Crown Boiler AWI095 loses water pressure

Gregory_2

I have an existing crown boiler that loses pressure
Its very close to zero then when system turns on goes up to between 5-10psi but very shortly drops back down close to 0. I add water and pressure comes up to 15+ but within a day or so its back down to 0.
I have a pressure reglator coming from the supply and an expansion tank bladder style. I checked the pressure in the tank and its right at 12ish psi. I am not and have not seen any water leaking any where and no relief valve discharge....
a few questions
1. do I need to turn off supply to check exp tank
2. I do have a auto bleeder at "top" of the run

please help
TIA gbbw71@aol.com

Jamie Hall

On 1 -- no, all you need to do is check the air pressure at the Scharder valve. If you have good pressure -- and no water comes out! -- you should be good on that (poor pressure -- or water comes out -- may indicate an expansion tank problem).

On 2 -- shouldn't be a problem.

All that said -- the combination of an pressure regulator and low cold pressure can only mean that the pressure regulator isn't regulating the pressure. Try manually running the pressure up to 12 psi with the system cold, and then closing any available manual feed valve. If the pressure still drops, you have a leak somewhere (it might be in the boiler -- it's more likely somewhere else).

You may be able to isolate the leak to the boiler or sections of the system by bringing it up to pressure and then isolating the boiler or sections of the system. If you can do that, do.

Gregory_2

understood thank you.
I have pretty high supply pressure coming in so I assumed even if the pressure regulator was bad it wouldnt bleed back? altho I am now noticing a small wet area at the connection of the regulator. another question if I may...on the supply side I have valve then pressure regulator all copper line then on the other side of regulator to the expansion valve and into the unit is black metal and it looks corroded in at the elbows and ends. Is the black metal ok for that application? thanks again

Jamie Hall

Black iron is fine. Galvanized steel, not so much. Copper is fine. Corrosion, though -- if it really is -- may indicate a pinhole leak or just weeping at the threads. That does happen.

That wet area at the connection of the regulator -- is it on the system side? If it is, that could account for at least some of the pressure drop -- though not likely all of it.

Do try the test of bringing the system up to operating pressure and closing it off as completely as you can and watching what happens. If you can valve off the expansion tank so much the better -- even a small leak will show up as a quick pressure drop.

STEVEusaPA

You do need to isolate the bladder type expansion tank from the system, or drop the system to 0 to check the charge on the tank.

Gregory_2

I took pressure up to 10psi, shut off supply, then let it turn on when temp hit 140 the pressure was up around 20, when temp got to 180 pressure was about 22.... I'll check pressure again in an hour after it cools.
do these numbers sound right
if pressure leaks down to 0 I will check bladder pressure again thank you

Gregory_2

Temp down to 120 and pressure at approx 13 psi
someone in my house decided to turn the heater on while I was obviously working on it (or more accurately watching it)

Gregory_2

100 degrees and 10psi

STEVEusaPA

If the tank is properly sized and working, system pressure matches expansion tank pressure, and your system is purged of all air, the pressure should barely change.

JUGHNE

Well, it is about time to ask for pictures......

With 0 PSI on your gauge your tank should be empty, sound empty when you ring it. And feel empty when you move it a little. Then it should have at least 12 PSI in it....add if needed.

Can you see where all the piping goes? You could have a pinhole in copper somewhere, if so you want to find it before it finds you.

But pictures are good. Back up enough so we see all the piping at the boiler....all sides.

Gregory_2

I can’t see all the pipe but it’s been an ongoing thing so I believe a leak would have found me by now. And yes the tank felt empty and showed 12psi.
See pics
The gauge is against the wall a bit so it’s hard to get a reading but I usually just take a pick with my phone.
So you are saying when the temp changes the pressure at the gauge shouldn’t change that much.?

Gregory_2

Over a 2.5 hr span roughly from 0 psi then added water to 10psi then turned on unit
140 degrees at 20psi
180 degrees at 22pso

JUGHNE

When the temp rises the pressure would also rise.....depends upon how much air cushion is available.
But when cooling off it should not drop to 0 PSI.
Has that been the size of exp tank that has always been there before you had any problems?

Gregory_2

Yes same tank.

Gregory_2

Still holding at 100 degrees and 10psi
And a few pics

Gregory_2

Still holding at 10psi at 90degress. Will update in the am. Thanks all.

Gregory_2

Seems to be holding. Waiting for a total cool down

Thanks everyone. Only difference is I shut off supply

Gregory_2

Ok still at 10psi and 70 degrees
any thoughts on how / why shutting off supply would stop it from losing pressure? the pressure regulator WATTS S1156F should hold back pressure ? or at worst the supply pressure is greater than the regulator pressure?

JUGHNE

PRV's do not work well as a back flow preventer.
But with only 12 on the boiler side and your city pressure on the other it does not seem possible that your boiler water could go back to your house supply.

However it happened to me, the 6" city main out front had to be drained and it siphoned the water out of my boiler to drop the pressure to 0 PSI. I have since then added a BFP and also have a low water cut off to prevent operating the boiler dry. I now also leave the feed water off.

Is there some major usage of water on the line that supplies the boiler PRV? With marginal pressure in the house it is possible that the water back flowed......very slim chance but possible.
I am just assuming you have maybe 60 PSI water in your house.

In any event you should have a BFP device on your boiler feed.
A LWCO is good insurance also.

Gregory_2

At least 60 from the street.
and yes hot water heater is on same feed
thank you
Is LWCO redundant or no? I assumed boiler would already have
it. so Back Flow Preventer and Low Water Cut Off will fix me up

JUGHNE

For now I would leave the water off and but check twice daily.

LWCO's are not usually installed at the factory.

Your boiler may not be out of the woods yet as far as leaking goes.

Gregory_2

Stay at 10psi or up it to like 12 or 15 and shut off supply
3 story brick rowhome in philly

thanks for your help

Gregory_2

Also is 22 psi ok at 180degees

Jamie Hall

Gregory_2 said:

Also is 22 psi ok at 180degees

Well... it's livable with. It's not really OK -- but it's not cause for immediate concern, either. What it does suggest is that the expansion tank is smaller than it should be (and probably always has been!). But it's not something I'd fuss over -- or try to fix -- in any great hurry.

Gregory_2

Again today 10psi at 70 degrees
And 22 at 180 degrees

Gregory_2

Same today.
Here is a pic of the expansion tank. Do you think I should upgrade ?

Gregory_2

Not sure if this came thru last post

Jamie Hall

That's cute. Chances are that it's way too small. Amtrol has a nifty selection tool here: https://www.amtrol.com/resources-rewards/selection-tools/ which is kind of a no-brainer to use. But works.

Gregory_2

according to the link I'm about half of what is ideal. thank you.

Gregory_2

Seems to be still losing pressure. Its now down around 8 psi
would air in the line affect this?

Jamie Hall

Gregory_2 said:

Seems to be still losing pressure. Its now down around 8 psi
would air in the line affect this?

no. You have leak -- a small one -- somewhere.

EdTheHeaterMan

Cast iron radiators? Packing nuts on the rad valves are letting air out and letting air in. Especially on the third floor. I'm guessing at the measurements of the hight of the radiators from the boiler.
Assumptions:
#1 Boiler in basement
#2 Top of radiator on the first floor is 10 ft above the boiler gauge
#3 Top of radiator on the first floor is 20 ft above the boiler gauge
#4 Top of radiator on the first floor is 30 ft above the boiler gauge
#5 Cast iron radiators

Static pressure:
A. Is the pressure of the water in the boiler,
B. It is a measurement of the weight of the water above the gauge.
C. It is the pressure needed to get the water to the highest point in the system.
D. it has nothing to do with the Head Pressure of the circulator pump.

Diagram illustrates actual static pressure in the system at different points of elevation.



At 20 PSI in basement you have enough pressure to fill the system with 5 PSI to spare

At 10 PSI in the basement, any pipes on the third floor will at a pressure less than atmospheric pressure commonly referred to as a vacuum. This lower pressure (or vacuum) in the third floor radiators and piping will allow any air vent to let air into the system. (picture in your minds eye an inverted glass in the kitchen sink full of water) Now lift the inverted glass out of the water and the water stays in the glass until you break the vacuum by lifting the edge above the water surface.

As long as the top radiators have no air leaks the water is staying in there. Enter a vacuum breaker into the equation, like an automatic air vent or a loose packing nut on a radiator valve, and you have a leak that will let air in an mess with your mind about the water pressure on the boiler gauge.

When the boiler gauge drops to 0 PSI in the basement, there is a deep vacuum on the third floor radiators. Up to 12" Hg. or more up there on the 3rd floor. Take into consideration the leak is so small that the water evaporates from the high radiator temperature, you never see the water on the floor!

A.To solve the problem purchase the proper size expansion tank.
B.Add air pressure to the tank to 15 PSI
C.Install the tank on your system.
(BTW the threads on the #30 or #60 tank should be on the top. after you take the #15 tank off turn the 90° elbow 180° to point down)
D.Fill and vent all the radiators starting at the first floor, then the second floor then the third floor.
E.Fill the boiler (cold) to 15 PSI on the gauge.
F. Start boiler and see the gauge move very thru the temperature range 70° thru 180°

EdTheHeaterMan

Type O

F. Start the boiler and watch the pressure gauge mover very LITTLE thru the temperature range for 70° to 180°

Gregory_2

EdTheHeaterMan
assumptions
1. correct boiler is in basement
2. not radiators baseboard with fins
but your measurements are pretty close

also have (2) kick space heaters 1. is under kitchen cabinet
and is basically a small radiator with a fan and 2. the other one is installed in the floor same deal a small radiator with a fan.
there are bleed valves on both.
also on 3rd floor have an auto bleeder (see pic of similar in next post)
Constantly have air in 3rd floor pipes...sounds like a tidal wave at times. even after bleeding system it always seems to end up with air. I serisouly thought thought that the auto bleeder was letting air in instead of letting air out

when we installed/replaced the unit....a licensed HVAC master tech etc etc
did the install I just helped ( he passed away a few years back) we had problems getting air out. I was told by the Philadelphia Gas Works guy that there is another bleeder valve somewhere in the basement that was covered by finished drywall but I looked at my neighbors open ceiling and couldnt find it. PGW guy told me that the system was built wrong on all the houses in my neighborhood. he said instead of a loop its a loop in basment and a leg to 1st floor then a loop then a leg to 2nd floor loop so its not as easy to get rid of air pockets?
thanks for your help

lmk what your thought are

Gregory_2

This is pretty much same thing I have on 3rd floor

Gregory_2

Also this

JUGHNE

If you have some air trapped in the system and it does leak out somehow that will drop the pressure in the system.
As you bleed air out of the higher radiation the PRV should add water to raise the pressure.
Now if some air travels to a point where it can leak out on it's own the pressure will drop.
It you get the PRV adjusted to the right pressure and leave it on that air may vent itself.
Air will leak out where water will not......it is thinner.

If you get rid of any excess air then your tank could be too small,
meaning the pressure may rise too much as temp rises.

Gregory_2

Does the fact that this is sideways instead of up and down have any bearinf

Gregory_2

Been checking the gauge and its holding at 10 psi. only change I made is I tightened the valve cap on the auto bleeder. supply water is still turned off. Any input would be appreciated TIA

Gregory_2

but its still gurgling pretty bad

Gregory_2

So is it possible that over the summer the pressure dropped since I don’t have a back flow preventer and drained a little of the water. And when I first started it up this winter the auto bleeder was taking some of the pressure out Making it look like a leak. So once I get it up to good pressure with no air (or less air) it should be good.
As of now it’s holding at 10psi for last few weeks with supply turned off and auto bleeder valve closed. TIA