Pumping away

Uni R_2

I really think that it is an air issue. If you have enough static pressure and your circ is up to snuff then there should be some heat going through there. Even a diveter branch that has a closed valve will still give off a bit of heat as long as it isn't airbound just from gravity flows within the pipes, even downward flowing branches. I think it really takes an air pocket to stop the heat completely.

Will Merryman

Pumping away now diverter problem

Hello all,I inquired on this forum about adding a zone and was instructed to "pump away". My boiler was shipped many years ago "pumping to". The change over went smooth except for the expansion tank issue that I also inquired about.


Then I experienced a noise problem from the old steel tank.After posting here I eliminated it for a modern diaphragm one.Cured the noise problem.Also I purchased the book "Pumping Away" It was a fantastic read for me. I set up the tank just like in the book with air scoop above and feed water piped in above tank. That went smooth also.

Now comes the tough part. I have a one pipe diverter t set up in a continuos loop around perimeter of basement, 1 1/4". I have had a problem getting 1 baseboard to heat last year and had been able to work thru it. I figured that when I changed over to pumping away that baseboard would no longer be a problem.


This baseboard will not heat now.No air at all. Dan says in his book that air is not the problem. I lengthened the space between t's. No help. I just shortened the baseboard from 12' to 102"(center to center on el's) with the T's being 93" apart from center to center of tubing. Still no heat. I moved the diverter T in line with the return T as it was formerly just after a 90.Now its a close nipple before 90. They are Taco cast iron with arrow in correct direction.


I just checked out Taco site on T's and they have a schematic for using 2 Diverter T's together. In Dans book he details that configuration for radiators below heating loop.
Would this option work for baseboard above ? Also I get the feeling the 90 deg. elbow has something to do with this problem ( added turbulence ? ). I can't extend it any more as the wall is close by.Would diverter T be better after elbow but further away than before ?


When I bleed out the air from my changes I have to shut off the flow on the standard T.When I turn on boiler again and circ. comes on the return gets hot and supply doesn't. Its like both sides are pushing against each other.I turn off return side and hot water comes tru from diverter no air but doesn't stay circulating after shutting of vent.There are 3 other baseboards after this one with one on the second floor that all heat great.There are 3 before also and they are fine.


Sorry about the long post but am confused as to why when pumping to versus away this problem would be unsolvable in this one baseboard.Is the only solution a dedicated circulator ? can it be wired in tandem with the main one as everything at this point is controlled from one thermostat?Is it possible the T is worn out or somehow defective ? I appreciate all the advice I have recvd. here and extend my thanks.

Will

Uni R_2

Level?

Is that baseboard level? Could it be possible that it is airbound but not where the bleeder is located? That's a strange one!

Unknown

Sometimes I have found a kind of ballvalve on one end of the baseboard. The kind where you need a flat head screwdriver to open. Are there any of those on the baseboard loop that may be clogged? All your pipe work may have clogged something in that loop.

At this point I would be investigating a restriction in the pipe causing your problem.





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Unknown

Will...........

pumping away is definately the best way you could have gone! Now, this one "problem baseboard", is it the longest in the group in the circut? As Dan says, usually when below the main 2 diverter tees are used, usually only 1 above, but there are exceptions to that rule. You have to have the flow from the circ, in the first place in order for the tees to divert. The length of the rad can also add a resistance-factor this diverted water has to push through.I bet the other 3 BB after this one is shorter, and the one upstairs, well gravity helps on that one. Give us a few more details like the entire loop length, the circ. you have, the number of diverter tees on this loop and the indiviual rad lengths and that should get us off to a better start, OK?

Will Merryman

Uni R

I will check it again for level.Fin tube sets on brkts. where it belongs and house isn't that far off. (LOL) When bleeding I learned last year to bounce the entire length of fin tube to produce some more air not normally bled out. That trick worked last year but not now.Also a new taco 007 circulator so that shouldn't be an issue. Both second floor rooms get plenty of heat.I also tried throttling the return ball valve to try to achieve continued flow by limiting the flow up the return.
Will

Will Merryman

Dave

I will measure everything tommorrow and repost Wed. evening. Thanks.
Will

Will Merryman

Norm

I have went so far as to remove the whole length of fin tube and sight down it for restrictions, don't laugh just grasping for straws. Regular el at supply (diverter side) and bleeder el on return. No big solder lumps. New ball valves below and new pex for the connection from T,s to baseboard via sweat male adapters.I am ready to go pick up some new bb but that seems like throwing parts at the problem hoping something will work.Thanks for your input.

Unknown

Did you say,

You had pex adapters sweated to the copper? They will add alot of resistance to the diverted circut!

Unknown

Why is that?
I was lead to believe that pex offered less resistance than copper.

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Unknown

Will, this post,

will still be here, just add to this.

Tony_23

Issues

I always use two tees, it insures flow thru the branches.

The ell you removed gave you resistance between the tees that you needed. Put it back, if possible.

The pex has a different ID, probably smaller. Pex has less resistance to flow in a whole system approach because of the lack of ells needed for turns. In this case, you've restricted the branch by installing an "orifice".

TK03

Air

Everyone has offered great information.I would like to add one. If you use pex or not I have seen air pockets in either supply or return which will give you water at the bleeder on the heat emmiter.Maybe house settles, something drops on the pipe putting a little downward belly in the piping and the water will push air out one of the pipes but not the other. I have installed a purge set-up in the return pipe and resolved the problem. Just a thought.

Unknown

Certainly worth considering,,,,,,,,

Heatman, but sounds like an awful lot of "fooling-around" to get not much more than "gravity" flow though the rad. If you have the flow along the main, and a very small resistance in the branch between the tees, it`ll move, and carry any amount of air out with-it. I`ve never been a big fan of pex fittings in Mono-Flo systems as the fittings themselves are very restrictive, just sight down one, like Tony says, it`s like an "orifice" in the branch. He(Will), likely got told otherwise from a "big-box-store" who sells the stuff!

Unknown

another angle to consider

Though I agree completely that the pex, and the lack of a second tee are contributing factors, I also think that you might figure the head for the whole loop, adding the Tee's resistance (typically 10' of pipe each) in, and see if that 007 moves enough GPMs to do the job.

Noel

Will Merryman

Pumping away now diverter problem

Well I have cured the problem thanks to all the suggestions. It turns out I checked for level previously by laying level on the top of the enclosure.I laid 4'level on the fin tube.There was a dip of 1/4" at the joint between tubes. Upon closer examination all the mounting brkts. weren't installed. I think when the joint was soldered the heat caused the dip.


I bled many gallons from that baseboard from both sides shutting off ball valves one at a time.I charged that length with bleeder open also.Everytime I bled I got air. But not all of it.I cut some small blocks and shims and had to force fit to straighten out the tube.Turned up tstat and waited for circulation.Opened bleeder and got water. I then pushed down very lightly on fin tube causing a slight deflection a different technique than my bouncing.I got a small fart for lack of a better description. Pressed down again in a different spot and got some more air. Guess what came next.
HEAT !!!!!!!!!!!!!Yahoooooo.


Well now that I butchered up the BB I have an excuse to go buy new.It will be installed with the full complement of brkts. and will check for level on tube and not the enclosure.


Near as I can tell the air bubbles must have laid low while the water went over top while bleeding only to rise up when bleeder was closed. makes me wonder if there is a vaccuum bleeding apparatus for heating.I use one for automotive work on every antifreeze refill. Never have an air bound situation and it checks for leaks prior to refill.


Again my thanks to all who weighed in on my issue. You are all a great bunch who take pride in your trade as well as share your experience. I read a bunch of posts every night just wanting to pick up some knowledge and enjoy the banter concerning brands and methods of application, and to see the pics of your installs.

[Deleted User]

Tee's for two...

You can put a diverter and a monoflow on an up feed convector, but unless the convector is a high pressure drop unit, it is NOT typically necessary.

You have mother nature working IN your favor with an upfeed convector (hot fluids rise, cold fluids settle). I concur with my fellow associates, it is either an air problem or some other restriction. If you have enough slack in the piping to the point that you can lift the fin tube up, so the coin vent becomes the high spot, you might get some more air. By the way, never try bleeding with the pump running.

If worse comes to worst, try cutting a drain cock in underneath the cover of the BB, and put isolation on both the supply and return, and power purge that sucker, closing one valve and purging through the drain, then opening the other one, closing the other one and again power purging.

This stuff is not rocket science, but it is amazing what a little air can do to spoil the whole shebang...

ME