Understanding the boiler fill valve, this weeks video

RayWohlfarth

In this weeks video, it talks about the boiler fill valve or PRV. Do you leave the valve feeding it open or closed? Hope you enjoy it.

https://www.youtube.com/watch?v=vMcW8v8bT5U

Budward

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.

RayWohlfarth

@Budward Thanks for watching. Hope you figure out why the pressure is low

gselestow

Great video Ray!

Mark Eatherton

Great sleuthing Ray. If the system has a LWCO, I close the makeup off and instruct the customer about correct pressures etc. If it doesn't have a LWCO, I recommend its installation. Water damage constitues the majority of insurance loss claims… No leak is a good leak… If you're losing pressure, you need to figure out why (as you did) and correct it. AV's on the inlet side of a high head pump that is pumping towards the PONPC will cause air to get sucked into the system, and cause early failure of the AV. Been there, seen that hundreds of times. You can compensate by raising operating pressures, but that's not a fix, but rather a temporary solution. Need to move either the pump or the PONPC (expansion tank) to correct it. Great work. Good to see you're still active and paying it forward. Keep up the great work.

ME

Gerry_P

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.

RayWohlfarth

Thanks @gselestow I appreciate it

@Mark Eatherton I appreciate it Mark Troubleshooting the rising pressure takes patience. I appreciate the comments and hope all is well with you

@Gerry_P Thats a great idea. If I did residential work, I would have given the customer a sheet showing what to look for and the normal readings.

hot_rod

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

RayWohlfarth

Thanks @hot_rod and Happy Belated Birthday. I hope it was nice

hot_rod

think, Ray

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

metrosilo

Bit more work but you can use a pressuretrol with a solinoid or actuator (belimo) rather than the old school spring style PRV.
Also, my eyes tend to go to the expansion tank when there is no pressure as well as checking feed water. Could be water logged etc.

I keep my feed valve open. 😀

ethicalpaul

Really great video, thanks Ray!

hot_rod

https://forum.heatinghelp.com/discussion/comment/1818042#Comment_1818042

I've always kept mine and my customers fill valves open. I've never had a flood issue so I'm comfortable with the choice.

I suppose if you are plan on closing the valve after a fill, why bother even installing a fill valve. Delete the fill and BFD, just fill with a hose :).

It saves the cost of the BFD recertification also if it is a RPZ type that requires yearly inspection.

ccstelmo

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

RayWohlfarth

@ccstelmo wow you bring up some good points