smaller rads not heating

4Barrel

i have smaller rads that are behaving strangely, the rad vents (hoffman 1As) are quickly filling with condensate, rendering them inoperable. the rads go cold unless i remove and drain them, but the cycle quickly repeats. of course, as soon as i remove the vent, the rad gets hot, and i get steam out of the vent port. i cleaned the vents out with a little soapy water thinking they are becoming clogged with debris, but i don't think that's the issue, as it continues to occur. this is happening only on a few smaller radiators, one in particular. they are pitched properly for drainage. everything else in the system (other larger rads, main vents, etc) is running pretty smoothly. i'm speculating that the rads themselves might be clogged, and are filling up with condensate, but is there anything else i should be considering?

my system is one-pipe steam, dunkirk boiler, main runs insulated, pressurtrol control, etc.

thanks.

Alan (California Radiant) Forbes

Make sure

the valve at the radiator is fully open to allow the condensate to drain back to the boiler.

4Barrel

valves fully open

sorry, should of stated that. yep, valves are fully open.

JStar

Vents

Well, let's have a look at the entire system. Any pictures of the boiler and piping? Main vents? Pressure?

4Barrel

pics

sorry for delay... here are some pics of the boiler, near boiler piping, and the system vents... i don't have a pic of the problem rad, as it's in a tenant's apartment, but like i said, the rad is pitched properly, and the vent itself seems ok (i've tried a spare to be sure).

the system vents are positioned at the ends of the returns, and I have four positioned at the ends of longer branches from the mains (two vents on each). i've experimented over the last couple season, and this vent arrangement/sizing allows fairly even heating in the building.

ChrisJ

Hoffman 1A

I had endless problems with my Hoffman 1A's getting a tiny drop of water in the valve orifice and the radiator would stop heating until I cleared it using a can of air with a straw.



It happened randomly but primarily to radiators with long runouts. I switched to Gorton vents and the problems went away.

4Barrel

were they older?

were those 1A's older? or did you have trouble with newer ones as well?

over time, i've swapped out older with newer, had some issues with newer ones, went back to older ones that i cleaned, etc, etc. ugh. this is just a general observation.



the issue i have now seems to have started since it's been really cold, and the system is cycling more often. not sure that has anything to do with it. these particular rads are not on the longer run outs.

ChrisJ

2011

I bought all of the 1As in 2011 when I replaced the boiler. We had just moved into the house so I have no info on what took place before then.



I'm a homeowner not a pro but my opinion is replace the ones that are giving you headaches with the appropriate sized Gorton and see what happens. I bet the problem disappears.



I might be crazy but I think my boiler uses more water with the Gortons than it did with the Hoffman 1As. The good thing is all of my rads heat every cycle.

4Barrel

more water?

just so i understand, more make up water with the gortons? that's interesting!



getting on a tangent here, but i think it relates to the vents: i see all the posts stating how little make up water a properly operating system should be demanding. over the past couple seasons, i've replaced sections of the main that were rotten (prior owner did not insulate). i thought i found all the leaks. but the system is still taking on make up water (via autofeeder) on a regular basis. it's improved, but still leaking. and there is no clear evidence of where.



this leads be back to the rad vents. assuming i've corrected my piping, are the 1A's prone to leak? even when operating "properly"?

ChrisJ

Leaking

All rad vents and main vents will loose some steam, there is no way around it. I also believe you loose some water via moisture in the air that gets pushed out before the steam even hits the vent.



As far as how much, it appears my system uses around 2 cups a week during a very cold week. This would mean 1/2 gallon for a month assuming low temperatures.



From what I have heard a leaky system often uses gallons per week. I am a big believer in boiling the water immediately after adding it. I often will go down and add water right after I hear the burner fire up so I'm adding it slowly as it starts boiling. I also use steamaster water treatment to reduce corrosion in the boiler. I do not have an auto feeder but if I had one just for emergencies I would still manually add water as I am now.



In my non professional opinion below is what most commonly causes a steam boiler to rott out.



1: Adding makeup water and not boiling it immediately.

2: Low PH.

3: Leaks in the system causing excessive makeup water.



I'm not positive but I also suspect running the boiler low on water is also bad. For example waiting for the LWCO to trip and force the autofeeder to fill the boiler. I fill mine to around 1/8" above the NWL and add water and it's about an 1/8" below the NWL.



The previous owner of my house had a block rott out in 3 years and then the second rotted out in 5 years just when I bought it. I believe this was due to many leaks and slightly low PH. The boiler was easily using a few gallons a week and it was being fed 100% by an autofeeder.

4Barrel

helpful

thanks chris - very helpful info.