I have been working to understand whether the amount of make up water used by my brand new (April 2018) Burnham Independence (IN8I) --245 BTU/hr --one pipe system with 13 radiators (there are also 2 small ones in bathrooms that are off). The new boiler has an auto feed with a gallon counter.
All return pipes are exposed, and there is no evidence of leaking. Ditto on the visible supply lines. Ditto on the radiator supply valves ( i put glasses over the valves to ck for condensation)
Last Spring, just after the install, it was still cold, and the boiler was used for about 5 weeks--it used 3 gallons in that time--so I figured there was a problem.
I found that the mains were letting alot of steam out. So, in October, I replaced them with Gorton #2s (there are 2 mains on either side of the house). That seemed to help, but the make up water went to 5 gallons after about 2 weeks in late october.
So, I replaced all the radiator vents--someone had installed verivalves on all radiators--and I put shot glasses over them, and found a significant amount of condensation during a cycle--so, I replaced all of them with what was the original valve for the system --Hoffman no 40s--i know this because the person left the old valves in the enclosures--so I bought brand new ones.
I did the replacement 2 weeks ago--it has been cold, and the system has been working. It now appears to be using about 1 gallon of make up water per week.
I will ask for thoughts about that 1 gallon in a moment. First, my question about the "click" noise the new Hoffmans make---one thing to note--in case anyone out there has hammer noise in a steam system --mine has absolutely horrible for clanking, and hammer--it totally, 100% disappeared with the new Hoffmans--so, if you have that issue, you may be venting too fast.
Anyway, the system works great--radiators come to heat fast, no hammer. However, late at night when the house is very quiet and the steam is on, I can here all the valves periodically making a light, metallic "click", and then I hear gas hissing (escaping)--then the click happens again and the hissing stops--all the valves do this, and they do it multiple times during a heat cycle. It is like a symphony of clicks.
Why do they do this? I assume they are venting air--but why do they close, wait awhile, then vent air? Why doesn't all the air vent, then close when the steam arrives? I am wondering if they are only venting air--and whether the hiss could be steam--remember, these valves are all brand new, so I doubt they are malfunctioning. I haven't had time to use shot glasses to see if steam is venting, but i am assuming they are new and working right.
Anyone know how these things work, and why they'd open and shut multiple times in a heat cycle?
Now onto the makeup water rate of 1 gallon a month. I am well aware of Burnham's anxiety producing chart in its documentation that indicates that a service person should be consulted if an I8 boiler uses more than 3 gallons in a season.
Note that it DOES NOT say that using more than 3 gallons a year is a sign of a problem. All it says is that a service person should be consulted to check the system for leaks.
Burnham is shamefully ambiguous on this point. The manual indicates that a "leaky" system can drastically shorten the life of the boiler--but, it gives ZERO definitive guidelines of how much make up water is too much.
All they tell you is to check for leaks beyond a given threshold for the boiler size.
So, I have done that in spades--there are no leaks on my system (I suppose it is possible a pipe in the walls is leaking, but that seems unlikely to me, given they are vertical and drain completely).
To put my usage rate in perspective: 1 gallon a week / 13 radiators = 9.84 ounces of water loss, per radiator, per week. So, per day, that is 9.84 ounces / 7 days = 1.4 ounces lost a day per radiator. Now, lets say the steam comes up 1x per hour. So, 1.4 ounces/24 cycles in a day = .05 ounce of loss per cycle. These are ballparks, obviously, but they do put the loss in perspective.
So, think about that.--- .05 of an ounce per heating cycle, for each radiator in my system equates to 1 gallon of makeup water per week. If you put a shot glass over the radiator vents, I am confident you will find a properly functioning vent lets that tiny amount of water escape on a given heat cycle.
So,, am I correct to conclude such a rate of water loss is "normal", and not indicative of a "problem"?
So, what do you all think about this? If I take the Burnham documentation to heart, I will worry I am using way too much make up water. But, based on the above calculations--it seems to me Burnham is creating unnecessary confusion about whether "normal" make up water is nothing to worry about. Given the above calculation on the per radiator loss of my system , it seems ludicrous to think a 13 radiator system could function and lose only 3 gallons (or less) per year.