Boiler not kicking on - did bleeding the rads cause it?

**trickycain** · 11-05-2011, 09:59 PM

So, I bled my radiators yesterday to try and resolve loud, clanking pipes when the heat was actually working. Air came out of the radiators on the 2nd floor, and little to no air came out of rads on 1st floor.

Ever since bleeding the rads, the boiler has not kicked-on, and I have a pressure reading of zero at gauge on the boiler.

It's a hydronic system by Weil-McLain (CG fired with natural gas). I don't think there's any kind of external way to add water to increase the pressure (there's not a fresh water line leading into the system that I can detect), rather I think everything is closed off (closed loop?). So, I am hoping everything is resolved by fixing the pressure issue - if this is the case, can I fix this issue at the expansion tank (I have the kind with the bike valve stem at the bottom) Or is there some other kind of trickery that I do not know about? I really don't want to get into adding fresh water, for obvious reasons, and I feel like there's a simple solution here that I just don't know about.

Thank you very much in advance

**Tom Sawyer** · 11-06-2011, 04:47 AM

If the boiler pressure is zero you need to add water and if there is no auto-fill or cold water make up pipe to the system you will need to pump it in.

**trickycain** · 11-06-2011, 06:05 AM

OK, I was able to add water after finally locating the feeder valve. The pressure is looking good on the gauge, but still the boiler refuses to kick-on.

Is this a pilot issue now?

**trickycain** · 11-06-2011, 06:57 AM

Strike that, I have an intermittent pilot, so I guess it's can't really "go out." Right?

**Tom Sawyer** · 11-06-2011, 07:19 AM

Kill the power to it, wait about 30 seconds and turn it back on

**trickycain** · 11-06-2011, 09:28 AM

still no dice. not sure what's going on here.

**Tom Sawyer** · 11-06-2011, 10:29 AM

Could be a bunch of things. Probably time to call a service tech.

**jadnashua** · 11-06-2011, 01:06 PM

There are numerous safety interlocks on a boiler. One of the interlocks could be stuck, broken, or you could have a real problem. Does the burner try to turn on then stop, or does it never turn on? Your low-pressure cutout switch could be stuck. All of this is fairly easy to test, if you can find it and have a clue what you are doing. The control circuit is mostly low-voltage (typically 24vac), and straightforward.

The manual will have a troubleshooting chart and theory of operation discussion along with a wiring diagram.

**trickycain** · 11-06-2011, 06:19 PM

Boiler just doesn't turn on at all. Think you're right about the low pressure cut out, but I can't find it and I can't locate it in the manual.

I don't see any kind of reset button or switch. How in the world do I get this thing kicked on?

**jadnashua** · 11-06-2011, 08:35 PM

Post a link to the manual, and maybe someone can help point it out. Essentially, when the thermostat calls for heat, typically, 24vac winds its way through the safety interlocks to the ignitor...if it's stopped anywhere along the way with an open switch, nothing happens. It's a matter of tracing that 24vac from the input to the ignition circuit. The wiring diagram generally shows this, but it isn't always the easiest thing to follow if you've not played with it before. They use some weird symbols that are different from those used on more complex electronic ones, but there's usually a key somewhere on the diagram.