Honeywell supervent

eazabors

Hi all!
I have a boiler powered hydronic in-floor heat system that has started to get much louder. I believe there is a lot of air in the system that is causing the vibration and noise.
I noticed a few months back that the zone pump was vibrating, so I took the cartridge and cleaned what I could and replaced it. Seemed to quiet down for a couple months but then it has started to get loud with vibration again.
I also noticed that the automatic air vent installed right on the boiler was spitting out a lot of air/steam/sputtering water. Although this is stopped (I'm thinking maybe clogged?) This is furthering my suspicion that there is a lot of air in the system. I feel like I can hear the air in the second circulating pump.
I believe I need to replace both the vibrating pump, as well as the automatic air vent; but I also want to clean out the Honeywell supervent that is installed on the system. I'm thinking this is/was the first point of failure that ceased to let air escape from the system.
The vent has an air expansion chamber installed underneath it, and not directly underneath it. There is first a Tee that the make-up water line attached to. I will attach a picture, but the make-up water comes in to a Tee from the left. Below the T is the expansion chamber. Above the T is the Honeywell supervent.
As such, I cannot just remove the bottom of the Honeywell supervent to clean out the internal eliminator.
Can I disassemble it by:
1)removing the expansion chamber (spinning it off).
2) loosening the bottom of the Supervent
3) unthreading the copper pipe from the top of the T
4) spin off the T
5) pull the internal eliminator brush out of the supervent?

My plan would be (hopefully) to depressurize the system; clean out the supervent, replace the Taco circulation zone pump (which I believe to be the greatest cause of the vibration and noise), and replace the boiler's Caleffi automatic air vent (which I believe now to be clogged). Then repressurize the system.
Appreciate any thoughts and advice!!!!!

JUGHNE

What temp and pressure does this run at?

eazabors

Off-hand (not at home at the moment) - I believe the make-up valve is set to 12PSI (so that is what the boiler reads when cold). I think it gets up to 18-20PSI(?) when running, and I think the boiler set temp is around 180-190F.
Again- that's a best guess from what I can recall without being able to look at it.

hot_rod

looks like you have valves around the vent, isolate it and remove the top part of the vent to check the valve mechanism and condition of the brush media inside.

Shane_2

Just replaced the top of the Honeywell Supervent for a customer that had air problems. I think the float goes bad on some of those. Supplyhouse SKU: PV-020RP

GroundUp

The biggest issue here is that it's piped backwards. The pump needs to be on the downstream side of the Supervent/ expansion tank in order for the system to work properly. The odds are pretty slim that the Supervent needs any sort of service, but if it does, you can loosen that brass nut on the top and remove the guts without removing anything else.

mattmia2

Does it keep pressure if you turn off the valve to the make up water supply? Air doesn't just appear in a system, it has to come from somewhere. The 2 biggest suspects would be there is a leak somewhere and the air is coming from that fresh water that is replacing it or the diaphragm in the expansion tank is leaking.

Jon_blaney

Had the same thought. Someone else had a similar problem. Most thought there was a leak and makeup water was loading the system with air. While it may be piped correctly, a steady flow of fresh water into the vent has got to make thinks worse, my opinion.

hot_rod

GroundUp said:

The biggest issue here is that it's piped backwards. The pump needs to be on the downstream side of the Supervent/ expansion tank in order for the system to work properly. The odds are pretty slim that the Supervent needs any sort of service, but if it does, you can loosen that brass nut on the top and remove the guts without removing anything else.

With that 4 way valve, the system pump is pumping away from the PONPC.
The boiler pump would be better on the return piping, but it should vent air as piped. It's a small, low pressure drop path from boiler, around 4 way and back to boiler. Looks like an 007 so it is not developing a lot of delta P.

It is piped in the hottest point in the system, that is the #1 mechanism for air removal, lowest pressure is second.

No harm in disassemble and inspection. If it has a lot of mineral scale, that too would indicate it is taking on fill water.

If there is a vent inside the boiler jacket, try screwing the cap closed.

eazabors

Thanks all for the responses! Not sure how to reply to each comment individually - so I'll do it all in this one.

@hot_rod, @shane_2: yes - I can easily isolate and pull the top off, but this only gets me the float mechanism. I can (and have) cleaned this, but I cannot see or clean the concentrator brush from the top. confirmed in the Cleaning CONCENTRATOR section of the following PDF: https://static1.squarespace.com/static/515c4f35e4b03ae0a10f3e47/t/5357ef8ae4b0061a08783ca3/1398271882166/PV_air_vents.pdf

@GroundUp : There is a pump also on the downstream. The system has 3 total pumps. In the bottom pic above, the green one that you see first above the boiler services the hot water tank to the left. The black one that you see in the top left of the pic is the one that is the source of a lot of vibration, which I removed the cartridge and cleaned the pump body a couple months back. This is upstream of the supervent. The 3rd one, is on the very top right of the pic, is what services the 3 heating zones, downstream of the supervent.

@mattmia2: I will test this, but I believe it will. Air likely entered in the system when I cleaned the circulator pump a few months ago, and my theory is the supervent is/was too clogged up to remove that air, with sediment from hard water/flux from the last system maintenance (which ironically updated that replaced an old spirovent with that supervent), and the occasional make-up fresh water input. I agree it shouldn't be just appearing. But there is no known leaks in the system.

@all - any input on my proposed steps to remove the bottom of the Supervent? My biggest unknown is whether the bottom will thread out/down the copper pipe coming from the tee, and if that would then allow me to remove the pipe from the tee.

Thanks again all for your advice!!!

Jon_blaney

How old is the system? Are the pipes buried in the floor. Are the copper or pex?

eazabors

@Jon_blaney the system is about 20 years old. The heat tubes are pex, and the basement ceiling is unfinished, so most of them are accessible. The house does have a 1/2 lofted 2nd floor; those tubes are inaccessible.

mattmia2

Even if there is some dirt in the coalescing media it should have got most of the air out within a few days. You can take the media out and clean it, you will need to unscrew the water feed, hopefully there is a union in there somewhere then unscrew the bottom assembly. While you are at it, hold the tank with the schrader down and let some air out to make sure you don't get water then make sure it is charged to 12psi, the cold fill pressure of your system with it disconnected from the system.

hot_rod

If all else fails, this is a nice 3 function option, disassembles very easily for service, but rarely needs it

eazabors

Hey all -
I'm back again with some more noise issues with my system
Back around the time of the original post - I did end up taking the expansion chamber off and getting the supervent cleaned out (however I wound breaking the solder joint upstream of the expansion chamber to do so). Per the above steps, I successfully replaced the Taco circulation zone pump and the boiler's Caleffi automatic air vent, and was treated to fairly quiet operation for some months. A few months later, one of the other old pumps started making noise, and replacement silenced that one as well. Finally, the 3rd one followed suit. I figured alright - my system now has all new pumps, I should be good for another 20 years!
Unfortunately, one of the recent replacements, the pump in the very top right of the picture (you can only see the bottom flange) is already making quite a bit of noise and vibration
I will try to attach a video (later) such that you can hear it, but needless to say, I was shocked that this was occurring after only a few months of operation.

My question to this forum is - is it possible it is just air in the system making all of the noise? Or am I needing to replace that pump yet again?
If you think it's likely air, what is the best way to flush the system of the air?

Note worth mentioning - I don't trust the Supervent at all... In fact, I can 'force' the valve open by removing the cap and inserting a dental pick tool. Every time I do, some air comes out (maybe 5-10 seconds of quiet hissing) before water starts coming out.

hot_rod

Float type Air vents are designed to maintain a small air space at the top. This is to prevent any debris floating inside from getting up into the needle valve. If only a few seconds of air comes out you are pulling that captive air space 

another possibility of noise that sounds like air is cavitation. It occurs at a pump that has flow restriction. or any place in the piping where glue is passing thru a small restriction. All valves wide open?
I wonder if that 4 way valve is sludged  like the Supervent was. That could cause a reoccurring noise, restricting flow to the circ above it

pumping at the expansion tank, the black pump isn’t helping.

you could put a tee behind the gauge on top of the boiler and connect the expansion tank and fill valve there, then the pumps are pumping away from the tank.

Buy, read, and understand this book

HVACNUT

You're pumping into the expansion tank and 4 way valve..

eazabors

Thanks for your responses.
@hot_rod - yes, all valves are wide open, aside from the 4-way valve which is at about 45 degrees. (I think wide open is at 90 degrees, 45 degrees is mixing - but weighted towards boiler water going into the heating tubes)
I also think it could be/is cavitation.
If that's the case - what is the best way to evacuate the air from my system? The only way I've read about doing it (and have done several years ago) is connecting a hose on the return path (just prior to the mixing valve, cannot see in the above picture), and flushing the system into a bucket until there are no bubbles appearing...

Which book? I don't see anything linked/attached that references a book...

@HVACNUT - yes, there is a circulation pump after the boiler, that pumps through the supervent (and thus "into" the expansion tank), and then into the 4 way valve.
Then there is another circulation pump (and the current one that is the source of the noise), above the 4 way valve, that pumps into the 3 heating zones and turns on anytime any thermostat calls for heat and a zone valve opens up. You can also see the bottom of that pump in the picture. I'll take a better one that shows the full system and post later.

Does that help?

eazabors

This should link to a video of the pump in the discussion that is vibrating/cavitating(?)

https://photos.app.goo.gl/YZFaYDdgumAkCKYf8

hot_rod

eazabors said:

Thanks for your responses. @hot_rod - yes, all valves are wide open, aside from the 4-way valve which is at about 45 degrees. (I think wide open is at 90 degrees, 45 degrees is mixing - but weighted towards boiler water going into the heating tubes) I also think it could be/is cavitation. If that's the case - what is the best way to evacuate the air from my system? The only way I've read about doing it (and have done several years ago) is connecting a hose on the return path (just prior to the mixing valve, cannot see in the above picture), and flushing the system into a bucket until there are no bubbles appearing... Which book? I don't see anything linked/attached that references a book... @HVACNUT - yes, there is a circulation pump after the boiler, that pumps through the supervent (and thus "into" the expansion tank), and then into the 4 way valve. Then there is another circulation pump (and the current one that is the source of the noise), above the 4 way valve, that pumps into the 3 heating zones and turns on anytime any thermostat calls for heat and a zone valve opens up. You can also see the bottom of that pump in the picture. I'll take a better one that shows the full system and post later. Does that help?

HomerJSmith

This is my take on the situation. Yes, you are pumping into the Ex tank as stated, a no no. You would be better served to switch the black pump and the Ex tank's position. BUT... you would be better served to make other changes.

I am basing this on the boiler being a cast iron boiler. I would move the black pump that is on the output of the boiler to the return to the boiler under the mixing valve and then you could keep the Ex tank where it is. The pressure loss thru the boiler cast iron heat exchanger is low. Then you could set the mixing valve for a sustained return water to the boiler above 135 deg and a delivery to the pex zones at a temp lower than 180 deg. To get between these two points may result in short cycling. Do all your pex loops operate at the same time? Do you have a manifold or zone valves?

The way it is piped now, it seems to me that you have two pumps in series thru the mixing valve. That could lead to excessive flow to the infloor heating sys. It could also lead to velocity noise which may be what you are hearing.

The length of the pipe input to the pump should be 10-12 pipe diameters and I always use a pipe length of 5 pipe dia on the output before making any directional changes. This would keep turbulence in the impeller to a minimum and help reduce noise from the pump.

Pics of your sys from further away would be helpful.

HomerJSmith

Addendum. The coalescing medium is stainless steel and is accessed thru the bottom nut. It has an O-ring seal which I lubricate with silicone grease or I replace that O-ring. You can pull the medium out of the body with pliers and clean the medium.

I had a case where the medium was sooo gunked up that you couldn't see thru the medium and the water was running around it. It wouldn't clean up so I sand blasted it. It came out pristine and I replaced it and the float assembly. Wala, that's stainless steel.

mattmia2

Cavitation isn't caused by air, it is caused by the pressure in the pump dropping to the point the water briefly flashes to water vapor. Your multiple circulator and relationship to the expansion tank could be causing that. If the air separator or one of the strainers became plugged that could cause enough pressure drop for cavitation too.

You could be hearing cavitation or cavitation could have damaged the circulator over time.

Another possibility is you are still getting fresh water in to the system but the auto vent is working now so the air from it is being removed but the oxygen in that fresh water will still corrode things like the circulators.

eazabors

eazabors

Thank you again for all of your continued responses. I have uploaded some pictures from farther away, to give a better overall view of the system; which should help answer some questions as well.

@hot_rod - I mentioned above about the 4-way valve not being open all the way, I now believe I was wrong there. I think 0 degrees is mixing 50/50; it only turns +/- 45 degrees. So -45 degrees would be mostly directing back to the boiler, and +45 degrees is fully open; is mostly directing straight to the heating zones. I just played with that a little. A couple findings.
1) the valve was pretty stuck when I first went to move it - needed to remove knob and turn with pliers
2) the noise is worse, not significantly but noticeably, when the valve is -45 degrees vs +45 degrees
3) changing the valve between -45 and +45 also results in what sounds like some air movement, but could also be the expansion tank or make-up valve introducing water into the system?

@HVACNUT @HomerJSmith - The pics above now show the upper part of the system, including the zone valves. MB = master bedroom; Loft = the 2nd story of the house (of which there is 2 small bedrooms and a bathroom); LV Room zone includes the rest of the house. Another interesting finding with regards to the zones...
1) The Loft zone being open makes by the far most amount of noise, regardless of if the other 2 zones are on.
2) The LV Room Zone open alone makes the least amount of noise, almost quiet operation, even though the MB zone is on the same floor (although farther from the boiler) but a much smaller zone, maybe 1/4 the size

@HomerJSmith - yes, it is a cast iron boiler. the pex temps appear to be at around 140 degrees (via IR thermometer). the return temp appears to be around 108. That said, I now don't trust my IR thermometer, it told me the supply towards the hot water tank was only 75 degrees, but it was way too hot to touch... It also said the concrete floor was 65, but my freezing cold feet would disagree! (anyway, some temp validation will be required...)
The loops do not operate all at the same time (see the comments above)

Re: excessive velocity. If 2 pumps on either side of the mixing valve is the issue, would one potential fix be to disconnect one of the pumps? (If I were to do that, which one would be the better one to disconnect? I assume I would also want to remove at least the cartridge/impeller instead of letting it freewheel?)

Regarding the length of pipe for input/output; I'm not sure I understand where I would be measuring from to confirm my system complies with that rule?

And yes - regarding cleaning the supervent medium - see initial thread for the challenges I had there. I was able to get to it eventually, and clean it - it needed to be cleaned... but it is not any easy process for my system unfortunately...

@mattmia2 - I was not able to identify any leaks in the system and per your suggestion last January, I checked to make sure there wasn't water in the expansion tank.

Thanks again all!

HomerJSmith

This pump should be a ECM pump because the Zone Valves can operate independently and there isn't a differential pressure bypass valve .
When using a IR thermometer, the emissions from copper pipe could lead to a inaccurate reading. Put a strip of black electric tape on the pipe and shoot the tape.
I wouldn't disconnect the pump, which is pumping into the Ex-tank or the other pump, but move that black pump to a different location as stated. Your pics suddenly shows the black pump turning into a green pump.
The problem with multiple zones is that they are probably not balanced and water will flow thru the shortest zone and less so as the pressure loss of other zones increases. I always use balancing valves on multi-zone systems to provide the proper flow in terms of GPM to each circuit. It's hard to determine the source of the noise. It may be velocity noise or air noise, etc.

hot_rod

You only need one circulator.
However without an automatic control to adjust the 4 way, the supply temperature will change as zone valves turn on and off, as the flow rate changes, but the valve cannot respond That is the downside of a manual 4 way.

He is a basic 4 way piping with a single circ.

You might try disconnecting the power from the black circs, the black one, just remove the wiring cover and disconnect the wire nuts. With all the power turned off, and a meter to confirm!

The boiler piping could be better.

Is that black rubber radiant tube?

eazabors

@HomerJSmith Thanks for the tip on using the e-tape - I'll give that a shot tomorrow!
Yes - the black pump turned into a green one early last year - that was the first one that got replaced
I'll look into adding balancing valves.

ECM pump - looks like this would be the direct replacement?
Taco-007E-F2
Based on the the top couple reviews - seems maybe I should replace all my pumps with these and keep the old ones for backup!

Temperature question - you state above " delivery to the pex zones at a temp lower than 180 deg"; I think it's probably only 150 or so right now when it enters the pex. Does this mean I can increase the boiler temperature to increase heat a bit? On the coldest of winter days, I have a hard time keeping the master bedroom (3 external walls, at the end of the house) warmer than 60 degrees (the wife doesn't like that very much...).

@hot_rod - I'll try disconnecting the circ pump nearest the boiler tomorrow, such that it's only the circ pump down-stream of the mixing valve that is powered (and of course, safety first).
If that works - would you still recommend changing to an automatically controlled 4-way valve?
Yes - the black rubber is the under-floor radiant tubes returning


In summary - seems like I should:
Add balancing valves
Change to ECM pumps
Update to an automatic 4-way valve
Disconnect the first circulator pump
Increase boiler temp to get closer to 180 at the pex

dko

If you are willing to spend all that money, please spend some on actual pex connectors!
If going to buy an ECM pump, buy a smart ECM pump such as the Viridian VR1816 and use the proportional pressure mode.

AFAIK, black pex is Viega. Potable pex is all black and oxygen barrier is black with a red stripe. I do not see any red lines on your pex but can't see much of it so the stripe may be on the other side. Can you confirm it says Viega Barrier on the piping?

Also make sure the supervent vent cap is open a full turn

hot_rod

While ECM circs are nice and save energy, in your case , really no need for one on the indirect. The 007 you have at the mix valve is a flat curve type circ and with only 3 zone valves it is close enough.
My rule of thumb is 4 or more zone valves you want a pressure bypass or deltaP circ.

I would spend money on a better 4 way with actuator and control for outdoor reset. That will better solve the temperature supply issues, protect the boiler from cold return and save a bit of fuel cost by modulating the boiler output. Probably add some comfort also as the SWT will stay more consistent.

So my must do list would be to move the expansion tank and upgrade the mix valve.

If you have money left over, upgrade the system circ, save that 007 for an indirect spare

Air purger before the indirect take off would be nice. Or where it is now
Expansion tank on boiler return or at air purger


With rubber hose, I would add a cleaner and power flush.