pressure issue


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Old 03-18-08, 03:11 PM
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pressure issue

Hey all,

I just moved into a new home with a Weil-McLain CG series boiler. The pressure is reading low and the system does not seem to be producing heat effectively on the upper floor. There is an automatic fill valve that should be filling the system to 12 psi, but it is steady at 5 psi Any suggestions?
 
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Old 03-18-08, 03:18 PM
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jr, is there a manual shut-off valve on the line in addition to the automatic one ? Is it open ?

Which brand fill valve do you have ?

Set up a free account on www.photobucket.com and upload many pictures of the boiler and associated piping there. Provide a line here for us to view. Helps to see what we're working on ...
 
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Old 03-18-08, 04:54 PM
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Here are the pics. You can see the expansion tank in the upper corner of the first shot. The fill water comes straight off a T junction from the main water line, thru one shutoff, the check valve, pressure reducing valve, and then another shutoff valve to the boiler return pipe.

Overview of system


View of flow regulating valve, reducing valve and SOV


Closeup of reducing valve
 
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Old 03-18-08, 04:57 PM
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Originally Posted by NJ Trooper View Post
jr, is there a manual shut-off valve on the line in addition to the automatic one ? Is it open ?
Both SOV's appear to be open

Originally Posted by NJ Trooper View Post
Which brand fill valve do you have ?
Bell and Gossett FB-38 set at 12 psi. Does that screw on the top of the bell allow pressure adjustment?

I've seen the term 'waterlogging' the expansion tank in my research here. I moved the tank and there does seem to be some water in there. Should I drain it?
 
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Old 03-18-08, 05:09 PM
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another pic

 
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Old 03-18-08, 06:19 PM
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Yes, the valve is adjustable, but don't do that yet. First, see if you can get water through it... watch the pressure gauge and lift up on the 'fast fill handle'. That handle bypasses the regulator in the fill valve and allows water to go through at city pressure. If the boiler is HOT, turn it off and WAIT until it cools to 100░ or so. Never introduce large amounts of cold water into a hot boiler... C R A C K ! ... you don't want that.

If you do get water in, hold the handle until you are reading 12 PSI on the gauge.

Fire the boiler and watch the pressure gauge, it should increase maybe as much as 8-10 PSI from cool to hot... if it doesn't go higher than that, no need to do anything with the expansion tank at this time.

Expansion tank only controls the _increase_ in pressure when the boiler heats up by giving the expanding water someplace to go ...

There will always be some water in the expansion tank. Probably as much as 2/3 full under normal conditions. The problems come when that 1/3 that should be air is water. That's what a 'waterlogged' tank is, one that has no air cushion trapped at the top.

Are there air bleeders on the radiators ?
 
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Old 03-18-08, 06:25 PM
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I'm always suspicious of the accuracy of the pressure gauge.

I use this to verify the gauge, made from an old washing machine hose and a gauge with a few fittings to adapt. HD and Lowes sell gauges that screw onto a hose spigot to check pressure, but they are usually 0-200 PSI and pretty useless for the pressures in a boiler, but they will work. They go for around $10 or so ...

 
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Old 03-18-08, 06:36 PM
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If the auto fill valve isn't passing any water, you can try cleaning the strainer screen located in the bottom.

Here's the PDF file for your valve, instructions are there...

Bell & Gossett reducing valve PDF

Since you have shut-off valves on both sides of the reducing valve, job is easier ...
 
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Old 03-18-08, 06:48 PM
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I lifted the fast fill handle and there was no change in pressure, no audible water flow, nothing.

I found a manual for the reducing valve here. I removed the strainer on the bottom to check for a clog and there was none. As a precaution, I opened the SOV while the strainer cap was off to flush any debris out of the valve and I only got a very slight trickle of water. I don't think that's normal, but I don't have any way to know for sure.

As mentioned, the water line comes off a T-junction just before the water enters the hot water heater. I am having no issues with the hot water system, so I know there is water pressure up to that point. I appears there is a supply issue somewhere in the cold water flow.

I don't have a bypass, so is there another way I can boost up the pressure until I can get the supply issues worked out?

I haven't checked the pressure using a different gauge, so I'll give that a try before I get too far down the path.
 
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Old 03-18-08, 06:52 PM
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Originally Posted by NJ Trooper View Post
If the auto fill valve isn't passing any water, you can try cleaning the strainer screen located in the bottom.

Here's the PDF file for your valve, instructions are there...

Bell & Gossett reducing valve PDF

Since you have shut-off valves on both sides of the reducing valve, job is easier ...
you're a faster typer than I am...LOL
 
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Old 03-18-08, 07:03 PM
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you're a faster typer than I am...LOL
But I bet yer a better shot with the bow than I am !
(nice buck!)

Try giving that check valve a smart 'RAP' and see what happens. It might be stucked... don't wail on it though ...

Is there a washing machine in the vicinity ?

You can remove one of the hoses from the back and create a 'cross connection' from there to a boiler drain to fill the boiler. If the boiler is hot, use the hot water connection.

There's a drain valve on the expansion tank, yes ? If so, hook the hose to that rather than the boiler drain, and don't bother 'leaking' the air out of the hose as stated below. A little extra air in the tank won't hurt a thing.

Hook a garden hose to the boiler drain, and the other end to the hose that you removed from the washer. Open the valve at the washer, but don't open the boiler drain yet. Crack the hose connection at the boiler loose so that the hose 'leaks' the trapped air. You don't want the air in the hose going into the boiler. When water starts coming out the 'leak', tighten the hose and SLOWLY!!! open the boiler drain. Watch the gauge carefully and close when the pressure gets to 12 PSI . Don't disconnect the hose yet.

If you have bleeders on the radiators, go up and see if you get air out of them. Get as much air out as you can and go back and check the pressure in the boiler again. It may be lower because of bleeding the air. If so, top it off and remove the hose.

let us know how you do...
 
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Old 03-19-08, 05:38 AM
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I gave a stuck gate valve a smart RAP once, it was fun, got a whole 2" of water in the basement before the firemen and police could locate the water company after hours for me. It was the watermain to the house. Wifey was pissed.

Any way, that looks like a union to the left of that reducer. Maybe you can take the reducer off, open that ballvalve, and see if it pees? Maybe there is a big piece of rust or something stuck in the opening to the reducer.
 
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Old 03-19-08, 06:05 AM
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I wish that were my buck! My cousin always gets the good ones.

I took your advice and gave the check valve a few light taps to see if I could shake it loose. On the third tap, water started moving and the pressure came up.

I bled all the radiators and I'll do it again in a few days to get the dissolved air out.

One last question. Should I leave the SOV from the reducer valve open in normal operation? Unless I spring a leak somewhere, I don't imagine that it would introduce enough cold water to damage the boiler.

This is my first home with radiator heat, so it's a bit of a learning process for me. Thanks a ton for all your help.
 
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Old 03-19-08, 02:51 PM
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The big debate about whether to leave the make-up valve open or closed revolves around whether or not there is a LWCO (Low Water Cut Off) installed on the boiler.

I didn't see one in your pics... so,

If you close it, and run low on water, you run the risk of dry firing the boiler. Damage to the boiler will result, and the risk of a fire starting is greatly increased.

If you leave it open, and you spring a leak, chances are you'll have some water damage.

Given the two options, I would leave it open, and do due diligence in keeping an eye on the system...

B&G's literature recommends closing the valve, but they do also include the caveat about the LWCO.

You might consider adding an LWCO at some time in the future.

Where do I sign up for my flying lessons ?
:mask:
 
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Old 03-20-08, 05:44 AM
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Okay, I'll look into adding a LWCO since it sounds like the only way to really minimize the risk of boiler damage and/or flooding. I'll keep the fill valve open for now and keep an eye on things.

As I was bleeding all the radiators after adding all that new water, I noticed a few radiator supply valves that probably need to be replaced this summer. In fact, one of the valve stems feels like it is completely sheared and was seeping a little water. I tie wrapped it so that it cannot pop out, just in case, and used some epoxy putty to seal the leak for now. Any recommendations on brands to use for replacement?

I'm in Southern Ohio, so if you're this way, shoot me a message and we'll do some flying.
 
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Old 03-20-08, 04:51 PM
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jr, can you snap a few pics of the radiator valves ? (maybe a little bigger for old eyes to see better ?)

That valve that seems to be sheared... does the handle just turn and turn and turn ?

There may be a 'packing nut' below that handle that can be tightened, or perhaps replacing the packing, will probably stop the leak, IF it's not sheared.

I rarely go 'west'... but if I do, count on a shout! and even if we don't go flying, we can hoist a few brews...
 
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Old 03-21-08, 10:21 AM
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I'm out of town, so I'll get some pics when I get home next week. The valve that seems sheared does just turn forever with very little resistance. All the other valves are pretty tight, as they are likely original to the house from the late 30's.

The valves look similar to this..
 
 

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