boiler filling normal vs really cold winter temps

The guy on YouTube is probably referring to water being added too often because of leaks, faulty air valves and things causing water to be introduced when it shouldn't be. With how cold it's been your certainly going to refill more often than you would with typical temperatures. If your boiler is working properly, no leaks in the system and it's simply getting water added because of extra usage then you're fine

That sounds like possibly too much water. You don’t say how much but it sounds like a couple inches every two weeks.

I’d try to get it 1” per month. Look for steam leaks especially if you set back your thermostat

PS: why let it get low enough to flash lights? I’d refill it whenever it was 1” low

Then log each addition of 1”. You might be using more than you think

You have a serious leak(s) if you are adding 2 quarts in 3 days, no matter how cold it is out.

it does not close at all due to the wet steam

Just for my education about people's thinking, can you tell me exactly what you mean by "wet steam" here?

Does your water level drop in the gauge glass significantly during boiler firing?

@ethicalpaul, my mains and returns are above ground and have been checked for leaks by me as well as by other plumbers. The risers are in the walls but none of the walls show any evidence of leaks unless the water is evaporating on its way down. All the visible pipes have fiberglass insulation while the risers have the original asbestos. None of the radiator valves leak. Only the vents, and only 2 at the moment, are spitting water. So, short of pressurizing the system or using thermal imaging I have no way of telling if the system leaks or not. Resorting to these measures here in Westchester is next to impossible as there are no HVAC companies here that can do these diagnostics. The BMs did leak steam, but since changing to silicone O rings they have been working perfectly for the past 4 years.

When it comes to the type of rad vents, both the Hoffman and Ventrite float types have been good at closing shut. In the bimetallic types, the MOMs are the next best but the Gortons haven’t worked at all for me. My steam carries a high percentage of suspended water in it and when this wet steam hits the float type vents they still move up and close the orifice perfectly while the bimetallic types don’t in all cases. Every design in each category is a bit different though the operating principle in each category is the same. Then there is the issue of manufacturing QC that I will not delve into.

Per your definition, I have a significant carryover. At a pressure of 0.6PSI my water level drops 4.5” from the boiler mark. For the past three days, the boiler pressure has inched up to 0.8 and the boiler occasionally cycles once on pressure even though it runs for 25-30 mins 2 times per hr. instead of once every 1.5hrs at higher ambients than at present.

@Captain Who, I have tried the Varivalves in the past; they work very well until they don’t because they succumb to rust particles. I was taking them out and cleaning them every month, perhaps more often. I am inclined to try them again since I believe more rust is being inhibited by the 8-Way. I might be able to stop the two spitting rad vents by operating the boiler with the water level 1-1.5” below the water mark while I get the Varivalves tomorrow from Amazon. Since my boiler has logged over 12 hrs yesterday and 10 hrs the day before, I’d say the duty cycle is north of 45%.

Thanks to you both for your insights.

I would say your doing good , you seem to be on top of things .. Its hard to find those small leaks , and the larger the system gets….

thanks for the report. Yes by my definition you have significant carryover (not suspended water in your steam) and you should address that. Your vents will all work better.

Have you ruled out a boiler rust hole by flooding it and looking for water running out under the boiler?

Your usage seems high still, but maybe it’s just spillage from the various vents which can add up fast.

under some circumstances the velocity of the steam can be enough to pick up the condensate and make vents spit too, sometimes slowing down the vent can help regardless of if it is just some water sitting somewhere or a lot of carryover

Varivalves fail "upwards". That means they still kinda work even when internals plungers has disconnected from the bellows.

I've made a video about it (if you care):

yeah, those are weird valves. that said, at least one of my radiators i'm keeping the "broken" valve on it because it "works" so well.

Paul, I have not checked for boiler leaks since my boiler is relatively new( in its 4th season) and the water consumption is similar to the 2022-23 season when we had a long cold spell. I agree with you that without leaks the water consumption should be zero regardless of the ambient. But with lower temperatures, the boiler runs more frequently and longer, magnifying even small leaks in the the boiler, pipes, valves and vents which might not be very apparent.

I’m still trying to crack the code on how to reduce carryover and slow the boiler rusting process—basically attempting to keep a juvenile metal beast from eating itself. It’s turning into a full‑blown Sisyphean hobby, especially since half the homeowners on HH seem to be running secret research labs devoted to this very problem.

Meanwhile, I watch videos of your system operating at near-mythical perfection—no carryover, no rust flakes the size of meteorites, and only a dainty cup of makeup water per season—and I am filled with equal parts admiration and existential envy. Admiration because your setup is clearly a one pipe unicorn, and envy because the rest of us mere mortals are stuck babysitting boilers with “quirks” that would drive a shrink to drink.

So many things go wrong that we basically have to live in a permanent state of cheerful self-delusion, treating every weird gurgle, bang, hiss, and outright tantrum as if it’s a solvable engineering puzzle, instead of what it really is: our systems developing new warts just to drive us nuts.

Captain Who, using steam systems requires one to embrace stoicism. I have learned not to fight with them but to live with their failings as long they produce heat. Doing anything else will compel you to pursue some of life’s finer things like plotting Ventrite graphs of opening temps and pressures which predictably takes a 20 yr chunk out of your life.

I have had good experience with the green colored Ventrites of yesteryear, the one I got now is blue, notwithstanding this technological breakthrough, I never believed that changing the vents would be the end of this saga.

But I live with it, enjoy the shared misery and carry on.

not zero, in fact I just added a gallon yesterday. This cold snap is making every boiler use more water.

I probably use more than a lot of folks because my low pressure switch/timer relay setup means even more interruptions in calls for heat than if I let it get up to 2psi like my pressuretrol wants to do.

Each of those interruptions is a loss of all the humid air in my system and an “inhale” of dry air from my house.

But I only add freshly boiled distilled water so it doesn’t bother me.

I’m glad your boiler is intact! Your Big Mouth vents might be losing a decent amount of steam when closing, I know mine did when I had one