Pumping away ? I must have something messed up! Help

Badger896

Chasing alright

But I think I'm getting through the fog. The pressure climbs relatively quick at the start but then the boiler will heat and it takes a bit for the pt valve to pop.

So I think that if the ponpc before the pump is at 12psi and then the pump comes on and produces a press diff of 13 psi, since it can't add it to the ponpc and there is relatively no head loss in the piping or boiler then the boiler pressure is going to climb to 25psi the water heats the pressure climbs and the pop off spits!!

It's pretty much the same example in 'pumping away', there's nothing there to gobble up the pressure developed by the pump and the butt end of the boiler sees it.

There is also a lot of noise from water moving at the lower static pressure until the pressure builds and when the system is walking the line with the pt valve it's quiet.

I think the noise is coming from the velocity of the water moving and possibly causing the pump to cavitate. Not sure on that though

Badger896

Circ

I am going to try the 006, using the 0011 also explains why my delta is only about 10deg.

Tinman

I pipe

mod/con boilers exactly how the manufacturer recommends and, if I'm not mistaken, Triangle Tube has the boiler itself piped off the closely spaced tees (as the secondary loop) and the Prestige has very little pressure drop so a 0011 is way too big. I would refer back to how the installations instructions show these being piped.

Paul48

Couple Thoughts

That pump will add pressure based on its curve, not maximum. You are probably

destroying that pump, which then brings us back to expansion capacity.

SWEI

TT piping diagrams

show both options (see p. 21 & 22 in the PTS IOM.)  Direct piping/pumping is covered in more depth during their training classes, but requires proper pump sizing (which is unfortunately more than one can expect from the average installer.)

Gordy

Circs pressure differential

Will depend on the head the pumps sees. The larger the head loss the greater the differential pressure. If you install a 0-30 psi pressure gauge at the circs inlet, and outlet locations you could use the psi difference to calculate feet of head by taking the psi difference multiplied by 2.31 this gives feet of head.



Example if the psi difference is 5 psi then the feet of head conversion would be 11.55 feet of head loss.



As far as your primary, or boiler loop there is enough calculable information you can see to find the loops head and plot on the 011 pump curve chart.



As far as the system side is the 20 units of base board in multiple floors, or is it a one floor layout?



So if the inlet side of the circ drops to 11psi the fill valve will start filling the system for as long as the pump is running. But once the relief valve pops the pressure when you shut everything off should be higher than 12 psi. Since the relief dribbles at 30 I would think you would be in the 20 ish psi range until you bleed off some fill water back to 12 psi.



One of the possible issues with the pump on the return pumping into the boiler is the added differential pressure can pop the relief valve, but usually this happens when the system pressure needs to be higher because of system elevation to get psi over the top.



So in your case the 011 would have to add 18 psi to the outlet side to pop the relief valve on the boiler.

Badger896

Thanks for the classification

Soon I will be better than just an average installer. While I agree that I could have been more diligent in following the manual I also know that books and manuals such as 'Pumping Away' were written because of misinformation from manufacturers (not saying TT's information is wrong).

The reason I'm here is to try and get help in understanding the dynamics of what I did wrong so I can make it right for my customer. Ultimately preventing it from happening again. I am appreciative of the help I have rcvd.

icesailor

Big Pumps/Little Pumps:

Two pumps pumping on the same pipe  and together and through each other: Big pump pumping into a little pump wall raise the pressure. Little pump pumping into a big pump will not really raise the pressure.

What I have learned from experience is, the bigger the volume and velocity coming OUT of the pump, the lower the pressure will be going IN to the pump.

In spite of what the manufacturer says about the primary pump on the supply (pumping away), there HAS to be restriction or pressure drop through the boiler. NO MATTER WHAT!!!. If the fill valve (PRV) is between the suction of the circulator and the source of restriction (the boiler), the system pressure can drop locally (between the circulator and the boiler) to cause the PRV to add water. Shutting off the PRV feed and it not gaining water proves the point.

To prove my point, take a Watts 1156, connect it to a double hose connection and hose and boiler drains, and connect it to the return of the boiler. Leave the installed fill valve off.

It won't gain water. If that primary circulator was on the return (in spite of what the manufacturer says), there wouldn't be an issue.

In the late 1970's, early 80's, I went to a Emerson-Swan seminar put on by Taco and Heatway. I remember Dan telling a story about getting air into a heating system. Someone had a problem job and they couldn't stop the system from gaining air. Someone noticed that they could hear air being sucked into the large circulator through the seal. That's why it needed to be on the supply.

I don't remember if I agreed with that or not at the time but with all the well jet pumps I ever worked on, if the seal was bad, and the pump was running, the seal leaked water. I thought at the time, or thought later, that if the seal was sucking air, there was too much restriction on the return.

On Commercial jobs, they use "Circuit Setters" to determine the flow rate. By measuring the pressure differential to determine flow rate in the circuit. If you have 12# system pressure when static, and the outlet pressure on the system goes to 15 PSIG, but the inlet drops to 9# PSI, you have 6# PSIG of head pressure. If there is a PRV valve installed on the suction side of the pump, where the pressure is 9# PSIG, what does the PRV/Fill valve do? Add water?

Am I wrong?

I wasn't in application.

It also sounds like the Expansion tank is way undersized. I mean REALLY undersized. Connect a much bigger tank with the double hose connection into the system and see if the water adding improves. I'll bet it will.

SWEI

Becoming a better installer

Triangle Tube's training classes are one of the better deals in the business IMO.  You pay a couple dollars for the class, but they spend more than that on lodging and meals while you are there.

icesailor

Velocity Noise:

That noise is from Cavitation where the velocity of the water is slower than the circulator impellor is designed to go. The water is boiling around and in the impellor. When the pressure goes up, the boiling point goes up. The cavitation stops because of the increase in pressure.

Some old dead Wethead's figured out that pumps on the returns see cooler water and less cavitation.  A variable speed pump in a different location could be a beautiful thing.

SWEI

Let us know how it works out

At least 95% of the boilers we see are overpumped.  While I understand the "lawyers made us do it" mentality used for installation manuals, it's unfortunate that in order to maximize efficiency on a mod/con, you actually have to read between the lines.



I'm still concerned that your boiler is oversized, but that's a different conversation.

icesailor

Messed up?

"' "The reason I'm here is to try and get help in understanding the dynamics of what I did wrong so I can make it right for my customer. Ultimately preventing it from happening again."" "



You didn't do anything wrong. Wrong is not asking the questions. None of us were born knowing it. We all had to learn. We learn by our life experiences.

We learn by being stubborn when confronted with a problem that others walked away from. It became a challenge to us. When we figured it out, we learned and become better at whatever we do.

My wife has an expression. "Life can only be understood backwards. But must be lived forwards".

If you know more today than you did yesterday, you are having a good day. I learn something here every day. More than anyone will ever know.

"So many things to learn. So little time to learn them".

Badger896

Oversized

For what it's worth, I am going to try and see if there is a mechanical print available for the building by someone. I know the boiler we took out was 225000.

hot_rod

What size expansion tank

Was on the former boiler. Probably the new boiler holds less volume so the tank that was on the system previously should work on the new boiler.



Pumping away from the expansion tank will not cause the fill valve to add addition water IF the fill valve is also connected at that point



What about expansion tank pre charge, maybe the air charge is gone?

icesailor

Expansion Tank:

" ""I know the boiler we took out was 225000." ""

This string is getting so long, I can't find anything.

That "Extrol/bladder tank might barely work on a teapot heating system, but it will definitely not work on a heating system that has a cold start boiler with 150,000 BTU input. 

You took out a 225,000 BTU boiler and replaced it with that? Look on a bladder tank info sheet and it won't be big enough for a 225,000 BTU boiler. Somewhere, I thought I read that there were a lot of rooms in this building. With fin tube radiation on the walls with bypasses under the elements and run by something like a Danfoss Mechanical bypass valve operated by a thermostat on the wall with a capillary tube from the thermostat to the valve. It probably has 1" copper tube for the fin tube and the bypasses. It probably splits somewhere from 1 1/4" to 1". If this is so, the 011 circulator is probably what you need to feed this loop. The other circulator goes to the smaller loop. If I am correct, it sounds like an account I had for years that I learned a lot about hydronics. Except that there was a mechanical room to send heated water to different wings of the building plus a huge heat recovery/air handler. If it is at all like that, measure but estimate roughly how many feet of tube you have that you can easily locate. Use D/2(squared)X.0408X length in feet. It will give you a close amount of water in the system. The expansion tank must be able to handle it.

Is there any possibility that it had a primary loop with the boiler running on ODR? If it did, then those room thermostats controlled the individual rooms while the whole loop had constant circulation.

Believe this or not, as a troubleshooting method, if you have an old Extrol tank like a #39 or #60 (better), connect it into the system with a double hose connection and see what happens. I've done it more times than I can remember. A used but working washing machine connection is a plumber's best friend. Or at least this one.

Its possible that all your problems are around a undersized bladder tank. There's too much water expansion for the size of the tank and the amount of water in the system.

knotgrumpy

Where did you go?

Badger - What is the status?  Get any more pictures of the primary pump/feed/tank area?

unclejohn

The way

The extroll tank is piped on it's side like that that has to be a air trap if you are coming off the bottom of the air seperater like you said.

heatpro02920

I just glanced through the thread

OK, I seen this thread earlier but noticed the thread count and figured it was a resolved issue...



I have installed a bunch of TT prestige boilers, and I actually have a 175 in my own home...



OK- so we dont have any high pressure coils in the system? {no indirect water heater or other dual inlet exchangers}



So the first thing I would do is fill the system with the correct pressure {say 15psi, I'm not sure on your needs}, then shut the pressure reducing valve down and run the system, to make sure there is not a faulty 911s...



I also would change a few things about the piping, If you could give a little more info about your system we can come up with the best way to pipe it... Why such large pumps, them things arent going to be cheap to run? Do you need them for your radiation?



I use a grundfos alpha {set for delta P} on my primary and bumble bees {set for delta T} on my zones... I know for some reason the TT manual says to use huge pumps on the primary but I have had better luck with the alpha, I use it on every TT I do....



I also use a larger expansion tank on the 175's, in my house I have a 60 and it feeds 3 hydro coils...



I hate to say it, but I think I would want to start over if I went to your home for this problem, I would pipe it Primary secondary but I would keep my primary loop nice and short I would come out of the boiler and the only thing in my primary loop would be the circulator, very simple...



Just come out of the boiler pipe your left outlet into the circ, then out of the circ go into your close tees and back to the other side of the unit... Now you have your loop and the supply and return for your zones...



Come off the supply and on the way to your zone circs install your air vent, put the water feed and exp tank in the bottom of the air vent...



now out of the air vent go to you 2 circulators {do the math and size them correctly, use delta T circs if you can} now on the other side {your return} you come back from the zones and install your purge stations to complete the zone loops...



Here are some pics of my personal boiler in my home, I have changed this a bunch of times, its one of the first prestige boilers I installed, and I also started with a monster pump, now it has a alpha for the primary... The expansion tank isnt installed in these pics but I use a 60.. The piping has stayed pretty much the same, except it finished now and the alpha circ is installed...

http://i998.photobucket.com/albums/af107/turbobike1/IMAG0295_zpsec06f933.jpg

http://i998.photobucket.com/albums/af107/turbobike1/IMAG0298_zps3d208a3e.jpg



As you can see I jammed it all together, and I didn't follow all the rules on closely spaced Tee's, I had a very very tight space to work with, now where that free space on the lower wall is, sits my recirc piping and mini tank, also 2 feet in front of this board is a 170K BTU coal furnace, 3 feet to the left is a hybrid water tank and my well filtration system, on the other side is my water to water geo system { Not complete yet, someday Ill finish it}. rite next to the prestige boiler is my ru98 water heater... Needless to say I ran out of room in my boiler room, and I have already tripled its size since we built the house, and I have another utility room about 30 feet away that holds all my electrical, central vac, 1st floor air handler, whole house audio system, alarm, camera system, ect... So 600 sq feet of utility room and I need more...



My tees are close enough but my 90's coming out are too close to the tee's. Now the system works great and I have no negative effects, but I wouldnt do that at a customers house, this is my own home and I wont complain, but with a customer, the system can work fine, and some other contractor will come along and trash it because its not "by the book" ...



But anyway take a look at them pics, since you only have to do the work and pay for materials it may be a good idea...

icesailor

Hydraulic Separator:

Have you ever used Hydraulic Separators?

They are a beautiful thing and eliminate turbulence that you might have by misplaced circulators or closely spaced tee's.



Consider them as an accessory of the boiler and part of the primary loop. Then, the secondary loop is just like connecting to a boiler, the "old way".

If the above boiler had been installed with a Hydraulic Separator/Low Loss Header between the primary and secondary, I doubt that there would have been a problem.

Here's something. I think it originally came from Califfi. I know I had it with a bunch of stuff I had from them. Look at the drawings and read the article. I think it is around Fig. 7,



http://www.goesheatingsystems.com/hydraulic-separation

heatpro02920

icesailer, very true..

I love using hydraulic separators, but with my boiler I couldn't fit it and I did it with parts I had on the shelf for the most part, not a low budget project but I am cheap.. I agree the op's boiler would probably be fine with one, but they don't give them away, 2-1 1/4" tees is much less than what I pay for the taco 1 1/4" hydraulic separator {I think its just under $500] the vdx125 is the same price and probably a better product but never in stock where I shop, actually they are all kind of tough to get locally... Although it acts as a filter and air separator too which is a plus, just a hard sell when I have done 100s of ps systems with closely spaced tees that work great..

icesailor

Those things:

I don't do anything anymore. When I was, and the wall hung boilers I did, I considered the Hydraulic Separator as part of the boiler. I mounted it on plywood with F&M rings and plates. I just considered it as part of the "dressing" on the boiler.

I looked at a few problem jobs that would have worked well with separators. Anyone not knowing completely what they were doing, would have their butt saved with one.

It's just another form of idiot proof closely spaced tees.

bluey410

pressure change

What it seems like is happening is when your pumps xome on its dropping the return psi below your fill psi and adding water try piping your fill into the outlet of your pump

icesailor

Don't have?

They don't carry what you need?

Isn't there a Plumbers' Supply Co store near you? Anything that you want and use, they'll carry it. Of have it brought to you from New Bedford from their main distribution center.

If you want it, Jay or Kevin Jones will be sure that you have it.

And Lennie DiPasquale is in RI every Monday.

Whatever I needed for the last 40 years, they always made sure that I had it. No driving around because the store only had 8 of the items I wanted. So I had to go to two or more stores afterward to get what I needed. They are wearing out trucks going back and forth to their stores all over New England.

Low employee turnover. They treat their employees right.

If their happy in the store, they're happy to get the stock to you. Unless you are a guy that will drive 2 hours to Home Depot because the Watts 3/4" #340 relief valve is $.55 less than the local supply house, you'll like them. You don't sound like one of those.

I use that as an example because I was once in the Grand Poo-Bah of Home Depot in MA in South Boston, open 24 hours a day and you must be multi-lingual to work there (English is a second or third language).

heatpro02920

its tough out here...

I deal with 3 supply houses, and they are good to me, we have been doing business for years, I stock, a ton of fittings and parts for myself. I buy most of my materials online, I just put an order in for $3200 of webstone parts... I actually have a taco 1" hyd separator at the shop, and I used to have 2 of the 1 1/4" caleffis, but I used them this season... Normally I am 2 weeks out for installs and there aren't many emergency high end mod con installs happening rite now, so I can order the parts and get them pretty fast...



I really only buy my units and parts that I need rite away at the supply houses now, sheet metal, air handlers, tubing, boilers, furnaces. I buy local, But the fittings, valves, water feeds, controls, circs, ect I buy online and get shipped in... not just because its less money, but for the time it saves, I have everyone make a list when ever the order is going in, I order that night, its in my office 2 days later.

Locally a 3/4" male adapter is $2.40, I pay 88 cents... the difference is less subtle on stuff like circs and controls but warranty's are just as easy, I still deal with one person and I keep my costs down... I give the local supply houses a lot of business and I only use 3 small houses {well one is re michels but the other 2 I know the owners of personally}, it has worked thus far, but for some reason hyd separators are not on the shelves every where...





heres an example of something that happened today, I needed a 3" black tee, and 2 3" black 90s... My cost at the supply house was almost $100, I just checked to see what they would cost me shipped and it was $40 cheaper, I needed them today, so I bought them locally, but just an example, that is money I save my customers, or I can make myself extra, which ever way you look at it, its money that stays on my side of the table...

Badger896

Expansion tank resolved!!!

ok everyone, couple if things i installed a gauge beteew the fill valve and the system so i could see where the pressure was coming from. the expansion tank was definately too small and causing unneeded pressure climb but i also discovered that after closing the valve to the boiler when i came back the next day the pressure gauge i installed earlier was pegged, turns out the bypass ball valve was seeping water past it even though it was off!!! so i replaced the valve, installed a larger expansion tank and made sure my pressure relief valve was set at 12 psi (which was now easy with the gauge i installed earlier) now at full temp my pressure is around 14 - 15 psi... all the rooms heating and everyone including the maintenance guy is happy!!!!

i want to say thanks for the advice and help everyone gave!

Gordy

Bypass ball valve?

You mean for the fill supply valve?



And you mean pressure reducing valve set to 12 psi.



Did you check x tank pressure isolated from the system?



Glad problem is resolved.

Harvey Ramer

Pumping Away

Once again, the science behind pumping away from the point of no pressure change (expansion tank) remains intact.

This method of piping is rock solid.

Time and again I hear theories of the pump dropping the pressure at the inlet of the expansion tank and fill valve. CAN'T HAPPEN! As long as you have a functioning expansion tank and PRV, it doesn't matter what size pump you have, IT STILL CAN'T HAPPEN! 



Physics are what they are and they don't care what anyone thinks about it.



Harvey

Ironman

Exactly

And the laws of physics will outweigh the theories of physics every time.

Badger896

Bypass valve

It was the valve that bypasses the press red valve circuit. it was always off but until i could isolate the fill piping from the boiler there was really no way for me to tell that a valve thst was OFF was leaking past it!!! GO FIGURE

THX AGAIN EVERYONE

Tom_133

Thanks for the answer

For closing the thread and giving us the answer. It drives me crazy to read many, many posts and then no answer!!

Badger896

Pressure reducing valve

Yes pressure reducing valve not relief valve. sorry bout that. oh and yes the x tank static pressure at 12psi also..

SWEI

Let us know

how that 006 on the primary works out.