How do I drain the water in my gas boiler?

zuffy · 11-04-07, 07:54 AM

I know Thor started a thread on draining his water heater but I need some help. Don't wanna burn myself or screw myself with no heat with the winter here in NYC. I bought this house only a few months ago and the owner didn't say anything or left manual for the boiler. It's a Weil McLain EG-40 or EG-45 gas boiler. I downloaded the manual from their site but it's more meant for a plumper that'll understands it.

There is a low water cut off relay. Is the valve below my drain hole?

I think this water gauge is the water level for the boiler. The water is clear now but when it's running, I can see some brown residues in it. Anyone know what are the top and bottom knots are for? And what is that big pipe for?

OK, I think the PSI gauge is my stream pressure but what is that open valve at the top.. the stream release valve?

I guess this controls the stream release?

I am assuming this is where the water is feeding the boiler

DarthVong · 11-04-07, 10:07 AM

Shut of the water supply (last pic). Turn off the power to it so you don't burn up the heating element/s. Attach hose to the spigot (2nd pic), open pressure valve (4th pic). Once you do that just open of the valve on the spigot.

I have no idea what that big pipe (3rd pic) is for. It seems to large to be a blow off or drain line.

If you want to flush it out. Then once the tank is drained, open your supply valve (last pic) water will fill into bottom of tank and then go out the spigot.

zuffy · 11-04-07, 12:03 PM

Thanks Darthvong. While I was googling the internet for help, some places say no need to drain the water because the ones inside the boiler are treated. If I were to flush out the out, the new untreated water can shorten the life of the boiler. Is this true?

Nick Danger · 11-04-07, 12:25 PM

That's an overpressure relief valve in picture 4. It makes me a little nervous. It's supposed to be piped to within eight inches of the floor, or outdoors. The way it's set up now, if the valve opens, someone is going to be sprayed in the face with boiling water.

The reason there are valves above and below the water level gauge in picture 3 is so you can turn off the water when it breaks and you have to replace it.

Boilingman · 11-04-07, 06:39 PM

In addition to what Dartvong said I'd turn off the gas as well just to be on the safe side. It shouldn't fire when the power is off but you can never be too safe when working with boilers. Since the water level is below the big blowoff valve if it was me I'd put a bucket under the pipe and open that to let air into to drain it instead of the safety valve. If you use the safety valve it may not reseat since I really doubt it has ever been tested.

The big valve in picture 3 is a surface blowdown valve. It allows you to remove anything contaminants floating in or on top of the water.

The Honeywell control in picture 5 is a limit control. It controls the steam pressure at the proper operating pressure when there is a demand for heat call from the thermostat(s).

I agree that safety valve w/o piping is more than alarming. It needs to be properly piped ASAP!

I'd check the manufacturers recommendation for treating the boiler. Depending on the treatment used it can cause more problems than it solves, especially if the system has never been treated. It all depends on what you local water is like is to how fast it'll wear out. It also depends on how often its drained and refilled. Too much draining and refilling will cause damage because you introduce not only more scale causing minerals but also oxygen which will cause corrosion. Once it's filled you shouldn't need to add much water unless you have a leak or defective air vent somewhere.

The brown color when its running is rust and/or dirt from the condensate return and some scale from inside the boiler itself.

zuffy · 11-04-07, 08:34 PM

Awesome Boilingman. I am going to get the proper pipes for the safety valve and point it below where the big pipe pointing.

zuffy · 12-08-07, 04:03 PM

Just an update. Since I got my water heater replaced today and it's actually warm compare to the previous few days, I've decided to drain the boiler. I drain it until the water is no longer brown and it was quite brown. Next, I open the blowdown valve, HOLY SHIT, a couple of inches of black shit came out. I manage to get a user manuel from Weil McLain and in it, it explain how to clear the glass gauge. Holy shit there too, except it was not as black and as much.

Thor Simpson · 12-08-07, 05:04 PM

This is why I refuse to live in a train engine.

Nick Danger · 12-09-07, 11:26 AM

Did you repipe that pressure relief valve?

zuffy · 12-09-07, 01:30 PM

Yes I did.

Thor Simpson · 12-09-07, 03:39 PM

Quote:

Originally Posted by zuffy

Yes I did.

You are a stud.

God bless Dvdtalk where people spot things like this. Great job, Nick Danger.

11-04-07, 07:54 AM	#1
zuffy DVD Talk Legend Join Date: Jan 2000 Location: Region 1 Posts: 16,136	How do I drain the water in my gas boiler? I know Thor started a thread on draining his water heater but I need some help. Don't wanna burn myself or screw myself with no heat with the winter here in NYC. I bought this house only a few months ago and the owner didn't say anything or left manual for the boiler. It's a Weil McLain EG-40 or EG-45 gas boiler. I downloaded the manual from their site but it's more meant for a plumper that'll understands it. There is a low water cut off relay. Is the valve below my drain hole? I think this water gauge is the water level for the boiler. The water is clear now but when it's running, I can see some brown residues in it. Anyone know what are the top and bottom knots are for? And what is that big pipe for? OK, I think the PSI gauge is my stream pressure but what is that open valve at the top.. the stream release valve? I guess this controls the stream release? I am assuming this is where the water is feeding the boiler

11-04-07, 10:07 AM	#2
DarthVong DVD Talk Limited Edition Join Date: Jul 2002 Location: Under your bed Posts: 5,665	Shut of the water supply (last pic). Turn off the power to it so you don't burn up the heating element/s. Attach hose to the spigot (2nd pic), open pressure valve (4th pic). Once you do that just open of the valve on the spigot. I have no idea what that big pipe (3rd pic) is for. It seems to large to be a blow off or drain line. If you want to flush it out. Then once the tank is drained, open your supply valve (last pic) water will fill into bottom of tank and then go out the spigot. __________________ PSN: DARTHVONG XBOX: The Darthvong

11-04-07, 12:25 PM	#4
Nick Danger DVD Talk Legend Join Date: Mar 2001 Location: Albuquerque Posts: 14,517	That's an overpressure relief valve in picture 4. It makes me a little nervous. It's supposed to be piped to within eight inches of the floor, or outdoors. The way it's set up now, if the valve opens, someone is going to be sprayed in the face with boiling water. The reason there are valves above and below the water level gauge in picture 3 is so you can turn off the water when it breaks and you have to replace it. __________________ Originally Posted by TallGuyMe: hoorah for Nick! Last edited by Nick Danger; 11-04-07 at 12:33 PM.

11-04-07, 06:39 PM	#5
Boilingman Member Join Date: Feb 2004 Location: A little place I like to call you'll see Posts: 64	In addition to what Dartvong said I'd turn off the gas as well just to be on the safe side. It shouldn't fire when the power is off but you can never be too safe when working with boilers. Since the water level is below the big blowoff valve if it was me I'd put a bucket under the pipe and open that to let air into to drain it instead of the safety valve. If you use the safety valve it may not reseat since I really doubt it has ever been tested. The big valve in picture 3 is a surface blowdown valve. It allows you to remove anything contaminants floating in or on top of the water. The Honeywell control in picture 5 is a limit control. It controls the steam pressure at the proper operating pressure when there is a demand for heat call from the thermostat(s). I agree that safety valve w/o piping is more than alarming. It needs to be properly piped ASAP! I'd check the manufacturers recommendation for treating the boiler. Depending on the treatment used it can cause more problems than it solves, especially if the system has never been treated. It all depends on what you local water is like is to how fast it'll wear out. It also depends on how often its drained and refilled. Too much draining and refilling will cause damage because you introduce not only more scale causing minerals but also oxygen which will cause corrosion. Once it's filled you shouldn't need to add much water unless you have a leak or defective air vent somewhere. The brown color when its running is rust and/or dirt from the condensate return and some scale from inside the boiler itself. Last edited by Boilingman; 11-04-07 at 08:26 PM.

12-08-07, 05:04 PM	#8
Thor Simpson DVD Talk Hero Join Date: Apr 1999 Location: Seattle, WA Posts: 35,043	This is why I refuse to live in a train engine. __________________ I'm not a fan of people quoting others and saying "This," but... This. - VinVega

11-04-07, 12:03 PM	#3
zuffy DVD Talk Legend Join Date: Jan 2000 Location: Region 1 Posts: 16,136	Thanks Darthvong. While I was googling the internet for help, some places say no need to drain the water because the ones inside the boiler are treated. If I were to flush out the out, the new untreated water can shorten the life of the boiler. Is this true?

11-04-07, 08:34 PM	#6
zuffy DVD Talk Legend Join Date: Jan 2000 Location: Region 1 Posts: 16,136	Awesome Boilingman. I am going to get the proper pipes for the safety valve and point it below where the big pipe pointing.

12-08-07, 04:03 PM	#7
zuffy DVD Talk Legend Join Date: Jan 2000 Location: Region 1 Posts: 16,136	Just an update. Since I got my water heater replaced today and it's actually warm compare to the previous few days, I've decided to drain the boiler. I drain it until the water is no longer brown and it was quite brown. Next, I open the blowdown valve, HOLY SHIT, a couple of inches of black shit came out. I manage to get a user manuel from Weil McLain and in it, it explain how to clear the glass gauge. Holy shit there too, except it was not as black and as much.

12-09-07, 11:26 AM	#9
Nick Danger DVD Talk Legend Join Date: Mar 2001 Location: Albuquerque Posts: 14,517	Did you repipe that pressure relief valve? __________________ Originally Posted by TallGuyMe: hoorah for Nick!

12-09-07, 01:30 PM	#10
zuffy DVD Talk Legend Join Date: Jan 2000 Location: Region 1 Posts: 16,136	Yes I did.