# Bad viscosity?



## redbeardplumber

I am Working on a simple residential boiler system. Burnham boiler, primary loop has indirect HWT, 2nd pump controls floor warming and inslab. 2 1/2 weeks ago the main pump went, I replaced. Then 2 weeks after client called and said he had trouble. Both pumps gone #1 ( new one ) and #2 old one. Seized. Propylene is very dark. I said it was the PP. Owner didn't think so and didn't want to pay for complete flush and eat cost of pump. So I put 2 new ones in again and have been waiting for a call. Pump # 2 went today. Poly b in floor. Am I on right track? Never seen this before with old glycol? Any other options I may b overlooking?


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## OldSchool

How's the pump for the indirect ... Did that go also or is it fine ?


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## redbeardplumber

OldSchool said:


> How's the pump for the indirect ... Did that go also or is it fine ?


No it went as well. The new one as well.


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## Catlin987987

What brand of pumps?


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## eddiecalder

Test the Propylene with a refractometer to be sure.
*** what is the % mix and is it inhibited?
*** Is there an secondary heat exchanger?
*** Fire tube or water tube?


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## eddiecalder

is the glycol burnt or is it a dye?


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## redbeardplumber

Catlin987987 said:


> What brand of pumps?


They are grundFos pumps


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## redbeardplumber

eddiecalder said:


> Test the Propylene with a refractometer to be sure.
> *** what is the % mix and is it inhibited?
> *** Is there an secondary heat exchanger?
> *** Fire tube or water tube?


I tested it at -15 celcius with a prism. What would a refractometer tell me, not sure what that is.

Water tube ( I believe) burmham.

No I'm positive it's burnt because I worked on system 3 years ago and it was much cleaner, no one else in.

Inhibitors.... Not sure. Would you always use inhibitors?


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## OldSchool

redbeardplumber said:


> I tested it at -15 celcius with a prism. What would a refractometer tell me, not sure what that is.
> 
> Water tube ( I believe) burmham.
> 
> No I'm positive it's burnt because I worked on system 3 years ago and it was much cleaner, no one else in.
> 
> Inhibitors.... Not sure. Would you always use inhibitors?


Refractor and prism same thing ...


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## eddiecalder

How are the pumps and zone valves (if any) wired?
Is there a bypass?


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## Gettinit

Are the pumps cavitating?


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## rjbphd

The ploy pipe are NOT o2 barrier tubing and will aborbs the o2 into the system and kills the pumps and any other iron bearing material... you must separate the ploy system with heating exchanger and use the stainless steel or brozne pump on the ploy side.. seen this many times when they pick the lowest bidder and now paying more to have the pipings redone.


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## redbeardplumber

Gettinit said:


> Are the pumps cavitating?


No sign of damage


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## U666A

redbeardplumber said:


> No sign of damage


Except for being seized and all...
:jester:


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## redbeardplumber

eddiecalder said:


> How are the pumps and zone valves (if any) wired?
> Is there a bypass?


No bypass. Zone valve opens for indirect HWT this pump runs all time. Floor warming and slab after mixer controlled by zone valves which turn pump on through fan control relay.


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## Gettinit

redbeardplumber said:


> No bypass. Zone valve opens for indirect HWT this pump runs all time. Floor warming and slab after mixer controlled by zone valves which turn pump on through fan control relay.


So the boiler loop to the indirect tank is dead heading for long periods at a time.


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## redbeardplumber

rjbphd said:


> The ploy pipe are NOT o2 barrier tubing and will aborbs the o2 into the system and kills the pumps and any other iron bearing material... you must separate the ploy system with heating exchanger and use the stainless steel or brozne pump on the ploy side.. seen this many times when they pick the lowest bidder and now paying more to have the pipings redone.


Agreed. 20 year old system, corrosive water, frying new pumps quickly. I think I will completely flush and talk in to a retrofit.


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## redbeardplumber

Gettinit said:


> So the boiler loop to the indirect tank is dead heading for long periods at a time.


No. Sorry. Not dead heading


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## Gettinit

redbeardplumber said:


> No. Sorry. Not dead heading


How is it not if the pump runs all the time until the zone valve opens? Maybe I misread something. 

I see RJ's point long term but just two or three years passed between you said the boiler water looked fine. Seems a little quick for this particular problem but I don't really know.


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## JDGA80

Was the amp draw excessive for the nameplate rating of the pump


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## Catlin987987

rjbphd said:


> The ploy pipe are NOT o2 barrier tubing and will aborbs the o2 into the system and kills the pumps and any other iron bearing material... you must separate the ploy system with heating exchanger and use the stainless steel or brozne pump on the ploy side.. seen this many times when they pick the lowest bidder and now paying more to have the pipings redone.


Or just install rust inhibitor


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## redbeardplumber

Gettinit said:


> How is it not if the pump runs all the time until the zone valve opens? Maybe I misread something.
> 
> I see RJ's point long term but just two or three years passed between you said the boiler water looked fine. Seems a little quick for this particular problem but I don't really know.


Sorry bad explanation. Not dead
Heading, the zone valve only controls the flow to indirect off of primary. 

RJ is correct but I messed up, no poly b I checked my notes, thinking of another system.

Getinit also suggested checking amps and I have not done that yet, but I must. 

High amperage draw would suggest blocked line or plugged impeller no?


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## redbeardplumber

Anyways thank you ALL for the info and help. No doubt these strange ongoings are usually something simple. :0


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## Catlin987987

Did you check the line voltage?


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## OldSchool

redbeardplumber said:


> Anyways thank you ALL for the info and help. No doubt these strange ongoings are usually something simple. :0


Next time post some pics ... So we can take a look at what's going on ...


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## redbeardplumber

Catlin987987 said:


> Did you check the line voltage?


Yes it was fine.


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## redbeardplumber

Ok, one month later.... I was in holidays.... He has replaced pumps again. I am lost. Here are some pics, hard to tell what's going on. Circulator 1 is on return, runs all the time on small boiler loop, off of loop is a heat exchanger... Not used anymore also off of boiler loop is a zone valve for indirect HWT. Circulator 2 is right below mixing valve for in floor and floor warming. 

To recap I was called out no hot water. Replaced pump 1. 2 weeks later replaced new pump 1 and pump 2 

Now again....he has replaced both

Amp draw ok

The only thing that changed on first pump replacement. Used to both be 15-42's, now they are 15-58's, and the old circulators did not have check valves, now they do.

Could the slightly larger size pump And check valve be starving pump of water? Don't make 15-42's anymore.

Still not sure what approach to take.


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## redbeardplumber

Pics


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## OldSchool

redbeardplumber said:


> Pics


I would rip that mess of pipe apart and start from scratch ...

Looks like some didnt know if the were coming or going ...


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## OldSchool

More than likely you got pumps running all the time ... Like Getin said ... Dead heading ... 

One or the other zone control or pump control ... So pick up a controller to stop the operation of pump and boiler when not needed ...

Seriously ... I would tell the customer that to fix this mess is to redo do piping arrangement and controls ..


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## redbeardplumber

Yeah, I understand OS....That is the thing to do

Boiler pump runs all time, but not dead heading...20 years...


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## OldSchool

redbeardplumber said:


> Yeah, I understand OS....That is the thing to do
> 
> Boiler pump runs all time, but not dead heading...20 years...


So what's going on the pump ? 

Motor ?
Impeller?
Body ?


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## redbeardplumber

OldSchool said:


> So what's going on the pump ?
> 
> Motor ?
> Impeller?
> Body ?


Seized


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## OldSchool

redbeardplumber said:


> Seized


So you took it apart ... From the body and you couldn't turn the impeller ?


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## redbeardplumber

OldSchool said:


> So you took it apart ... From the body and you couldn't turn the impeller ?


I took one apart the last time I was there and it took a lot for me to get it turning.... Weird.... It was 2 weeks, defenitly no damage to impellers though.


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## redbeardplumber

That's why I'm questioning what has changed....check valve and slightly larger pump


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## eddiecalder

Are there a flow switch and low water cutoff for the boiler ( can't view pics for some reason) 

At a minimum you need to keep the pump from running all the time. Wire in a relay they controls the pump on a call for heat.


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## TDB

Moder pumps are designed to deadhead. The 1558 can deadhead forever as far as I know

Air in the system will burn out a grundfoss since it is water lubricated. I suppose the liquid in the system could be a problem. I've never seen that happen before and I've serviced hundreds of pumps. I'd put new glycol and water in to start making sure system is purged well. Like somebody else said, make sure your pex has o2 barrier as well. All though your pump should still last years with domestic pex


Put taco pumps in next time and you won't have to worry about the quality of water burning up your pumps


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## redbeardplumber

TDB said:


> Moder pumps are designed to deadhead. The 1558 can deadhead forever as far as I know
> 
> Air in the system will burn out a grundfoss since it is water lubricated. I suppose the liquid in the system could be a problem. I've never seen that happen before and I've serviced hundreds of pumps. I'd put new glycol and water in to start making sure system is purged well. Like somebody else said, make sure your pex has o2 barrier as well. All though your pump should still last years with domestic pex
> 
> Put taco pumps in next time and you won't have to worry about the quality of water burning up your pumps


Yeah it's very strange, it is
not deadheading. Going to purge system, because .....who knows..... Changing whole system design at this point doesn't give me answers.

Thanks


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## eddiecalder

TDB said:


> Moder pumps are designed to deadhead. The 1558 can deadhead forever as far as I know
> 
> Air in the system will burn out a grundfoss since it is water lubricated. I suppose the liquid in the system could be a problem. I've never seen that happen before and I've serviced hundreds of pumps. I'd put new glycol and water in to start making sure system is purged well. Like somebody else said, make sure your pex has o2 barrier as well. All though your pump should still last years with domestic pex
> 
> 
> Put taco pumps in next time and you won't have to worry about the quality of water burning up your pumps



Are there any other manufactures that make pumps that are designed to deadhead?


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## Catlin987987

eddiecalder said:


> Are there any other manufactures that make pumps that are designed to deadhead?


The grundfos Alphas can. They will shut down if it deadheads, and spin back up when it's stops deadheading.


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## TDB

I believe all of them can deadhead without causing problems. They can deadhead because they are circulaters, not pumps. I don't remember the details but I remember reading it. I think I read it in a book called "pumping away". Something like - Circulaters rely on pressure differential and pumps mechanically throw the water. If a circ pump deadheads, there is no pressure differential so it just spins safely

It's been years since I read that book so I may be a bit off 

But I do know tacos and grundfoss pumps do not need wild loops if you want to keep them running. No reason to run them all the time but people still wire them that way if they don't know what they are doing


Delta t pumps are what we should be using anyways. But that's another thread!


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## TDB

OP. you should toss in some tacos next time you go out just to eliminate your water quality problem. They cost the same...


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## rjbphd

TDB said:


> I believe all of them can deadhead without causing problems. They can deadhead because they are circulaters, not pumps. I don't remember the details but I remember reading it. I think I read it in a book called "pumping away". Something like - Circulaters rely on pressure differential and pumps mechanically throw the water. If a circ pump deadheads, there is no pressure differential so it just spins safely
> 
> It's been years since I read that book so I may be a bit off
> 
> But I do know tacos and grundfoss pumps do not need wild loops if you want to keep them running. No reason to run them all the time but people still wire them that way if they don't know what they are doing
> 
> Delta t pumps are what we should be using anyways. But that's another thread!


Noooo.... I've seen dead pumps from dead heading on heating system wired wrong.


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## TDB

Not from taco or grund. Read the manuals...


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## rjbphd

TDB said:


> Not from taco or grund. Read the manuals...


Regardless, I've seen them


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## Catlin987987

TDB said:


> Not from taco or grund. Read the manuals...


Right from there manual
"Under no circumstances should the pump be *operated without
water circulation* or without the minimum required inlet
pressure for prolonged periods of time. This could result in
motor and pump damage"
http://www.pexuniverse.com/docs/pdf/Grundfos-UPS15,UP15-43,50-Installation-Manual.pdf


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## rjbphd

Catlin987987 said:


> Right from there manual
> "Under no circumstances should the pump be operated without
> water circulation or without the minimum required inlet
> pressure for prolonged periods of time. This could result in
> motor and pump damage"
> http://www.pexuniverse.com/docs/pdf/Grundfos-UPS15,UP15-43,50-Installation-Manual.pdf


Thank you... many can't read the pictures of the motor shaft placement .


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## TDB

I stand corrected!
I'm gonna have to go read a taco manual now


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## GWPlumbing

Hey RedBeard. You didn't get it fixed yet? Lol


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## redbeardplumber

GWPlumbing said:


> Hey RedBeard. You didn't get it fixed yet? Lol


No I haven't!

You better post an intro in intro section my friend, or the hounds will come.


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## theplumbinator

OldSchool said:


> I would rip that mess of pipe apart and start from scratch ...
> 
> Looks like some didnt know if the were coming or going ...


Thats exactly what I was thinking when i looked at those pics. What is mixing the different water temps back to the boiler on the return? I didn't see any flow manifold or mixing valves. Great way to shock a block and crack it.


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## redbeardplumber

theplumbinator said:


> Thats exactly what I was thinking when i looked at those pics. What is mixing the different water temps back to the boiler on the return? I didn't see any flow manifold or mixing valves. Great way to shock a block and crack it.


4 way mixing valve


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## theplumbinator

Cool, couldn't see one in the photos. Still looks like the guy that piped it Did it on a Friday, in a hurry with whatever fittings he had laying around in the truck.


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## Plumbworker

when you say you are replacing the pumps are you talking about the entire pump or just the cartridge impeller?


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## redbeardplumber

Plumbworker said:


> when you say you are replacing the pumps are you talking about the entire pump or just the cartridge impeller?


The entire circulator. The owner is now changing them, instead of getting me to rip stuff apart and find problem. Mystery.


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## Plumbworker

redbeardplumber said:


> The entire circulator. The owner is now changing them, instead of getting me to rip stuff apart and find problem. Mystery.


so you dont know if the stator motor windings are going or if the impeller is actually being seized? :blink:

Those circulators also have just a replacement cartridge if the impeller is seizing


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## slumplumber

Since the pumps use a water lubricated shaft/bearing (ceramic and carbon shaft bearings if I remember) you might have a lot of sediment floating around in the system which can seize the shafts, I would temporarily install a filter on the system to clean up the water/antifreeze I use a stainless steel filter housing equipped with a Taco 006 pump and two washing machine hoses to connect to the drain valve of the boiler and some other connection, the filter holds standard size cartridges (9 3/4" long by 2" dia) I start with a 10 micron cartridge and finish with a 1 micron both rated for 180 degrees of water temperature. You leave them on for a week each and it amazing what you find stuck on the filter elements especially on a new boiler install. Probably wouldn't hurt to check on the glycol concentration with a refractometer.


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## rjbphd

slumplumber said:


> Since the pumps use a water lubricated shaft/bearing (ceramic and carbon shaft bearings if I remember) you might have a lot of sediment floating around in the system which can seize the shafts, I would temporarily install a filter on the system to clean up the water/antifreeze I use a stainless steel filter housing equipped with a Taco 006 pump and two washing machine hoses to connect to the drain valve of the boiler and some other connection, the filter holds standard size cartridges (9 3/4" long by 2" dia) I start with a 10 micron cartridge and finish with a 1 micron both rated for 180 degrees of water temperature. You leave them on for a week each and it amazing what you find stuck on the filter elements especially on a new boiler install. Probably wouldn't hurt to check on the glycol concentration with a refractometer.


So ya posting again without a full intro??.. better do it as others will bite harder than me.


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## redbeardplumber

Ok here is update. I got the go Ahead to tear system apart because the amperage draw on circulator at high speed was ranging from.85 to 1.1. The sf amperage rating was .75. I was expecting to find a blockage..... Nothing.

So I replumbed the system basically the same. Yes ciculator on the return, but it is a short boiler loop. I installed a bypass this time. I also flushed entire system, and currently have it full of water.

The only thing that I found is that the expansion tank ( before circulator) did not have a hole in it, but it had so little pressure in it, it wouldn't register on gauge. So I put 13lbs in it .

Would this lack of pressure in tank and system at about 12 or 13lbs, cause a sort of vacuum and starve the pump of water???? This is the only thing I can think of.

Fired system up and the circulator now runs at .75 amps. Perfect. WTF!

Thoughts brothers.


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## redbeardplumber

Yes those are my socks drying on the piping. Lol


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## rjbphd

redbeardplumber said:


> Yes those are my socks drying on the piping. Lol


Besides those smelling socks... how many pumps on this system?


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## redbeardplumber

2 pumps. I on boiler loop and one after mixing valve for infloor and floor warming.


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