Pumping away dilema

ishmael2k

both of the pics have been a great help.

I am considering getting a Spirovent and mounting the FilTrol as shown in eleft's pic.

This will require a substantial amount of re-piping but ought to be worth it.

The only thing that may preclude me from doing so would be a heat issue. I like the idea of keeping the expansion tank as cool as possible and with it mounted under the Spirovent it is going to be subjected to more heat transfer.

Maybe I'll add a second expansion tank under the Spirovent, would this be feasable? (I think my current one is borderline as to size anyway.)

Thanks again for all the info.

Rob

R Troughton

Got Dan's books yesterday and

read Pumping Away & How Come.

I have one question, on my system I am currently pumping into the bottom of the boiler with the expansion tank on the top. (I know, exactly opposite of what is recommended.) So I figured when I took the system down to install the new 8418 next week I'd either move the tank or the pump.

I am leaning towards moving the tank as it is the least amount of work and the one negative that I saw with pumping on the return should not affect my system. (ie overloading the relief valve) as my system runs at 12# cold and 20-22# fully heated.

Now my question, it also recommends pumping towards the make-up water feed inlet right? Well I am using an Amtrol Fil-Trol setup for my expansion tank.... This puts the feed line right at the expansion tank...

So, which would be better? Pump away from both the tank and the feed line or leave it pumping towards both?

One final, my feed valve is not left open, I just use it to purge the system when I do upgrades.

Any thoughts or suggestions would be appreciated, I really want to get this system finalized before cold weather slides in.

Thanks!
Rob

Steamhead

Rob, I assume

the Fill-Trol tank is mounted on an air separator, piped in the line going from the boiler to the system. This is the best setup for such a tank. Post a pic if you're not sure what you're looking at.

If this is the case, the circulator should be piped after the tank and air separator, pumping out toward the system.

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Tony_8

fill-trol

Since you're shutting off the fill anyway, it won't matter if it's on the inlet side of the circ. Moving the air eliminator to the return makes it harder to remove the air BEFORE it gets to the system (bbd,etc). The most pressure- balanced point of the system is at the expansion tank.

R Troughton

Actually,

the Fil-Trol is piped in the same place the overhead tank that was original to the system was piped.

This is off of a T that also houses the relief valve on the top of the boiler.

The only thing I can see that qualifies as an air seperator would be a B&G auto-vent in the first L on the supply side.

Ignore the wiring as it's temporary, waiting on the Aquastat to arrive.

The pump is located at the bottom of the picture on the return line.

Thanks

Rob

R Troughton

Not certain

if there is even an air seperator on the system.

Does a B&G auto vent qualify?

Thanks,

Rob

J.C.A._3

I don't see any !

With the air vent located there, there is a chance that when the pump comes on, it will unseat the float valve(pressure differential) and actually PULL air INTO the system.

Find a nice place to put an air scoop,Spirovent or the like, and feed into the boiler at that point. PONPC (point of no pressure change)is the ideal place to provide make up water. Circulator should be placed after the feed, pumping away from the expansion tank and ponpc. Chris

R Troughton

That's what I

was afraid of.

OK I am going to move the pump over to the other side of the boiler and install an air eliminator. It's going to take some thought as to where to add the eliminator though as space is limited...

This should eliminate the possiblity of pulling air into the system and will put the circulator after the expansion tank and the feed line.

Will take some pics of the finished product.. Won't be happening until next week though.

Thanks

Rob

Tom M.

What I would do

When a boiler has a 3/4" or 1/2" tapping right next to the supply tapping, it is usually designed to remove air. If you are already moving the pump to the supply side, that is a perfect location for the vent. If you follow that pipe straight up from the boiler, replace that top elbow with a tee and put a Spirotop on a 6 or 8" nipple. Also, I would replace that relief valve and put the new one in a vertical position. Sediment can build up over time in the horizontal pipe and if the relief valve ever opens, the sediment could keep it from reseating.

Now your circ is pumping away from the tank and feeder and your vent is in a location with high temp, low pressure and low velocity.

Tom M.

Steamhead

That's what I was going to suggest

but Tom beat me to it.

When you install the tee as Tom suggests to replace the elbow at the top of the riser that leads to the tank, install the tee with the run (the straight-thru portion) vertical, and the bull (the side opening) looking over to where the tank is. Then put your automatic vent in the top of the run, using a reducing bushing if needed.

Here's a boiler with this setup. You can see the vent (Hoffman #79, in the traditional dark green color) peeking up from behind the circulator, and the position of the tees is obvious. The tank is red and sits behind the circulator also.

This boiler is in my own house, and the air-removal works very well.

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R Troughton

OK!

I think I have it all now. (Well not really but close..)

Thanks for the advice!

Rob

R Troughton

Thanks,

the photo was an immense help as I was having some difficulty seeing the whole setup in my minds eye. (Sometimes very nearsighted...)

Rob

eleft(retired)_3

Spirovent

Unknown

I like this one the most

A picture is worth a thousand words.

Noel

J.C.A._3

The heat...

Will pass by the expansion tank! Water, like everything else, is lazy. It will be looking for the easiest way to get away from work. Pushing itself into the expansion tank will require more effort that traveling to the heat circut.
The only way it would make it easy, would be to have a leak in the tank, making the pressure LOWER there. With a charged bladder, that isn't going to happen.

One tank , sized appropriately will suffice. Chris

R Troughton

Didn't really

realize that, but I still think having the tank off to the side as it currently is will result in lower tank temperatures.

Plus once I re-pipe and if I add a Spirovent and add or move the tank there it will be quite near the supply line where it exits the boiler.

This is due to the amount of room I have to place the circulator and vent. Add to this that the exhaust piping is in the same area and the heat will definitly have a tendancy to build up in the tank.

Also when I size my current FilTrol it comes up borderline for the size boiler I have (165kbtu)and adding a 2nd ExTrol is a fairly cheap way to double my expansion size.

Thanks for the info! I learn more each day I am here.

Rob

Unknown

If you have two tank locations

you don't have control of the point of no pressure change. A lot depends on where the two are located, and what the precharge is on each.

I wouldn't do it.

The manufacturer allows using the tank on the boiler outlet. That is good enough for me.

Noel

R Troughton

Hmmm never

thought of that...

Ok, I guess I'll stick with one tank.

Thanks!

Rob

R Troughton

She's now pumping

away!

Spent a good part of the evening re-routing pipes, moving the pump, adding valves and a LWCO (MM Guard Dog)to my system.

It is now officially pumping away from the boiler, I still need to find a SpiroTop vent for it. They are not available at the place I get my plumbing supplies from. (Fairly large wholesaler, I was kind of surprised as they have had everything else I have wanted.)Will do some phone research tomorrow.

I'll post a pic once I get the wiring completed so you guys can tell me if I messed something up.

Thanks for all the help so far!

Rob

frank p

end results worth the pain

I read the book and promptly went thru the trouble of moving my circulator from down on the return side up to the outlet side directly after my tank/filler/seperator setup. (The tank setup was already on the outlet side.) Once all the air was out, I had to put my ear down close just to hear the circulator! I thought the humming noise that it made all through the last two heating seasons was normal! The minor water-whooshing noise I had in the baseboard-heated section of the house is also gone! I may have had some air issues the whole time and this took care of it. Ditching the 'factory' setup and switching to pumping away was well worth the trouble. The system has never been so quiet!

R Troughton

Well it's a work

in progress but I now have the SpiroTop, and new relief valve installed. I also have the new Aquastat installed but not wired. (Not running the system right now, it's been in the 70's here all week)

I am about done, need to install and wire the new thermostats.

I agree it is all going to be worth the work. The system is a lot safer and more efficient than before. Won't know about the noise level until I have had a chance to run it for awhile but it never was a loud system.

Thanks again guys for all the help.

Rob