on going argument

noleakoete

I am having an on going argument with my fellow colleges ( Plumbers ). After you have filled your residential boiler ( hot water ) all your air is out everything is running good. 12 to 15 psi. I should be able to close my makeup water ?

hot_rod

tough call

if you turn it off too soon you may have some call backs.



Radiant systems can burb small air from the micro bubble resorbers for days or weeks after the start up.



If you have radiant with rubber tube, they are notorius for needing some additional water every heating season start up.



If you do turn it off, make sure you have a good low water cutoff properly located to protect the boiler and circs. A LWC is a good idea even with the fill valve left on.



My thought is if you are going to turn it off right away, why even install one? Keep one on the truck and move it from job to job



An Axiom fill system is another option, and a very good idea on glycoled systems, which should never be connected to a water fill system.



Look for an Auto-Fill valve. Some brands have a set it and forget it dial. Set the pressure and it fast fills without a bypass, and regulates the pressure to the exact pressure you dial in.



hr

kcopp

If you have....

a LWCO you should be able to... I do w/ my system. In fact some say you should lest you have a lock out and a freeze up....kpc

Viess

PSI?

So what would be a safe low PSI cut off setting? Viess.

Jean-David Beyer

I should be able to close my makeup water ?

In John Siegenthaler's big book (page 490), he recommends turning off the make up water (unless you have a metering makeup feeder), but to turn it off only after a couple of weeks so that your air extractor can get all the dissolved air out of the system. The owner should check the pressure periodically.



I am not a professonal, but I thought to follow that advice. When my system was first installed last May, I left the makeup turned on because the only thing running was the indirect hot water heater, and that zone did not even go through the air extractor. The obvious air would come out in the outer jacket of the tank-inside-a-tank water heater and an automatic air release valve would take care of that. Sometime around last September, the system would heat the house a little bit, but it seemed I had not run it enough to get the air all out (the dissolved air). One of the circulators made a noise that suggested air bubbles when the water was hotter than previously. That noise is almost all gone now, but it has been way more than two weeks; more like five months. Probably the air comes out more slowly than I would have expected because the system operates at such low temperatures (120F max in the radiant slab, and 135F in the upstairs baseboard zone, and I doubt either of these temperatures has been reached). The circulators do pump away from the expansion tank; the expansion tank is connected to the air extractor through a T and the makeup water enters that system at the T.



I have had the makeup water off for several months and the pressure has not gone down, so I infer there are no leaks. I check the pressure almost daily (I pass it every day when I get my car), which is regularly, but it may be too often. I do have a McDonnel & Miller probe type LWCO.

Unknown

I would leave it on,,,

especially if there are apartment units on the system,,,, a tenant on the lower-floor feels cool then they try venting the rads,, or if the valve-packing leaks slightly,, no-one ever tells the "super" unless there is a flood,,, Sunday snowstorm calls,, very stupid,, the feeder lasts no-longer on or off,,, so,,,,,,,,,,,,,,,,,,,

Unknown

I check the pressure almost daily

JD are you alright??



Sanity does not depend-on a heating system pressure guage,,,,,, unless that`s the "Linus" approach.

Big Ed_4

It Depends

Some you can and most you can't .... I am all for shutting them down but it's not a perfect world ..

Jean-David Beyer

I am not the expert around here...

In J.S.'s book, he recommends leaving the makeup water off (once all the air has been removed). He does say you need an LWCO to do this. He also says  it is controversial among heating professionals. I think the context of his book is for residential and small commercial buildings, not larger multi-unit apartments buildings or hotels.



Furthermore, when this topic came up the last time, Dan Holohan agreed with J.S.



You might find this item interesting if you have not read it in a while.



http://www.heatinghelp.com/article/11/Hot-Tech-Tips/203/Low-water-cutoffs-belong-on-ALL-boilers

Jean-David Beyer

Am I alright?

As far as I know, I am OK.



I am pretty sure I do not understand your remarks here.



Are you informing me that the pressure gauge on my boiler is not super reliable or accurate? I am not surprised. I very much doubt it is accurate, but it seems precise enough to be repeatable, at least while it is still new.



Are you telling me I cannot tell if there is enough water in the boiler by reading the pressure gauge? I know that. I rely both on the LWCO and the controls of my boiler, whose manufacturer says that in many localities, the controls are an adequate substitute for an LWCO. I do not know if that is true here, but my contractor puts an LWCO on every boiler. (My old 55 year old boiler had neither an LWCO nor even a pressure relief valve. Apparently it was good enough back then when they built this house.)



Your remark about Linus baffles me. I doubt you refer to the chemist, or the software developer. And the kid at the toy piano is Schroeder, not Linus. ;-)

Al Letellier_21

feeders off ??

Not a bad idea, as long as you have a PROPERLY MAINTAINED low water cutoff.

I would see a lot less damage in homes through my insurance work if this were standard proceedure for heating systems. Just like the main water shut off to the home, much less damage if people would shut off the supply when the home was unoccupied. I actually witnessed a summer home that was damaged so badly due to a freeze up and a massive release of water that the home had to be torn down and rebuilt.

Shutting off the feeder is a great idea, think I'll go shut mine off......

Kevin_in_Denver_2

M.E. has the answer

Mark Eatherton developed the "PIG" which is the perfect solution to this problem:



"Nice work Paul.

Jeff, ALL of our jobs have 2 expansion tanks on them. One as a

reservoir to compensate for minor fluid loss associated with initial

air elimination during start up operation, and the other to act as an

expansion tank.

We do not make a solid connection to the potable water system, we DO

have low water cut off protection, and in some cases low pressure cut

off, and you can put low pressure audible alarms on the same LPCO

function.

This is a REQUIREMENT of our insurance company, in order for them to

continue taking our money and MAYBE cover any claims we file...

Our local inspectors wish it was mandatory by code.

No leak is a good leak.

ME"

Steve Ebels_3

That's the way we do it

I can't remember the last install we did that was even connected to the fresh water side of the plumbing.  

Charlie from wmass

I am licensed to connect to potable water

We always connect to potable water with hard piping and leave the feed on. a flood is easier to find and fix than a mystery drop in water pressure that requires a call back when the L.W.C.O. shuts off the heat. This is also helpful in negative training of finish carpenters with cordless nail guns. A half gallon of water they can ignore, fifty or so they have to call and confess what happened. Ask me someday how I know that.

Mark Eatherton

Just guessing Charlie...

But I'd bet a donut to a dollar, that if you asked your insurance company what their preference was as it pertained to keeping the valve opened or closed, they would prefer closed.It is so easy to install a pressure switch with an audible alarm to let people know they are in trouble before they get REAL Deep into trouble.And, does anyone know what the NUMBER ONE residential insurance claim is on an ongoing annual basis? Water Damage...NO leak is a good leak. Leaving the water on and allowing undetected leaks to continue leaking contributes to black mold and other extremely hazardous issues. In my professional opinion, it is WORTH the extra time/material and effort to turn it off. Been there, seen that, have the insurance claim forms to prove it :-)ME

Nick W

B&G says somewhere:

"WARNING: Injecting cold water into a boiler that has overheated due to uncontrolled firing and/or improper water level control, can cause excessive stresses in boiler components and possible rupture of the boiler. This will be prevented by proper selection and installation of a water level control and burner safety controls. The shutoff valve at the pressure reducing valve inlet must be closed except when filling the system, after installation, or after service. Failure to follow these instructions could result in serious personal injury or death and property damage."