Loud hissing from nearly all radiators during this cold spell

Great video. I did jump advance through parts of it for time, but here is what I see:

• overall operation is fine, I see no sign of carryover/surging (as evidenced by your relatively steady waterline
• Your Gorton #1 is definitely busted. Replace it. I like Maid O Mist because they are cheaper and basically the same, but they both fail (as evidenced by your video). Interestingly, people here crap on MoM all the time because their seams aren't soldered like Gorton is, and here is a soldered Gorton that doesn't even look old clearly split. I shop at supplyhouse.com
• Your Gorton #2 seems to also be leaking at .5psi and it should probably be replaced. You could take it down and try to shake it or smack it in hopes of dislodging something inside that is preventing it closing but I have not had success with this.
• These vents leaking is not causing you any trouble upstairs. But it causes the loss of water from your system and that is something you should address to prevent excess corrosion of your boiler.

PS: Note that everything leaks more with higher pressure. You might consider avoiding thermostat setbacks so that your pressure is kept to a minimum (I assume your system sees lower pressure during normal operation and only goes higher when you bump up the thermostat as you did for this video)

For comparison, I have a low pressure switch tied to a timer relay that interrupts all my calls for heat when my pressure gets to about 1/4 psi. This makes it take a long time to recover from a temperature setback of course, but the result is very low pressure and wasted fuel (I consider fuel that goes into pressurizing a steam system to be wasted, even though it somewhat isn't)

If my system were running at 2psi I'd probably have leaks all over the place LOL

To answer your notes above:

3. Your #1 vent for sure is hissing because steam is escaping through that leak in the seam
4. There are two types of steam vent: Those that have failed, and those that haven't failed yet

if it works, it works!

Call supplyhouse and see what they say but maybe come at them a bit lighter than above lol they are good people

You may find on a normal call for heat that you see almost no pressure

I watched the end of your video. That pressuretrol calibration isn't awful. It cut-out at 1.8 and cut-in at 0.8. So differential is accurate at least. When you don't have leaking vents the time it takes to go from 1.5 to 1.8 will be a few seconds and it will not be so quick to go from 1.8 to 0.8.

Your Gorton #2 is hissing under pressure so that will have to maybe be cleaned with vinegar and if that doesn't fix it you'll have to replace. 3 Gorton #1 are pretty close to one Gorton #2. You could do an antler of 3 Gorton #1. If one goes bad it isn't such a huge $$$ hit.

PS: Nice thread takeover 😃

I think it can be luck. I and many others had Gorton #1's arrive DOA

Just unscrew that street elbow maybe 45 deg, then put one holdback wrench on the street elbow and the other wrench (use a large adjustable) on the Gorton and unscrew it. Then reverse the procedure with the new one, or design an antler tree for 3 #1's.

Having multiple vents fail at the 6 month mark tells me something is very wrong, call supply house and see what they can do. If they can't help a call to Gorton is in order.

My system runs at 12oz but back when it was at 2PSI the vents made only a very light hissing noise.

Hissing vents makes me think your pressure mat be higher than you think. Maybe the pigtail is partially clogged? Your pressure gauge might be lying, the 30# gauge is pretty useless - think about adding a 0-3 gauge so you can see what is really going on. Pressure sb kept under 2PSI.

Bob

First, you don't really need clean water. It's fine to let it get a little brown. Toward the end of the heating season you can add a couple gallons and flush one out to reduce sediment buildup.

But the key is to increase the pH of the boiler water. See my video:

https://youtu.be/Bx8NryCUkng

The most important consideration for having clean water is to stop adding fresh water! Fresh water has plenty of oxygen which causes corrosion and makes rusty/muddy water. It sounds counterintuitive but the more clean water you add, the dirtier your boiler will be.

Find and fix those leaks! Before I knew better I had a leaky radiator. It was on the top side between sections so it only leaked steam so I didn't really care as it didn't make a mess. During the cold spells I was adding a couple gallons of makeup water weekly. I thought this was normal. I always had muddy water no matter how often I flushed it.

I fixed that radiator and now I only have to add makeup water once or twice per season!

RectorSeal 8-way also helps considerably. It has some magic chemicals in there but it is really good at adjusting the pH of the water. A pH of around 10 will essentially stop corrosion inside the boiler so the water stays clean much longer.

Every now and then I drain a bit out of the boiler drain and float LWCO and it comes out completely clean. No sediment at all.

Just be aware that the directions on the 8-way are more for commercial boilers. Use 0.75-1oz per gallon of water in your boiler. The 8-way will also do some cleaning so you may find your boiler water getting cloudy. That is all the scale and junk that has built up over time. After the first year or two of using 8-way in my boiler it stays nice and clean and clear.