Radiant Floor Heating/stuck balancing valve


QUESTION: Hi Morgan,
I have an Eichler home in the Bay Area of California with about a 57 year-old Racon radiant floor system. It has 9 different loops that are balanced at a manifold that appears to be made of aluminum which has a balancing valve for each loop. The valve has a round 1.5 cm. "slug" held in place by a snap ring, and the slug has a slot which with the tip of a screwdriver allows one to open or shut the valve by a 90 degree rotation.
One of those valve's slugs is stuck and can't be rotated so I can't adjust it.  By feel of the temp of the steel pipe (7/16 i.d.) that goes into the valve it is in the closed position so that loop's room is not getting heated. I have been able to maintain the system through the years by finding and digging in the concrete for the leaks and patching to repair the pipe rot-out; and this is the only problem at the moment.
The 'slot' is no longer a slot having been gouged in my attempts to rotate it. I tried drilling a couple of small holes on either side of the slot into which I inserted the snap-ring plier tool but still can't budge the slug. I tried spaying WD-40 around the slug with its snap ring removed and still no rotation despite frequent applications.
If you have had experience with this sort of a locked up slug I would appreciate any ways I could try to regain use of the valve.
I thought of trying to drill a new hole in the slug to cause it to be permanently open but I would need to remove the entire manifold to get it off all the 9 tubes and that may cause evem more problems in getting it back together.
I thought about drilling out the slug entirely but then the issue of all the shavings getting into the manifold/water and then how to reseal the opening where the slug was inserted comes to mind.
I thought about heating the valve to see if that might free it up.
I thought about trying to remove the nut that holds the incoming steel pipe in place on the valve and then bending the pipe and trying to drill the slug passageway through that pipe opening but I suspect again that would probably damage the pipe (it is only 7" long above the floor) and result in a leaky re-connection of it.
So if you can comment on what I might try first I would be most appreciative. The system's main distribution pipe is providing water to the loop (I can feel it as it goes around the outer edge of the room) but no flow is occurring into the small diameter pipe loop of the room proper. So fixing the stuck valve would be very nice, as it is our master bedroom.
I volunteer at AllExperts in the Chrysler Repair category.

ANSWER: Hello Roland,

You will have to send me a picture.

Was you "steel" pipe failure from the inside or out?

This is embedded in the concrete?

Also send a pic of the boiler.

Thank you.

---------- FOLLOW-UP ----------

Racon Manifold
Racon Manifold  
QUESTION: Hi Morgan,
Attached is a photo of the left half of the return manifold which shows the balancing valves. The 2nd from the left is stuck and can't be moved.
The several earlier pipe failures I found and fixed usually involved steel pipe which was not fully imbedded in the concrete, but also when two separate pipes came in contact, etc. I have been successful in repairing the breaks by removing damaged pipe and jumping across the gap with automobile hose and clamps. The system has been tight for about a year now and I am hoping to figure out a way to open that specific loop where the balancing valve is stuck.
Thanks for any ideas you have as to what to try.

It appears that there is a retainer ring holding the valve in place. I would remove it and tap the valve or perhaps drill and use an easy out to turn it. You can always install a new manifold and adapt to the pipe going to the floor.

You could likely use a FERNOX treatment and this may loosen up the valve.

Best of luck.  

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Morgan M. Audetat


Radiant panel heating design, including floors and ceilings, European wall panels and snow melting for residential and light commercial buildings..............................................................-Master of Steam and Hot Water,City of Minneapolis....................................................--- Master Plumber, State of Minnesota...........


30 years..... Charter Board Member - Radiant Panel Association, former manufacturer of condensing boilers, former national distributor of radiant floor products, son and apprentice of mechanical & plumbing contractor. Current owner---www.BadgerRadiantDesigns.com---Minneapolis mechanical/plumbing contractor specializing in hydronic based, integrated HVAC systems. Radiant floor heating/cooling. Snow Melting. Condensing Boilers. Indirect water heaters. System design, consulting and technical training world-wide. Licensed contractor, designer, installer and consultant.

B.S. University WI 1981 CONTINUING EDUCATION: Viessmann Condensing boiler and Solar water heating certification 2010, N.D.S.U. Lead Worker RRP certification 2010, Knight condensing boiler certification 2009, Wrightsoft Manual J CAD certification 2009, RPA Designer & Installer Certification 2008, Nate Hydronic/Forced Air Certification 2008, Uponor/Wirsbo advanced design school certification 2007, Buderus Wall-hung certification 2007, Power Limited License (low voltage controls) 40 CE credits 2005, Basic Hydronic Certification IPEX & Northern Alberta Institute of Technology 1998, Charter Board Member - Radiant Panel Association 1994, Residential Off-Electric to Hydronic Conversion Heating School Canadian Hydronics Council 1994, B&G Little Red School House 1993, Rood Utilities (now Auburn Technical Institute) Oil Burner School 1993 ,Tekmar Controls residential and commercial 1993, Division Manager and Advanced Hydronic Seminar Instructor for the first Exclusively Hydronic Radiant Floor Distributor in the USA 1990, Hydronic Radiant Heating Association Workshop participant with Richard c. Bourne, PE spring 1988, Master Plumbing, Hydronic, Solar Course Red Rocks Community College 1987.

Awards and Honors
2009 System Showcase Award - Radiant Panel Association

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