How to test vents?

ChrisJ

I have two Gorton vents on my system and one on my neighbors which I suspect to be leaking.



Reason I say suspect is its hard to tell if its just bleeding extra air out or not.  99% sure my neighbors IS leaking, my two I need to investigate more.



What is a good reliable way to test vents?  I seem to recall someone posting a picture of a pot on a stove with something screwed into it but I cannot find the thread.  I'm wondering if simply turning the vent upside down and blowing into it with your mouth is a reliable test or not?

Christian Garibaldi

the way I have

tested vents quick and dirty is to hold them over a tea pot at full boil and aim the steam at the inlet for a minute or so, then CAREFULLY...bc it will be hot, blow into the vent by mouth. The metal will be hot , so either ice the nipple briefly or wrap it with tape prior to heating. Perhaps others have a different method though

Mark N

Leak Test

Chris what makes you believe they are leaking? If they are closed because of steam, nothing should come out. Sometimes closed vents leak under excessive pressure. Have you tried rinsing them out with water? Maybe there is crud in the valve seat. Also are we talking main or rad vents?



Mark

ChrisJ

To leak, or not to leak

Hi Mark, Thank you for responding.



Radiator vents, specifically two Gorton 6s and a Gorton 5.



I believe one of my neighbors vents to be leaking because after the systems been steaming for a while it continues to hiss while all others are silent.  If I tap it, it will stop for a bit and then start up again.  During this the vent is burning hot so I'm sure steam is passing through it the entire time.  I installed the Gorton's on his system last year some time.  I had considered taking it off and rinsing it out as you suggested, but have not got around to it yet.



On my system, the reason I suspect two are leaking is because this morning during a recovery I noticed two were hissing\sizzling.  One of these is one of the first radiators to get steam and heats very well, which is why it surprised me the vent would be passing anything near the end of a 4 degree recovery.  The same with the second vent I mentioned, except that one very well might have been passing air due to its location and how it behaves, I didn't have time to feel the radiator and really assess the situation.

This is the first recovery\setback I've done since January for a few reasons and I recall one of these vents acting up in the past. 



Can't tell you what pressure because just as I went to look the t-stat shut the boiler off and I decided to just hop in the shower.  I can say for a fact my pressuretrol kicks the burner off at 1.5PSI so it was not over that.



Speaking of that, if I decide to buy a vaporstat, and I may due to the addition of the TRVs, would you recommend the 4PSI version or 16oz version?  I'm thinking the 16oz version would be best for me.

Mark N

Leaky Vents

In theory if a rad vent has closed all the air should be out of the rad. In practice it depends. If the rad vent is closed and you here hissing I would think it is leaking some steam. If you can reliably get your pressuretrol to turn your system off at 1.5psi why would you need a vaporstat? If you boiler is properly sized it should never even cycle on pressure. Save your money for now. I would try rinsing out the vents first and see what happens.



Mark

ChrisJ

Rinsing

I'm going to inspect the vents tonight if I have time.  Pexsupply said they would exchange them for me if necessary so no big deal.  I will try rinsing before sending back if it comes to that.



I'm experimenting more with a setback\recovery because my gas bill went up in February even though HDD went down compared to January.  The main change was I stopped doing my setback because I didn't think it mattered.  This is why I'm also looking into a Vaporstat as I know if I do a 4-5 degree recovery on a 10F day I probably will build some pressure especially if the two TRVs are throttling things, or are closed completely.

Mark N

Gas Bill

Chris



My Feb. gas bill was also higher than my Jan. gas bill. What is your billing cycle. Mine is the middle of the month. My Feb. reading was on the 13th. Don't forget the real cold snap we had in New Jersey was in the beginning of Feb. I pay no attention to heating degree days and the tstat has been at 70 since my power came back after Sandy.

ChrisJ

HDD

Hi Mark,



Not sure of the billing cycle, but I assumed the HDD the gas company provides with the bill go with the cycle?

Mark N

HDD

Never assume anything. For what town is the HDD from? What is the time period? Might be Newark for all you know and for the calendar month and your reading is in the middle of the month. If the reading doesn't come from a nearby weather station it is useless.

ChrisJ

Hmm

I don't know honestly.



It sure would be nice to not do setbacks, I hate the overshoot in the morning.

Mark N

Overshoot

Chris



By how much do you overshoot. It is almost impossible not to overshoot with a steam system. Why not try this. Do your 5 degree set back but set it recover 3 degree. It will most likely overshoot the other 2 degrees and the manually set it to hold at that temp. I've never used a programmable thermostat so I'm not sure if that is possible.



Mark

ChrisJ

Steping

Hi Mark,



I had tried a stepped recovery previously but wasn't happy with it because the thermostat starts early depending on what it feels is appropriate. This changes the offset between say 68F and 70F and can cause the system to run a second time when I don't want it to.



I just removed the two suspect vents and whats strange is if I hold them upside down and blow really hard, I can blow air through them with my mouth. All the other vents I've checked tonight I could not.



That already makes them suspect, though I also don't know how well they seal via the bi-metal strip either. I put two new vents in place of them which I had on hand for now.





Am I weird for having spare vents of every number I have in use on hand?

Mark N

Vents

From what you say it seems they aren't sealing properly. Try rinsing them out and test them again. Under normal use I would think rads vents should last for decades. Having some extra vents around isn't a big deal.

PMJ

Setback/Stepping

To smooth this out and avoid overshooting the recovery must be stepped AND the boiler run time must be limited - that is cycled during the call for heat.



I setback to 65 at midnight(sleep), call for 67 (wake) at 6am, 68 (leave) at 10 am and 69 (return) at 12 noon.



The longest I ever let my boiler run continuously is 35 minutes - and then only after being off continuously(no call) for over 2 hours. After that the longest run is 10 minutes off/10 minutes on 3 cycles an hour. At 20 below outside and no insulation in the brick house once the system is hot I never need more than 50% of the boiler to keep up with the heat loss. Remember, the only time you really need your whole boiler is from a dead cold system startup so you can actually get the whole thing heated up at all. Once the pipes are hot enough to carry steam a much smaller boiler would do just fine.

The PLC keeps track of the total call time and the total burner run time. The burner run time total is always right around 50% of the total call time. This spreads everything out, rads always pleasantly warm, no overshooting.

ChrisJ

PLC?

Ok, you have my attention.



Whats a PLC? 

PMJ

PLC

Programmable Logic Controller. Mine is less than $100.00. Look up TECO SG2 at factorymation.com.

Takes some getting used to the programming but will open a whole new control world with your heating system.

Hap_Hazzard

Extra Vents

This is where the Maid-o-Mist vents work out nicely, because you only need a couple of vent bodies to swap out for leaky ones instead of having one of every size you might need to replace. If you have extra orifices you can also re-size vents that are working without having to take a good vent out of service. I recently got a couple of the ones that come with all five orifices from Amazon.

ChrisJ

Got an idea!

So I decided to buy some parts so I could use my skim port for testing vents.  I will post some pictures after I put it together and try it out.



I expect to hook everything up and have a valve going to the vent to be tested so I can throttle the pressure to it.  I will start with this valve closed,  then with the king valves and return valve closed fire the boiler up.  At this point it will build pressure until the pressuretrol kicks the burner off at 1.5PSI.  Next I will slowly open the valve part way going to the vent allowing the air to be pushed through it at a slow and easy speed.  Obviously once the steam gets to it, it should close and at this point the pressure should build behind it up to 1.5PSI. 



This should be an easy way to hear, and maybe see with a bright light if the vent is leaking.  I would like to add a siphon and another 3psi gauge between the valve and vent to do a bleed down test, but that's just not in my budget at this time.  Will make testing brand new vents easier, as well as ones I have cleaned.



The rig will not be left on the boiler and I bought pieces so I could test main vents and vertical vents as well as the normal right angle ones.

Charlie from wmass

if you hold a paper towel

over the top of the vent. If it gets wet vent is leaking after steam gets to it. If it stays dry it is not leaking steam.

ChrisJ

paper towel

I would never have thought of that.



Appreciate it!

ChrisJ

How tight?!

I'm really confused at the results I found.

I tested the two Gorton's I suspected to be leaking as well as all of the spares I had on hand, and all of them performed about the same.

When the steam hit they would close, but never stop weeping.  Very little leaking, but leaking steam none the less.  All except a brand new Gorton 1, that seemed to shut tight.



I also tested one of my used Hoffman 4As, this also shut tight.



So now I'm really not sure what to think, do I have 5+ Gortons that are defective, 2 of which are new or is a small amount of seepage considered normal?



This test was done with the king valves and return valve closes so I was able to build pressure.  

ChrisJ

Gorton

I spoke with Ken at Gorton yesterday regarding my findings and at this point I don't trust the results of my test. Ken is going to check the vents I tested and let me what he finds.



What I've heard about Ken is definitely true, he is a great guy to talk to and provides amazing support. I highly doubt you would receive anything like this from Maid-O-Mist not to mention the Gorton's don't have any plastic in them and are soldered together not crimped.