Understanding the boiler fill valve, this weeks video

Thanks. I was just looking at my fill valve a couple of hours ago. Puzzled why the pressure gauge on the boiler is only showing 7 psi, even though the (non-adjustable) fill valve is marked 12 psi. And yes, the manual fill valve is between the fill valve and it is fully open.

Great video Ray!

Once the system is at it's cold pressure, around 10 PSI, I close it.

If a leak developed in the system at least it won't flood the house. But homeowners need to be educated about their hydronic heating systems. I always gave my customers a rundown of how the system works and to periodically check the pressure/temp gauges, both cold and at running to make sure all is good. It's not like a forced Air system where all you have to worry about is changing an air filter once a year.

have a low water or low pressure protection with the valve closed

But the boiler may lock out also, so a control or a wifi stat to notify you the system is off

think, Ray

A great birthday, we found our dogs that had been missing for a week in the mountains.

Really great video, thanks Ray!

Out here in the wild west, also known as "flyover country", using propylene glycol to protect our hot water heating systems is second nature (at least, that's my memory, but then again I haven't been in the game for a long time). When I was in the game, though, I always felt that maintaining the integrity of the heating system was Job One so that, at least when the power finally came back on, the house could be heated quickly and all the water distribution leaks could be located, the cracked toilet could be replaced, and the meat in the freezer thrown out. Figuring out how fill valves fit into that world finally lead me to the understanding that they don't because the automatic, indiscriminate, random, and clandestine introduction of water into a glycol system eventually degrades the protection that it's supposed to offer to freezing up. That is, unless you want to crank into your bid price the cost of a glycol feeder. And you don't, because the idea is to be the lowest bidder.

Fill valves cause more problems than they solve. (Oh Oh! Did I just start fight? I can imagine the Dead Men, and a few live ones too , sitting up in their chairs about now). But think about it.

When I was coming up I remember old timers saying things like "well there's always a little leakage from the system". Until the advent of sealed bearing pumps I think a guy could get some traction from such a statement but now - not so much. I mean, do we have a "Closed System" or not? I mean, what is the proper response to a leak in the system, fixing the leak or disguising it with a fill valve?

And here's another thought. Every time a fill valve lifts and squirts a little water into a system it is also squirting a little dissolved air in there. So guess what? Using fill valves implies using automatic air vents. We've all seen what those automatic air vents look like after a few months. They're encrusted with mineral deposits. Those mineral deposits were entrained in the boiler fluid, so I guess they're automatic boiler fluid vents too, right? So we're venting boiler fluid and air out of the vent and this gives the fill valve a reason for being. It must feel worthwhile.

Now, not to belabor a point, but installing an automatic fill valve requires, by code, the installation of a back flow preventer. Are we shooting ourselves in the foot here? I mean, do we want this job or not? Because if we do we're sure cranking in a lot of expense. So what's the solution? (You've probably guessed I have one).

I used to follow our local heating guru around. I snuck in the back door at the end of the day when he was driving off. His name was Pete. As well as being a genius, he was an artist. Pete didn't know it but he was my mentor. Once I cornered him long enough to ask him how he dealt with air since he didn't use air vents - anywhere, anytime, ever. What Pete said to me was seminal. He said you can choose either to try to eliminate air or to control air. And that eliminating air is a fools game because you can't. Air comes with the fluid - period. When he piped he piped so entrained air would have a smooth path back to the boiler. No air traps. He reamed every single pipe cut he made. He was a fan of bending temper pipe and used manufactured elbows only under duress. He viewed boilers as a "wide spot in the road" where air easily dropped out of solution and could be captured and routed to hades, otherwise known as a compression tank, there to languish unto eternity. That compression tank was a plain steel tank not a bladder tank and it's function was two-fold: first to capture air (and BTW, the air quickly became nitrogen only since the oxygen portion interacted with the steel of the tank and became locked harmlessly up as iron oxide) and second, to provide for system expansion.

Alas, the industry has been seduced by gadgets and processes promoted by manufacturers in pursuit of profits. Bending temper pipe is no more and plain steel tanks are near impossible to find. Boilers with friendly taps on their tops for compression tanks too are gone forever. Copper is an expensive antique.

And what are we left with? LED idiot lights, printed circuit boards, modular repair boards, planned obsolescence, 800 numbers manned by heavily accented people reading from scripts and decision trees. Alas Babylon.

For me, the days of communing with, being one with, even intimacy with, heating systems are gone. I couldn't make the transition into the brave new (soulless) world of modern day heating. But I "do not go gentle into that goodnight". I "Rage, rage against the dying of the light".

ccstelmo