Hi,

I have a Weil Mclain hot water boiler, Its a model PCG-5 and is 140K btu. This season has been a noisy one. Here goes; As I turn up the thermostat to start the system all is good and quiet for about 3 mins. then the boiler starts to gurgle and make banging noises (not extremely loud but constant). The sound travels through the whole house driving everybody cuckoo. As I would stand next to the unit I can hear the noise coming from the center of the unit. If I touch the (hot) pipes I can feel the vibration. What I have done at the beginning of the season is to replace the water pump (Bell & Gossett), drain spigot, air-release valve (located on top of unit) and pressure-release valve. I did this because I remember the noise from last year and believed this would help some.... it didn't. After replacing the parts I put a garden house at the end of the 'zone' copper pipes, closed all other valves and ran the water until it quit sputtering out any air through the garden hose. I turned it on and the (non pressurized) air tank make a hell of a racket. I turned it all off and played with the valves to fill it up and reran the system. That quieted things with the tank but didn't help one bit with the boiler. FYI, there is only one air bleeder valve in the kitchen that didn't help, I played with the Taco air scoop too but that didn't help. I am at a total loss as to what is making the noise. If it's air (as I've read all over the place here) how the heck do I remove it and how can it be trapped in the boiler itself, as that is where the noise is. I thought I tried everything to remove it. HELP!!! p.s. sorry for the longness of this post.

 

i have been having a similar problem. loud expansion noises coming from the boiler itself. i've put a band aid on it by keeping my cold supply water off, bypasing the auto-fill. this lowers my boiler pressure from 20-22psi to 12-15psi. hope you figure out a better solution and let us know.

 

I'm not seeing a PCG-5 boiler at weil mclains site. Could you confirm that model number. I have a couple of ideas but would like to see the boiler breakdown first.

Ken

 

I have almost the identical problem. As the water in the system heats up a hammering starts at the boiler when the water temp gets to about 165F. High temp limit is set at 180F. Hammering continues until the gas valve shuts off then there is just a couple of small bumps then nothing. When the gas comes back on the hammering doesn't return. It only happens when colder water is in the system. I have good heat in all zones without radiator noise. System pressure is 18psi. Been trying to solve this for the last two years. I replaced the Amtrol Model 109 Fill-Trol unit with a new one as the original lost it's pressure. I discovered this as I was bleeding one of my zones looking for air and I wasn't replacing the water. Thought I cured the problem but it didn't. Noise is driving me nuts.

 

Some boilers have internal thermostatic bypasses. Without the model I have no way of knowing. If you want a better answer, provide the full model number and we can try to move forward.

Ken

 

mine is a Laars-Teledyne D-JVS-125-C. i realized last night that there's water in my ET-60. it didin't earlier this winter but the noise was there, so although i will switch the tank, i think the bladder failing is a symptom, not the root problem. would it help if i took a video (audio, really) of the noise my boiler is making when it fires? does photobucket support video?
thanks

 

hull, yes you can post videos on photobucket...

I wanted to get around to talking about that bypass valve on your boiler, but I don't want to hijack mr mogways thread, so I'm gonna gonna PM ya about it...

[edit for future readers: fromhull's noise problem was solved by opening the {closed} system bypass valve slightly (thankfully, the installers read the install instructions, and included the valve recommended by the manufacturer.), allowing more flow through the boiler. Noise stopped instantly. His is a copper tube boiler and this probably wouldn't be a solution for a cast iron boiler]

 

I have a Utica Model #150AGB, Naturel gas, 150000BTU. 24 years old. Thanks.

 

Hi again,

The model is a PCG-5, I was able to DL the instruction and installation manual on the Weil Mclain website which confirms it. Nothing has changed, good or bad. Still noisy and has the same symptoms as I originally posted. A member, fromhull noted that the cold water auto fill might be the culprit but I don't think it is as mine is a closed system and should rarely need to be refilled. The way it is water would have to be leaking somewhere for it to have the need to refill that much. My latest guess is that maybe there's some sort of buildup in the chamber. I'm going to try to flush the unit with a strong stream of water. I don't know if that is a good idea but hopefully I'll purge any buildup that is there. I am still hoping to get some help here on this. Warmer weather means I can dig deeper into the problem and I'm not afraid to get my hands dirty.

 

mrmogway, can you post a link to the site that you found your boiler info ?

What is the system pressure when the boiler is cool ? when hot ?

How old is your boiler ?

What type of heat emitters are connected ? ( fin-tube baseboard, standing cast iron radiators, etc ? )

I suggest that you set up a free account on www.photobucket.com and upload a whole bunch of pics of the boiler and associated piping. By looking at the photos, we may be able to advise which valves to open, close, etc in order to properly flush the system...

Keep in mind that in general, it is not advisable to flush out a hot water system. Fresh water contains oxygen which will cause rusting of the system components. Once all the o2 is driven out of the water, it becomes basically inert...

But, if your problem is indeed sediment in the boiler it will be necessary ...

So let's have a look see what ya got .

 

Hi,
Thanks! I wasn't sure if it is o.k. to post a link. The first link is for the installation: http://www.weil-mclain.com/downloads...gcginstall.pdf

And here is the operation instruction:
http://www.weil-mclain.com/downloads...goperating.pdf

The continuous pressure is 12lbs and stays there running or not.
The age of the boiler is roughly 25 years +- 5.
It feeds fin-tube baseboard.
I do understand the fact of replacing inert water with oxygenated and the corrosion it could create. I honestly believe I was the only one who has ever drained it. I had to in order to replace all those parts. I will do as you suggested and post a bunch of pics on photobucket. One thought... when I did drain it (12/2007) I don't recall seeing much of any kind of sediment coming out. I remember thinking how odd it was that not much of anything but water came out. Until I get those pics up at least you can pursue the paperwork from Weil McLain. Thank you!

 

I also am including a link to a complete parts list/diagram for this series.
http://www.weil-mclain.com/professio...tinued/cgd.pdf

 

I have the same "banging" issue with my Weil-McLain P-CG 6 series 4 boiler. Wondering if/how you solved the issue?

 

I have a Weil McLain 140k BTU Boiler,. hot water return with the exact same problem, and I have just about replaced all parts just as the first poster, some parts more than once already.

Any updates?

 

sounds like you have air trapped in the top of the sections so every time the boiler fires your making steam and thus a banging noise, are the pumps pumping away from the boiler or into the boiler. if away is the relief valve located on the top side of the boiler thus you can vent the air