Air Scoop/HyVent Leaking

MikeySW · October 30

Hello all,

I have a radiant floor system off a natural gas boiler that was installed in 2006. I am the third owner of the home and have 'managed' this system since 2019. I have had a very, very hard time finding a competent company that knows anything about these systems. The company that installed it does not do so any longer or service them.

I have a split system. One manifold that serves the zones in the basement, and another that serves the main floor of the house located in the garage. In the basement there is a Taco VorTech VRTX125-3 air scoop with a factory installed HyVent 419-1 on top.

About a month ago this combo starting leaking from the vent cap. Not a little. A lot. I shut off the isolation valves, and then shut off the boiler. Started things back up about 15 minutes later and it stopped leaking.

This little dance continued for a few more nights (I have a remote water sensor tied into my security system that I put below the scoop/vent) and I called the one company that sort of seems like they know what they are doing? Long story short, he opened up the HyVent, cleaned it out, and said that should do it. It did not. He said I probably need a new vent.

Okay, I ordered one from Supply House. Swapped out the cap and the internals of the existing one because of the design of the air scoop (see picture), and I'm thinking we are done here. That was 2 days ago and we are not done here. Started leaking again last night. This seems to be a pattern too. I think this is when the first of the zones upstairs are calling for heat the boiler comes on.

Anyway, does anyone know why this air scoop/air vent combo is now trying to identify as a water feature??

My system pressures seems normal (15-20 psi when hot). My temps are in the 120-125 range. Both manifold pressure and temp gauges appear to be working and normal. Gauges at the boiler all reading normal. My expansion tank bladder seems fine (water on top, air on bottom when doing the knuckle test).

I'm going to call the company that I use to come back for yet another 'service call', but I have very low confidence at this point on their diagnostic abilities.

Thanks for any help or advice. I've posted some pics. If anyone wants any other views or closer pics of components, etc. just let me know.

Alan (California Radiant) Forbes · October 30

Those HyVents are notorious leakers and your guy did the right thing. Seems as though you have a lot of debris in your system that fouls the valve which then leaks.

In a perfect world, you should install a DirtMag to remove the debris. For the time being, screw down the cap on the Schrader valve to stop the leak and only open it up once or twice a year to vent air and then close it again.

That looks like a Danfoss Zone Control panel.

Twenty years is pretty good for your Munchkin to still be working. You must clean the heat exchanger regularly? I'd be looking to replace it next summer to be on the safe side, especially with a radiant system. It doesn't look like an easy job - very little room.

MikeySW · October 30

Alan,

Yes, this is such a small space with a 80 gallon indirect water heater off to the one side, water softener right up front with salt tank, incoming well water expansion tank, etc. It's a zoo. This maintenance room could be twice the size and it's still too small.

Okay, so even though the HyVent is new it's probably clogged already? I'll look into the DirtMag.

Thanks for your comments. Much appreciated.

hot_rod · November 1

you should be able to remove just the top of the float vent. Inside a rubber seal and a needle type valve, easy to clean.

Although you may need to drains down or isolate it somehow.

MikeySW · November 2

Bob,

Thanks very much for your input. Yes, I did take the original vent apart and clean it. I left the vent cap open about a half a turn and I thought the issue was resolved. A couple of days went by and water started streaming out of the vent cap again. To be clear, water is pouring out. Not a little, a lot.

I then ordered a replacement HyVent entirely (Model 419-1). I swapped out the old float assembly for the new one and also swapped out the cap, essentially giving me a 'new' component within the old housing of the VenTech air scoop body.

Again, I left the vent cap open a half turn to allow air to escape and I thought all was well. Same thing after I cleaned it, a couple of days later water is steaming out of the vent cap.

So, not sure what to make of this phenomenon. It's not as if the vent is spurting water in the process of removing some micro-bubbles due to heating. It's somehow allowing water past the float and out the vent in a way that makes me believe something else is wrong? If trapped air at the top of the vent is supposed to allow the float to travel downward and open the valve, what is the scenario where the opposite occurs?

Is the float being pushed up by water and then there is nothing to close the top vent and instead of air being released water comes out? I'm not following what is supposed to close the vent when the water level increases (for whatever reason…this is an unknown since the vent is at the highest point in the system in this setup).

Anyway, I can open it up and clean it yet again, but if that's how I have to proceed (cleaning this thing every couple of days) that doesn't seem like a tenable solution.

Again, thanks for your comments.

Michael

hot_rod · November 2

I assume the vent was leak free at some point since 2019?

Munchkins typically had high head circulators. In some cases the float can be pulled down on the inlet side of a circ IF the expansion tank is mis placed. It looks like the tank is connected to the bottom of the air purger? If so it should not see a negative pressure that allows the float to drop.

Push in the valve under the cap on the expansion tank, air should come out. If water comes out the tank is waterlogged and could be

We have a band aid for that condition at Caleffi, a check valve cap for the vent, air comes out, but air cannot be pulled in allowing the float to drop. 5621 anti-suction cap. It goes under the normal cap.

As Allan mentioned it does look like a Danfoss or Wirsbo pre-fabed cabinet? Or a copy of them. If so the components are in the correct place.

Some arounds from Taco or Caleffi :) you can get this thread adapter to NPT that allows you to run a tube down out of harms way for when it leaks. Not the best fix!

Of this hydroscopic cap catches any water that gets by the float valve, a second shut off function.

And the hydroscopic cap could go on the check valve, for 3 levels of protection.

If the system is air free, as it should be, the cap could be closed off. If air is a re-occuring problem, another problem exists.

MikeySW · November 2

Bob,

Yes, since I inherited this system I have not had this phenomenon occur before. I frankly never touched that VenTech scoop or the HyVent on it ever. I'm assuming it was open and air would vent as needed, but I honestly never checked it. It could have been closed the entire time and the gasket on the cap finally failed and thus the leak? Not sure.

As far as the expansion tank placement, it was replaced when we first moved in back in February 2020. The tech noticed it was water logged. He replaced the tank in the exact same location as existing. I'll attach a pic of how that line goes into the system, but again, all has been functioning as intended since then. The tank appears to be good, or should I say the tank bladder. If I push the valve on the bottom, air does come out so I think this is not an issue.

As far as any other air separators or vents on the system, there is one on the upstairs supply that I occasionally crack (rarely does any air come out..just water..I keep it closed). The one in question also has never had air come out if I were to open in manually. So, I don't think I have any issues with air getting in the system.

Would I be okay to just leave all separators/vents manually closed and then occasionally open them to bleed any air that may have accumulated? At this point, I don't see any other option for explaining the water flow out of that vent. The tech I talked to last said he was not sure either.

That's an interesting workaround with that copper tubing. Not sure I could pull that off unless I changed out the scoop entirely and switched to another vent like the one you showed.

Thanks again,

Michael

MikeySW · November 2

Here are a few more pics. Also, what is this horizontal green device?? Do I need to change anything on it? Appears to be set to 10-ish? Pressure? Anyway…

hot_rod · November 2

yes, if you do ot have air issues , noise or lack of heat, close all the vent caps. Maybe the cap on that air purger has always been closed?

The green valve is the system fill valve, a pressure reducing valve, basically

Usually there is a backflow valve next to it to prevent boiler water from backing into the water system

MikeySW · November 2

Yes, I think you're right. That vent cap was probably always closed and the gasket gave after 20 years and started to leak. I then opened it thinking that was the correct thing to do.

I have heat. I sometimes hear popping in this one bedroom floor, but it has always done that. I've told the various techs about it, had that loop and the entire first floor zones purged with a transfer pump to move any blockages along in the manifold, so I don't think it's trapped air/debris. Using a thermal camera I can see all the loops heat and cool appropriately as the actuators open/close and the circulating pumps come on and off.

I'll keep everything closed and purge air from vents manually periodically and hope that works for now.

Thanks.

hot_rod · November 2

A popping sound is often just the floor or plates expanding as they warm

Most all materials tend to expand when heated, usually it is the flooring material trying to move making the noise

MikeySW · 1:16AM

That makes perfect sense. I have large tiles as my floor substrate so I'm sure they move as they warm up.

That's good info Bob. Thanks again for all the information.

Air Scoop/HyVent Leaking

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