Where can I add a scoop and air vent
Where would be the best place to add a Taco vent and airscoop with the current setup
Comments
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It's pretty tight. Unless you want to do a near boiler re-pipe.
What type of heat emitters do you have? If column radiators, just bleed them at the rads0 -
I have radiators. It helps, but sometimes I have to do a drain and refill, and bleed to get all of the air out. Was hoping a vent and scoop could help. I don't mind doing a little repiping. What would you suggest?
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Why would you have to drain and fill?
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if im seeing it correctly there is a pump on the supply and returns?
If that horizontal pipe between the pump and union is a supply, adding a purger there would be idea
An issue with those old large diameter iron pipe systems is the flow velocity can be low, below 2 feet per second and the air doesn't move along with the water well.
Use a good micro bubble type purger
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
if oo
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
For some reason that has been the only way that I can force all of the air out and eliminate noise. The system probably needs replacing, just trying to hopefully get it along for another season.
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There are three zones, a pump for each. I'll have to check when I get home to confirm if that horizontal pipe is supply or return.
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Air and noise are most likely from not following best piping practices, specifically pumping away from the expansion tank instead of into it.
Just adding an air vent, especially in the wrong spot will only make it worse.
A proper repipe would solve all your problems, and barring any leaks in the system, and probably the last time you’ll have to bleed and purge.
3 story house?1 -
@HydronicMike Yes, It's a 3 story house; basement, main floor, and attic. Basement and attic has baseboard radiators and the main floor has radiators.
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If I’m looking at your pumps correctly, they’re both pumping downward, perhaps into expansion tank, and it’s always best to pump upward, that’s where your entrained air wants to go. Also as Dan Holohan,’s book “Pumping Away” recommends pumping away from the expansion tank, point of no pressure change. Repiping might be a good place to start. It will certainly help with some of your issues. A Taco 409 vent will help expel air, but start with aligning your flow with how air wants to move in the system.
Joe Mattiello
N. E. Regional Manger, Commercial Products
Taco Comfort Solutions1 -
I bet this house had a hand fed gravity hot water coal boiler in it at one time.
You have three circulators, I guess I would invest a few automatic air bleeders ball valves and fittings for the top floor radiators to get rid of the air for now and save money to convert the rats nest to a one circulator system with simple zone valves.
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Where are you going to get 1-1/4" or 1-1/2" zone valves for that old radiator zone
Not all the pipes are visible in this photo:
There is a 1-1/2" supply that exits the top of the boiler on the side where the Aquastat relay is mounted. That Aquastat relay is actually mounted on a 1-1/2" x 3/4" x 1-1/2" Tee fitting. The Red arrow indicates the vertical 1-1/2 or 1-1/4 vertical supply riser. The three returns are also designed poorly, but it has worked for years so no need to change it out now. (if it ain't broke don't fix it). Just when the replacement boiler shows up, have someone that understands proper piping practices prepare the piping properly! Say that 10 times fast.
The best spot to place a Discal would be on that riser. indicated in the drawing and the photo. You will need a repipe of that vertical so you can add a short horizontal for the air separator. That will be a bandaid until you do a complete repipe with the new boiler. The proper fix is to start from the boiler and put all the circulators on the supply side after the Discal where you mount the extrol tank under it. Get the book .
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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I am not disagreeing with you Ed, I thought the $10 autovents with ball valves mounted on the radiators on the top floor would be a fast fix for the rats nest he has there. Even feeding the system with a single circulator fed open to air gravity flow tank would be an improvement and would provide slow even heat.
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The problem is circulators pumping into the ponpc. This is dropping pressure, probably sub zero into the top of the system. Adding auto vents at the highest part of the system will introduce more air into the system not expel it.
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Sorry for the late response. Thank you very much for your explanation and the drawing on where to put the Discal air separator! I'll be sure to ensure that when I have a new boiler installed, the installer is experience with residential boilers and piping. I'll also review the book that you recommended.
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@EdTheHeaterMan Here's a better photo of the right side of the boiler. Can I replace the union with an dielectric one and add a 1 inch copper pipe for the Discal? Any suggestions on which air separator to buy?
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the 1” threaded Discal vertical has a 14Cv. So it can handle 140,000 or so
551706A is the 1” FIP
With the union there it would be a simple install if the piping is 1-1/4, use a couple bell reducers
Or get a 1” FIP pump flange and a bushing for the union
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Agree with @hot_rod on using the vertical Discal however if the pipe nipple that is horizontal in your photo is 8" or longer, then the 1-1/4" or 1-1/2" Discal should fit just fine there.
And there is no need to use a Dielectric union there. It is not an open system so the dissimilar metal thing is not that big of an issue. There are already several locations where the pipes transition from steel/iron to copper on your system. I have done that for 40 years and no houses have been destroyed as a result of that practice.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
@hot_rod @EdTheHeaterMan Thank you both for the detailed information! I'm not going to be able to get the Discal and do the work for at least a couple of weeks. I'll let you know how it goes. Best!
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Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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@EdTheHeaterMan I'm not sure. My expansion tank is fine, so it will be back to the drawing board.
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After looking at the pipe you indicated for installing the Discal, I made a mistake. That is a return pipe and that will be the wrong place top install the Discal. You want it on the supply side as shown in this illustration
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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@EdTheHeaterMan I'm sorry for highlighting the incorrect pipe. Thanks for the correction. I don't think that horizontal pipe over the supply is 8" long. I'll have to measure it tonight when i get home. Also, it's really strange how the supply is branched to the radiators. It's hard to see in this picture. I may have to take multiple pictures and label them A, B, C etc. so that the routing is displayed. I'll try and get pictures tonight and label and upload them when I return to work tomorrow. Sorry for the late responses. I've been posting using the computer from work, because my laptop is having issues.
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I think the supply pipe is the one the aquastat is mounted in. There are 3 pumps all on the returns from what I see.
I would disconnect the supply at the aquastat and elbow it back to the wall then rise up and elbow back into the supply. That will give you more room at the top for a longer horizontal pipe to put the air eliminator in. Use copper
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Looking at the pipe it may only be a 7.5" or 7" pipe nipple. but that would have been cut and threaded on site, because after 6" the store bought pipe sizes climb by full inches and the odd numbers were ofter not in stock Close thru 6" were every 1/2" so with 1-1/4 and 1-1/2 pipe nipples you can could get 4", 4.5", 5", 5.5", and 6". after that you could ger 8", 10", 12" and so on.
Regardless of the size of the actual pipe nipple, there may be as much as 1/2" of threads inside the fitting on each end. Looking at the chart Provided by Bob HotRod Rhor the Discal is just shy of 5 inches. so adding a close nipple to both sides would be about the same as a 7.5" nipple. I think you can make it fit with a little bit of adjusting of the fittings.
Another idea is to swap out the iron for copper and you have more wiggle room with a slip 45° or other adjusting.
And not to Dis' on Discal, the Sparco Vent by Resideo (Honeywell) may be even shorter. Not as food a product but will do the job for you.
Edward Young Retired
After you make that expensive repair and you still have the same problem, What will you check next?
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Speaking as a lay person,
I think you should seriously look at installing a heavy duty air vent from Mcmaster-Carr in the unused tapping in the steam chest for the mess of plumbing you have as that would be the simplest thing to do.
The bottom female thread one inch ductile iron air vent is $138.72 plus tax and freight
It has a female threaded vent port to allow you to vent any air away from the boiler with 1/2 piping
Part number 48045K71
Part number 48045K72 has a 3/4 inch bottom female tapping with a 1/2 vent port.
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The use of the words "steam chest" is a common reference for hot water boilers as many of them can be used for making steam heat or hot water/hydronic heat.
You should look at the vents I uploaded as you can still use them if desired.
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