts, sharing the 140000 btus. Longest loop at 250ft of 3/4", puts the head at 15'. I know..... there's a lot of assumptions in there.

Ironman

A Lot of Good Advice Given

I tend to think like "Ice". Did it ever work right? If so, what's been changed? And like Steve said: there may be a blockage, especially in those loops going underground.



One other possibility: are all of the pumps pumping in the right direction? If one of them is wrong, it will mess up flow in the header from that point on.



If all else fails, it doesn't look like it would be that difficult to supply the header from the other end to create reverse return. But, throttling the valves should have given some indication if that would have helped. Or so I would think.

SWEI

I made some assumptions as well

140,000 BTU firing rate = ~116k output = 1.94 GPM average flow per zone at 20F∆T.

Paul48

Conservative?

200 ft x 1.5 x .04 = 12 ft head @ 1.94 gpm

duffy_4

No heat

Old boiler had 6 bg series 100 pumps running,I guesstimat longest Run approx 200' (20' up and back then I measured perimeter of building plus elbows up and down).will take close look at pump orientation when I get back hate to miss the obvious.the new boiler pumps and piping done this past fall,was thinking of just reverse return piping ,haven't used those Eco pumps ,wanna try fix problem wo too much cost,will be there tomorrow afternoon ...thx for the suggestion...Vincent

SWEI

I don't believe

we know what kind of radiation is in use, so I could not even begin to estimate loop head.

icesailor

Pumping Away:

For all they went through, it's too bad they didn't put gauges on the supply side.

Its also too bad that they got cheap and saved the cost of a 1/2" Cop X Fpt adapter and instead, soldered the boiler drain to the copper tube. Always a way to make a nice job look cheap. Especially when the washer goes and you can't change the drain.

That said, figure out a way to put a pressure gauge on the supply header because I can't see above the circulators. Close all the feed ball valves but one, the one you can try to test. When the pump starts. does it get hot all the way around and is there an increase in pressure? Note it. Also, note the pressure on the supply. The differential will be FU'ed but see if there is any. It will give you some idea of differential pressure through the zone. Then, switch to another one. Repeat the readings, one at a time. Measure it all, one at a time. Then, try #1 and #2 together. See what you get. Then, #1 and #3. See what happens. Get a feel for what is going on. A problem you have is that the supply gauge isn't really reading through the system because the boiler is in the way.

I think that there has been a problem since the boiler was changed. I think that something was connected improperly and the installer wished the job, health, happiness and long distance. Now it's your turn. If each zone will work on its own, but some won't work with others running, it is doing something highly unusual. Are the only flow checks the ones in the circulator as IFC's? They'll Ghost Flow. Look for cross circulation, That's why you need to close the isolation valves.

Jobs like that require close quality time so you can get to know it.



Good Luck.

Steve Whitbeck

flow

That 1 1/2 header is plenty big enough to handle the flow of all 6 pumps running at the same time.

The boiler should have enough flow so no need for primary secondary piping.

Unless there is a restricion to flow between the supply and return headers all of the loops should be able to flow the same amount of water as if only that one zone was the only zone running.

sounds to me like there is a blockage somewhere.

Mark Eatherton

Blockage?

In my 36 years worth of spelunking around boiler rooms, I can count on one finger, the number of "blockages" I've personally seen in a closed loop heating system. And it was placed there by a well meaning boiler mechanic who was trying to stop the water dripping back into the boiler room he'd just gutted. He forgot to let someone (replacement crew) else know he'd stuffed a red mechanics rag into the main to stop it from dripping on him, and subsequently it got forced out into the system..



I found it jammed into a 1 X 3/4 X 3/4 copper tee. I had to cut the pipe and extract the rag using a 1/4" sewer snake. Almost busted the cable off it was jammed in there so tight.



I'd suspect either air binding, stuck/missing check valves, or possibly too much residual pump head left over on the shortest loops that is causing the other pumps to dead head on the return. I call this the SIggy Syndrome because he was the first to identify it as a real possibility.



If in fact there were a true blockage, one would NOT be able to power purge the circuit.



If it is actually air bound, power purging will cure that problem.



If it is residual left over head, try turning all pumps to low speed and see if flow is restored.



Remember, you only probably need 1 GPM per circuit.



ME

Paul48

Your

longest loops would not require a 3 setting on the circ. The 2 setting gives you 15ft of head at 2 gpm, that's plenty.

Ironman

Hmmmm

Actually, if we do as Dan has taught us and think like water, then all of those things (air, stuck check valve, residual head) are blockages. They're all "blocking" the water from flowing.



The 1.5 in. header should easily carry 18 - 20 gpm. The boiler is an even larger "bubble" in the road. So your theory makes a lot of sense. Especially given the fact that the trouble zones work when they're the only ones on.



It could still be sludge built up in the bottom of the boiler to the point of restricting flow. I have seen that on c.i. boilers where leaks were not repaired for long periods of time. That should also cause the "snap, crackle, pop" syndrome.



Just stirring the pot a little more.

unclejohn

Seems to me

If a check valve was missing or stuck open all that would happen is you would over heat a zone. Since each zone works by its self it can't be air. Are you saying that three pumps running put so much pressure in the return header that the other pumps can't push water into it? I would run one zone at a time untill the boiler cuts off on limit and see if any other zone heats with it. And see that the supply and returns are marked correctly, maybe somethings crossed up in the walls.

bill_105

This reminds me.

I know a guy with the same scenario. After pump replacement (zone valves)and tearing his hair out, he just happened to look inside the Spirovent. It was as if the mesh had been coated with wheel bearing grease

This was Nome,AK and the installers put in a huge concentration of glycol. It seems that a nearly 100 % dose of the stuff gummed up the mesh. I'm betting the installers didn't flush it out with water, then add glycol. So debris in the system stayed in the system.

I'm aware glycol isn't a factor here. But it would explain why purging would seem to remove all air. And the air separator here is about the easiest place to look for blockage

Charlie from wmass

I say check the Spirovent

it is an easy thing to check and most likely to cause a flow issue over time if not serviced once in a while. also drop the speed on the zones just to make them work more evenly.

icesailor

All Mixed Up:

Each zone seems to have it's own supply and return. If you try each and every one as an individual, you will find out if they are marked correctly.  You can also tell if hot water returns in more than one return. Check that the proper thermostat turns on its own circulator. Don't accept anything until you prove it. Note the return pressure on each and every zone as an individual. Then, when you start to turn other combinations, if you start getting pressure drops, you can then figure out what is wrong.

I'll bet that the original piping/wasn't like it is today. The problem isn't in the boiler or is it air, it's something that was changed in the piping. I'm sure that there is very little resistance through that boiler.

Something that I would try just to see what happens is to connect a double hose connection on the drains on the end of the supply and return 1 1/4" mains  to connect them together.

And someone knows that it is there. They just wouldn't be truthful about what it is.

Someone knows. If it is a replacement and re-pipe, it must have worked at sometime.

It's too bad that they didn't put gauges on the supply risers. The way it is, you can't really "see" much more than static pressure. You could go on a flier and guess that the drop on one side is half of the return but that's like unprotected sex. You never know what you get.

Like if it goes up 5#, it MIGHT have gone down on the supply to the circulator, to equal a 10# head.

Paul48

Spirovent

I think Steve's theory is very possible, and easy to check. It still fits, and can't be thrown out until it's checked.

Aaron_in_Maine

Spirovent

I would look in the spirovent too. I had a 3 year old system plugged up the spirovent because someone used potable pex for the radiant. The boiler was breaking down. The mesh inside the vent looked like a brick.

icesailor

If that's true:

If that's true, and the Spirovent is restricted, put a pressure vacuum gauge (-0#-0-+30#) and note the static system pressure. It should be 12# or something similar. Turn on ALL pumps. If it takes a significant drop, the Spirovent is restricted. And note the other side.

duffy_4

no heat solved

thanks for all the help and ideas on this problem,sorry it took while to answer but been busy and it took a while to solve,as you can see by the pics i found two valves with the handles twisited off in the units where i wasnt getting ant hot water on return side ,i went to building drained everything down and pressurized each zone on at a time with air compressor and two units where holding pressure initially but would bleed down over time ,the other 4 units air and water came right out return side,called owner he got me access to two unit and found the valves,he said he never new they were there and people in these units had complained in the past about apt not getting warm enough,the girl sleeping in the one unit told me when it got cold she would just turn on oven and open it,she didnt want to complain to owner,guys had the building for over ten years ..go figure repiped it reverse return set pumps on lowest speed and installed taco 6 pump control panel and cut out the valves all workin great thanks again for help