Boilers - Steam and Hot Water Systems - Need to add water to hydronic system

50 year old split level house, 3-loop single pump convection baseboard system. No bleeder valves on the convectors. Expansion tank above the boiler seems to be empty. The main valve from the domestic is open. The B&G reducing valve says 12 PSI on the side. Not sure about the valve in front of the B&G (see photo) with the square top... what is this one?

Every winter the amount of gurgling and water trickling sounds in our upper and middle floor convectors increases, and the amount of heat detected in our middle floor convectors decreases. The garden level seems to be OK.
I'm fairly sure we have too much air in the lines. A few years ago we had a heating contractor come out and help refill the system. He did a combination of opening/closing the loop valves while opening the drain valve with the hose on it AND doing something to the reducing valve. I don't remember if he did anything with the valve with the square top on it... I'm trying to do the same thing but don't remember all the steps. I've tried unscrewing the nut and loosing the slotted stem on the top of the B&G reducing valve 1 1/2 turns, but nothing happens. Could the valve be stuck closed? What steps should I follow?
THANK YOU!!!

http://gallery.me.com/medmonds1/100287/Boiler%20pressure/web.jpg?ver=12564873380001

http://gallery.me.com/medmonds1/100287/Manifold/web.jpg?ver=12564873710001

http://gallery.me.com/medmonds1/100287/Supply%20side%20valves/web.jpg?ver=12564872080001

What I can see in the pics:

The square head thingy is probably a 'one way' flow check valve that only allows water into the boiler and not back out into the domestic supply... don't mess with that.

Probably should not have messed with the regulator adjustment... and by turning counter-clockwise, you lowered the pressure setting which is not what you wanted to do.

Thing is, those things either work, or they don't. It's not like they need to be adjusted from year to year. It could well be that it's not feeding any water.

IF your gauge is to be believed (and I would NOT), the pressure reading of appx 12 PSI is very low for a temperature of 200 (which is also suspect) in the boiler.

If the boiler was COLD and it read 12 PSI, then I would say ok, MAYBE the gauge is ok, but I would still verify it. Many techs go 'round'n'round' with pressure problems without verifying that the gauge is telling the truth.

The MINIMUM pressure in your boiler needs to be:

(height in feet from the boiler to the highest point in the system) times 0.432 PLUS 4 PSI.

So, if your height is say 30 feet, then (30 X 0.432) + 4 = 17 PSI.

This is with the boiler COLD (room temp).

Without the minimum pressure in the system, water will not reach the upper radiators...

When the boiler is heated, the pressure will increase, and may be as high as 25 when hot.

First thing to do is verify the pressure gauge.

OK, I wont mess with the one-way valve...

After I turned the reducing valve stem and nothing happened, I turned it back to it's original position. Is that good enough to undo a change in the system that I might have caused?

Regarding the 12 PSI... Thats not what the gauge on the boiler says, thats just what's printed on the outside of the B&G reducing valve. From what I can tell, the boiler is reading that I only have about 5 PSI in the system when its HOT. I'm guessing that sounds really low!

The top of the boiler is no more than about 7 feet lower than the highest point in the system. By your math, that would mean that at a minimum, I should have (7x.432)+4=7.024PSI.

How would I go about verifying the pressure gauge as you suggested? Do I hook up an auxiliary gauge to the valve where the garden hose is attached near the loop manifold and open the valve? If so, does Home Depot/Lowes/Ace have such a gauge?

Thank you so much for your help so far!!!

Oh carp, yer right... 5 PSI ... usually I'M the one that gets to say "Yer reading the wrong scale dummy!" ha ha ... yeah, I was looking at the 'altitude' scale, which is pretty much the formula I posted earlier, except it doesn't take the 4 PSI extra 'headroom' into account.

I should have (7x.432)+4=7.024PSI.

Yes, except that I left out a key component. I should have added: 'or 12 PSI, whichever is higher' . So for your system, 12 PSI cold would be 'proper' even though you might be able to get by with a bit less.

I turned it back to it's original position.

I'm sure it's 'close enough'... it's not a critical number, just needs to be within a couple PSI or so... but:

If the manual feed water valve is open, and you only have 5 PSI in the system, it's a pretty good bet that valve isn't feeding any water... probably defective.


How would I go about verifying the pressure gauge as you suggested?

HD / Lowes / etc, usually carry a gauge that is used by lawn sprinkler folks to check pressures on hose connections. Problem is that the gauge is usually a 150 or 200 PSI job, and the resolution for boiler work is pretty bad. Nice thing about it is the price, around $10 or so. You can't buy individual brass fittings and make your own for that price. If you get one of them, then go to a plumbing supply and pick up a gauge with the same thread, you can remove the gauge it comes with and screw on the other one. A 30 PSI gauge would work great.
OR, if you have a junque boxe to dig into, you could knock one together like this:

http://i224.photobucket.com/albums/dd118/JeffPicks/portable_pressure.jpg?t=1256503600

That's the end of an old warshin' machine hose, and a couple fittings...

BUT, being that your gauge says 5 and not 12, I'm more inclined to think that perhaps the gauge is OK...

I can't tell for sure from the pictures, does your regulator valve have a handle, or a lever on it? Newer ones do, and that handle or lever will 'bypass' the regulator and allow one to fill the system faster.

If your valve is plugged, and there is no bypass on it, then the only way to get water into the system is going to be to have the valve replaced... OR ... to 'backfill' the system using one of the drains. You can hook a garden hose to a drain (you need an adaptor so you can hook up the hose, and an old wash machine hose comes in handy) and SLOWLY! open the drain valve while watching the pressure gauge. If there is a washing machine in the vicinity, you can unscrew the hose from that and hook up the garden hose.

BUT, on older systems, very often when you open a drain that hasn't been opened in ages, you won't be able to get it closed again, and it will drip/drip/drip...

That's the problem with older systems... everything you touch often needs replaced!

You said the expansion tank 'sounds' empty, but you can't really tell by knocking on it. After you get the water into the system, you might find that the relief valve opens because that tank is waterlogged and then have to service that as well.

"It's always something" R.R.

I can't tell for sure from the pictures, does your regulator valve have a handle, or a lever on it? Newer ones do, and that handle or lever will 'bypass' the regulator and allow one to fill the system faster.

No, it doesn't have a lever on it. Its probably fairly old. Can I turn the stem clockwise to force the valve open? (and then turn it back the same amount)

...and SLOWLY! open the drain valve while watching the pressure gauge.


I'm assuming you're talking about the pressure gauge on the boiler itself, since the backfill method would use the same hose connector I would be using for the home-made gauge?

You said the expansion tank 'sounds' empty, but you can't really tell by knocking on it. After you get the water into the system, you might find that the relief valve opens because that tank is waterlogged and then have to service that as well.

Good point. I guess I still think its empty because both the bottom and top of the tank are the same relatively cool temperature, as is the pipe leading up to it from the boiler, where every other pipe is hot.

If I use the backfill method, won't I need to open some location to let the air bleed out? If so, can I use the one on the bottom of the expansion tank OR the little one on the last bend of the return water piping shown in this latest photo?

Thanks again.
http://gallery.me.com/medmonds1/100287/Return%20pipe/web.jpg?ver=12565072960001

Can I turn the stem clockwise to force the valve open?

I doubt it will work. But if it's not letting water in, and needs to be replaced anyway, what's to hurt? If you do see the pressure start to climb and keeps going afterward, close the manual valve.

I'm assuming you're talking about the pressure gauge on the boiler itself

I was... you might find that your old gauge is just fine... you could do like you would when you fill a tire too... put a little in, check the pressure, a little more, check the pressure... or, you could get a hose "Y" adapter and by opening and closing the valves on that measure the pressure with the 'add-on' gauge.

bottom and top of the tank are the same relatively cool temperature, as is the pipe leading up to it from the boiler,

That could actually be an indication that it IS waterlogged. When the tank has the proper air bubble in it, as the system heats up and the water expands, some of that hot water will be pushed into the tank. If you feel cold pipes leading to the tank, it's a good chance that it may be waterlogged.

won't I need to open some location to let the air bleed out?

Hopefully what will happen is that the air that's stuck out in the zones will be pumped back to the boiler and find it's way into the expansion tank, where it belongs. Reality is that it probably won't. I doubt you will get much air out of that small bleeder on top of the boiler, the air has to actually collect there in order to vent it there, and it probably won't (collect there).

We'll talk about that a bit later... cuz I'm 99% sure that the next thing you tell us after getting pressure in the system is that the relief valve is blowing and the pressure is high on the boiler... and then I'm probly gonna tell you that the relief valve should also be replaced... and the expansion tank drained... etc, etc, ...

Follow up!
So I went to my local plumbing supply house and decided to go ahead an buy a replacement Bell and Gossett reducing valve. With this in hand I took your advice and decided that I might as well first try to open the existing valve to try to fill the system. Well, what do you know, after 4 rotations of the stem on the valve, water started to flow, and the pressure gauge on the boiler instantly registered the change. I let in run for about 10 seconds or so, and the pressure reached about 12-13 PSI and I could hear the water going through the valve start to slow down and eventually stop. To me that says the valve works, but was just incorrectly adjusted to stop the flow of new water into the system... Yes?
Now, since there's 18" of new snow on the ground outside right now, I didn't turn off the boiler and let it cool down first, I just turned it off hot. After the procedure I just described, I put my hand up on the expansion tank, and it was hot, and I THINK has water in it. This is normal when the system is hot, right?
Next question...
In order to properly fill and balance the system, do I first need to let it cool down completely and then refill my zones one at a time while trying to hit a target cool pressure of 12 PSI?

Assuming now that my gauges and valves actually function properly, what steps should I start with?

Oh man, 18" of snow! hope you ski!

Thing to watch for: If the pressure on the system begins to s.l.o.w.l.y climb, it's possible that the reducing valve is leaking through now... maybe that is the reason that someone diddled with it? ya never know, but do due diligence and keep yer eye on the pressure. If you see it slowly climbing, you can turn off the manual fill valve.

More important than the cold pressure, what was the pressure when you had the boiler HOT? and at what temp?

It is normal for the tank to get warm/hot... when the hot water expands into it, it HAS to get some temp to it...

Filling the zones? what you need to do is get the air out... I would let it run for a while now and see what happens. With any luck, your expansion tank won't need to be drained, the air in the system will work it's way back into the tank where it belongs, and everything will be fine. With any luck...

I do ski, but not usually in October! Thanksgiving is the earliest I've ever been up to them thar hills.

I will watch the pressure as you suggested...

Before I did anything the pressure while the boiler was hot, was only about 5 PSI. The temperature on the boiler said about 200 degrees. The boiler has been turned off for about 45 minutes and it still says 200... not sure if that gauge is really working.

When I said fill the zones, I mean add enough water so that my pipes don't sound like babbling brookes. I think there are enough up-down spots in the loops that air is getting trapped in the high spots and doesn't get flushed through unless the zone is adequately filled with water... yes?

Shouldn't all the zones be full, with the only air in the system in the tank?

The think I'm not sure I understand is how to properly set the air-water ratio. It seems that I could have 12 PSI on the gauge with too much air and not enough water, or too much water and not enough air. How do I get to the right balance? Thats the million dollar question.

Thanks again!