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-   -   Steam heat Boiler burns, steam doesn't travel? (http://www.diychatroom.com/f17/steam-heat-boiler-burns-steam-doesnt-travel-83823/)

tomhere 10-13-2010 12:27 PM

Steam heat Boiler burns, steam doesn't travel?
 
During the summer, my old house was installed with new hardwood floors. All the radiators were removed and reinstalled afterward. I also changed the old thermostat(has Hg) to a new Honeywell programming thermostat(for Heat only). According to the manual, I only connected the Y and R wires to the new thermostat and disconnected the other two C wires.

The problems are:
1. The gas knot is set in ON position. After I set the Thermo temp above the room temp, and turn on the main electricity switch, I can hear a click from the boiler and the circulator starts rotating, the boiler doesn't burn automatically. I Tried to light the boiler, but there is no gas coming out, both the burning section and the pilot lighting tip.

2. I can light the burner with the Pilot function. After it's lit, the burner starts burning after I turn on the main electricity switch. Once the temperature reaches ~180F in the gauge(preset), it stops burning and I only can very hot by touching the pipe within a very short distance from the burning. No heat in upper part of the pipe (~4 feet) or radiators. I released gas from the radiator vents until there is water coming out. Is that too much water in the pipes/radiators that preventing the steam from traveling around?

The steam boiler is Weil-Mclain PCG7, anyone knows the age?

The heat was working in last season.

Thanks a lot!

AllanJ 10-13-2010 01:10 PM

Is this a steam system as opposed to a forced hot water system?

There should never be so much water accumulated in a steam radiator that it pours out when you open the valve.

The "air valve" on a steam radiator is supposed to open by itself and remain open until the radiator is full of steam, then close by itself. The radiator will not actually fill with steam at first but it should get good and hot as steam coming up from the boiler condenses on the inside.

If the air valve does not open by itself then steam will not come up into the radiator. The steam is not at a really high pressure and has to push some of the air inside the radiator out the air valve.

Check the water level gauge on the boiler for the proper level, generally around 2/3 full when the boiler has been off for awhile.

tomhere 10-13-2010 01:42 PM

Quote:

Originally Posted by AllanJ (Post 516210)
Is this a steam system as opposed to a forced hot water system?

There should never be so much water accumulated in a steam radiator that it pours out when you open the valve.

The "air valve" on a steam radiator is supposed to open by itself and remain open until the radiator is full of steam, then close by itself. The radiator will not actually fill with steam at first but it should get good and hot as steam coming up from the boiler condenses on the inside.

If the air valve does not open by itself then steam will not come up into the radiator. The steam is not at a really high pressure and has to push some of the air inside the radiator out the air valve.

Check the water level gauge on the boiler for the proper level, generally around 2/3 full when the boiler has been off for awhile.


Thanks for the quick reply! we bought the old house early this year and I am really a newbie. The strange thing is that none of the radiator has air valve attached. It only has an air vent which remains closed all the time (I guess, I will take a pic of it). I can use the little radiator air vent opener to open or close it. When I opened it for the first time, I heard air coming out until water.

Another thing about the boiler is that it doesn't have the water level gauge as everyone says on the web. I believe it's a steam system. Here is the boiler's installation Doc (or 97% close). it's too big to attach here:

http://www.weil-mclain.com/en/multim...gm7install.pdf

beenthere 10-13-2010 07:46 PM

I really hope its not a steam system. Cause if it is. Your going to have really loud pipes for a while. Since steam boilers aren't suppose to have water in the rads.

Since it does have a sight gauge. Its probably a hot water boiler.

If it has a flow check. it could be that the flow check is stuck closed. Post pics of the boiler, and the piping near it.

tomhere 10-13-2010 11:01 PM

6 Attachment(s)
Quote:

Originally Posted by beenthere (Post 516372)
I really hope its not a steam system. Cause if it is. Your going to have really loud pipes for a while. Since steam boilers aren't suppose to have water in the rads.

Since it does have a sight gauge. Its probably a hot water boiler.

If it has a flow check. it could be that the flow check is stuck closed. Post pics of the boiler, and the piping near it.

I thought it's a steam boiler, and according to the menu, there should be water coming out from the radiator. Maybe I was doing something wrong. Please see the pictures...

beenthere 10-13-2010 11:06 PM

You have a water boiler. Make sure your circulator is working. And that the valve above the circ is open.

tomhere 10-13-2010 11:46 PM

Quote:

Originally Posted by beenthere (Post 516520)
You have a water boiler. Make sure your circulator is working. And that the valve above the circ is open.

When I turned on the thermostat and the electricty switch, I can see the circulator is rotating. I did a test. When the burner is running and I drain water from the valve above the circulator(upper one), the pipe next to radiator is warm. And ocassionly, I heard the cirulator making big noise, like a metal spring or some part came off inside and hitting the outer part circulator cover while rotating. But, when I switch off, and switch it on, the noise is gone. Does that mean the circulator is bad? I guess I need to call in a professional person......

beenthere 10-14-2010 05:17 AM

The coupling is probably broke. And needs replaced. Along with the circulator motor mounts.

fabrk8r 10-14-2010 07:54 AM

I think beenthere is correct with his diagnosis. In fact I had the exact same hot water boiler in my own house until I updated my system. The coupling broke on my circulator pump and made a nasty noise early one morning when it was really cold. The replacement part was under $20 and an easy repair. Fortunately my motor mounts were still okay.

tomhere 10-14-2010 09:28 AM

Thanks very much! fabrk8r mentioned that it's an easy fix, do you know where I can get the instruction? If I call in a pro. How much would be reasonable? I am in the east coast. I also want to fix the auto burning problem when the thermostat calls for heat.

fabrk8r 10-14-2010 09:45 AM

tomhere, have you taken a close look at your circulator pump coupler? If it's just the coupler that needs replacing it's a DIY job.

Is this what your coupler looks like? http://i89.photobucket.com/albums/k2...8r/coupler.jpg This example is cast-iron. Some like this are stamped steel. You may also have a type of rubber coupling that is sandwiched between to steel sleeves.

Most HVAC companies that work with hydronic systems will have one on the shelf and charge you anywhere from $15.00 - $30.00 for the part.

If you hire it out expect to pay about $150.00 (One hundred for the service call and 50 for the part).

tomhere 10-14-2010 10:07 AM

1 Attachment(s)
Quote:

Originally Posted by fabrk8r (Post 516695)
tomhere, have you taken a close look at your circulator pump coupler? If it's just the coupler that needs replacing it's a DIY job.

Is this what your coupler looks like? http://i89.photobucket.com/albums/k2...8r/coupler.jpg This example is cast-iron. Some like this are stamped steel. You may also have a type of rubber coupling that is sandwiched between to steel sleeves.

I believe it looks like this, it's in the area circled in the pic.

I will give it a try. Thanks again!

beenthere 10-14-2010 02:55 PM

Replace the motor mounts.

Its generally the motor mounts going bad. that cause that coupling to break.

Look at the bad motor mount. If it shows any sign of sagging on the bottom. Its bad. It should be the same height on the bottom as the top.

The coupling is easy to replace. The motor mounts are a bit harder, but not anything that is terrible to do.

AllanJ 10-14-2010 06:27 PM

If the spring assembly pictured above is broken, it is possible that the pump portion of the circulator unit is sluggish or stuck which will give you the no-heat situation you describe.

beenthere 10-14-2010 06:37 PM

Generally. The motor doesn't have enough power to break the spring in the bearing assemble is stuck, or even just tight enough that it only turns at half speed. They are only 1/12 HP motors. on the small 100 series low head units. 1/6 HP on the high head units.


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