circulator does not stop water flow?

scratchinghead

so we remodeled our bathroom, and as part of the remodel we moved the baseboard heating element several feet to a different section of the room. The old baseboard was fed with 1/2 inch copper for some reason so we brought this up to 3/4 copper. all of the other elements on this heating zone are big cast iron radiators. The elements are all in parallel (each element has a direct connection to the supply and return pipes going to the boiler.



my problem is that since the remodel (nothing else was changed on the heating pipes) when a different zone calls for heat, this zone heats up. when zone 2 for example kicks on, it seems like water is being pulled backwards through the circulator for zone 1. my circulators are on the supply side, and when this problem happens zone 1's return pipes heat up quickly. My quick solution to this problem is to shut off one of the valves on zone 1. If i shut off the valve at the return side of the boiler for this zone or the valve by the circulator then this zone does not heat up when the other zones turn on.



The circulator for zone 1 (problem zone) seems to function correctly when that zone calls for heat. If it calls for heat, it turns on and water moves through it and the elements all heat up. I do know that this circulator is not turning on when the other zones request heat. this was my first thought and i disconnected the power to that circulator to verify that it is not turning on.



so i have a few questions,



1: should water ever be able to go backwards through the circulator when it is not on?

2: could my problem be the increase in the diamaeter of the pipe going to the baseboard unit? Should i cut the 3/4 pipe and put in a 1/2 pipe (maybe with a shut off valve to test it)?

3: should i just replace the circulator?



thanks for the help

Mark Eatherton

No checky, back flowey...

Any time you have more than one pump piped in parallel, you MUST have check valves at the discharge of he pump, otherwise water will flow backwards through the OFF circulator.



Some pumps have a check valve built into them. Some don't, and to the untrained eye, are impossible to tell.



Pipe size wouldn't have stopped this problem. If these pumps were existing, and there is a check on the outlet, it could have gotten fouled with rust, or solder balls.



There could be other problems, but I suspect the missing check first.



Does the boiler also do DHW?



Got pictures???







ME

scratchinghead

IFC circulator

Mark, i have a buderus lgano G215 with three taco cartridge circulators model 007-F5-7IFC



 i did some web searches on the circulator and from what i can tell the IFC stands for integrated flow check. would you say that some how rust or solder is stuck in the unit?



if i were to replace it, would i be able to replace just the cartridge or should i replace the entire unit? The following link says that the IFC is serviceable... i am not sure if that means replaceable or if i can open it up and look for a blockage?



http://www.taco-hvac.com/news.html?News=21





i can take pictures of the set up later on if it will help, but it sounds like the problem is with the circulator

Mark Eatherton

Those flow checks work GREAT for stopping back flow....

but don't have a strong enough springs to stop forward flow.



A picture would be very helpful.



And, they do get fouled with rust, solder balls etc.



It can be removed, but may not be necessary. It may require a repiping of the system in order to correct the current situation.



Show us what ya got.



ME

scratchinghead

picture

so the three circulators are on the supply side. you can see where the zones return. zone 1 is to heat up the DHW. zones 2,3 are for heat in the house. 



when zones 1 or 3 turn on and the valves for zone 2 are open, the return pipe for zone 2 heats up. the supply pipes heat up over time if zones 1 or 3 are on for long enough. if either valve on zone 2 is closed, the pipes do not heat up.

Matthew Grallert

A little crud

A little crud can move a long way.  My bet, and I've had it happen, is a piece, could be a very small piece of crud has found its way to the internal flow check inside the pump.  Someone should be able to find this easy enough.  Make sure the space is well lit.

Peace

Matthew

scratchinghead

how to clean

mark,

so to find out if the circulator has crud in it. can i just remove the four bolts and take the cover off? If i take the cover off, will it be obvious where to look for the crud? will the i need to take multiple pieces apart?



Thanks

ChasMan

IFC's

Check out the manufacturers literature.

http://www.taco-hvac.com/uploads/FileLibrary/102-135.pdf

Taco has great literature.

Mark Eatherton

Nice install...

THe pumps are of the correct design and are installed in an ideal situation. Fortunately, the installer did a good job and gave you individual isolation AND the ability to purge the pump.



Make sure you have all the necessary repari/replacement parts before you dive int othis task,and if you are not comfortable working with water, and electricity, call the original installer back for service.



ME

Mark Eatherton

The reason this is doing this...

I got to thinking about this scenario. First off, you could reduce the energy being consumed by putting one circulator in place, adn using zone valves to control flow. Best recommendation would be to use a variable speed, constant pressure pump from any of the manufacturers offering it.



But the reason it is doing it, is because the return piping is undersized. Looks like they reduced it to 1-1/4" on the return. Water, being like my ex brother in law (wet, lazy and stupid) wants to follow the path of least resistance. If this were piped correctly (LARGE fat headers as Siggy says) the water would naturally follow the path of least resistance, back to the heat source.



Us Americans have SO much to learn....



ME

scratchinghead

metal piece

So i took the circulator apart to check if there was something blocking the IFC. after disconnecting the unit, i stuck my finger inside to check the IFC. I pushed up, and the green plastic pushed up... so if there was water pressure, water should be flowing through...



however, there was a metal piece that fell out after i stuck my finger in there. see the picture, it is a rectangle, but it is either broken, or all four ends were never connected. is there supposed to be a metal piece in the IFC? I then tried to pull the IFC out with needle nose pliers like the directions say... the unit did not want to come out so instead of yanking on it, i just put it back together to see if that metal piece was the reason why the IFC was always open.



I turned the boiler back on, and turned on the other zones and the trouble zone did not heat up. I waited 15 minutes, and the zone never heated up.  that seems good... so i turn the trouble zone on, and the circulator kicks on but the zone never heats up.



It now appears the the IFC is stuck shut!



I took the unit apart a second time to verify that the motor was working (the impeller spins), that the IFC still works if i poke it with my finger (it does), and to see if i could get the IFC out (i could not).



does anyone know if the IFC has any metal pieces other than the spring that closes the IFC? It looks like it should function just based on water pressure... the information on taco's website does not seem to show it in great detail. has anyone ever had trouble removing these from the circulator? I did not want to cause any damage so i did not pull as hard as i could.



is there something else that can be going on? I bled the radiators to see if there was air in the system, but no air came out only water from all of the radiators. I ordered another circulator so if i can not get it working i will replace the unit next week.

icesailor

Water Flow:

Mark (ME),

I know you guys love those IFC circulators with a passion but if a "regular" flow check had been used instead of the IFC circulator, the heavier weight of the flow check disk would probably stop the circulation. And be easier to trouble shoot.

And then there is the question about moving baseboard radiation that is mixed with radiators. Is the zone piped as a one pipe system with Mono-Flows? Someone goofed. Possibly.

My REAL complaint with IFC circulators is that there is no way of knowing if the check is open or closed. I drain a lot of houses for the winter that have hydronic heat. Be as it may, IFC's are not on my radar for looking at things to open. I make sure that any flow check is open. If I don't, that main will have splits and breaks. And if you do realize they are there, how do you get them open?

More over engineering at work.

tim smith

RE: flow in off zone

Looking at your piping and your description of problem. I am pretty sure you are getting ghost flow up the return to the off zone. Either a thermal trap on the return or flow check is usually what we have to do to fix this. Pretty common in old large piping systems that have been converted. Good luck. Tim

tim smith

RE: flow in off zone

Looking at your piping and your description of problem. I am pretty sure you are getting ghost flow up the return to the off zone. Either a thermal trap on the return or flow check is usually what we have to do to fix this. Pretty common in old large piping systems that have been converted. Good luck. Tim

Mark Eatherton

You have to force purge the circuit...

Just turning the water back on to the circulator doesn't guarantee its going to have enough water to allow it to do its thang.



On the return main there is a ball vale with a drain cock. Close that main ball valve, and hook a hose to the drain cock. Then close all but the bad zone, and turn open the drain cock on the return. Run it for a few minutes to insure that the pump is wetted, and if everything is OK, it should take off on its own. If not, replace the pumps check assembly. These things get grown in after while and require some angling and dangling and twisting and rocking and pulling to get them out, but it should eventually come out. No one said this was going to be easy :-)



TO Icesailor, I have had situations before, prior to the introduction of IFC's, whereby we had used SWING checks to stop thermal migration, and they DON'T hold back gravity circulation. Had to replace them with a good strong SPRING check.



Personally, I am not a big fan of any of the pumps with integral checks. Too many problems similar to yours.



They do save time on initial installation labor, but that will probably be a wash when you're done messing around with fouled checks.



I am not familiar enough with the Taco product line to say whether the piece you found is from the check or something else. Wouldn't be the first time a UMO (Unidentified Metal Object) has been found floating around in a system...



ME

icesailor

Flow checks:

ME,

The old dead wet heads never used swing checks. They/we always used flow checks like a B&G SA-1 1/4" or Taco and many others that are no longer made. Because mains were usually 1 1/4" on one pipe mono-flow systems, I never saw any problems. These checks had a flat disk that rose vertically and they were shaped like a Tee so you usually piped into the bottom and out the end. The rise in temperature couldn't push up the disk but the circulator could.

The old guys said to not use 1" or 3/4" flow checks for some undefined reason. That if you were running a 1" main, to run a 1 1/4" supply and reduce at the outlet of the flow check. Perhaps this is because of the lighter checks on smaller flow control valves.

I personally think that some of these problems are being caused by over sized circulators causing all kinds of pressure differentials in the system.

I've never personally seen a smaller check leak by but then, I don't under size my piping and correct the problem by using high head, high flow circulators. It will cause a lot of cavitation and the resultant problems.

Just my personal feeling and opinion.

Mark Eatherton

Understood...

And I agree whole heartedly.



The problem is the dead men took most of their knowledge to the grave with them, and the easy way to make sure the technicians never get a phone call is to oversize the high head circulators...



You probably already know the answer to this next question. Friday night, 5:00 PM, and Mrs Smiths circulator dies. Do you know what the right replacement pump is? Whatever you have on the truck that will fit between the flanges ;-) Temporarily of course.



BTW, Webstones makes a real neat isolation ball valve flange assembly with a side drain cock that allows you to drain the downstream part of the system for winterization. And I agree, inexperienced winterizers who don't know that these things hold water up get into more trouble than they should.



I think we see aye to aye :-)



ME

icesailor

Dead Wetheads:

Well, they did leave a lot of their info behind. But it behooves us to go out and find the info. A lot of those old guys had taken the IBR heat loss courses. Figuring the heat loss was a piece of cake. When you got into the yellow #250 piping book, you really learned the stuff. I unfortnnately could never go to the courses so I bought the books/course and learned it on my own. GAMA/IBR did away with the yellow book for a combined white one #250 but I know it leaves some stuff out. I had the yellow book and loaned it to someone who never returned it. Then, there is a book that came from B&G and had that stuff about primary/secondary piping and the guy who figured it out to solve a problem mistake in piping at Notre Dame. Taco uses this bok too. 

My comment to over engineered and designed piping. "Don't try to re-write the laws of physics.

Ever notice that there wasn't much of a problem with cavitation and air problems when circulators were turning at 1725 RPM's but now that they turn up at 3000 or more, you have a problem. High tip speed.  

scratchinghead

thanks for the advice

I wanted to thank you for your help. I was going to try to force purge the system, but decided to shake the pipes again just to see if there was an air pocket just above the circulator.  After a few hard shakes, i turned the system back on and the circulator is working as it should.