Burner Not turning On

STvex

Good Morning,

I have a weil McClain hot water boiler cg 15.  Today my burners won't turn on.  The thermostats are calling for heat, I hear the damper opening, the circulator is on but the burners don't turn on. I unplugged the red switch by the damper coller and it closes the damper. Any other place I can check for?  I attached two pics.  Boiler was working fine yesterday.  

Thanks in advance.

Ironman

LP or Natural gas? Is there fuel to the appliance?

Any open safeties?

Beyond that, there’s not enough info to suggest anything else and a meter and the skill to use it are gonna be needed.

gyrfalcon

Do you have a pilot light? Is it lit?

Steamhead

No pilot light- I see a Honeywell spark module on the side. It may have been upgraded with a spark-ignition kit.

Next thing I'd check is the roll-out safety.

pedmec

Check the spill switch on the draft hood. Its in series with the gas valve. The draft damper was opened so there was a call for heat. Press the red button in the middle to reset

STvex

Thanks.  I have gas with electronic ignition.  I tried to press the red button on the hood collar but it doesn't go anywhere.  What is the piece called and what is its purpose?

pedmec

Its called a spill switch and prevents the boiler from coming on if there is an issue venting the products of combustion. You don't want the products of combustion spilling out of the draft hood.

JUGHNE

Then there is the roll out switch as Steamhead pointed out.

Usually a one time fuse link down at the burners.

If you have 24 volts across the connections to that, when there is a call for heat, then it is open and needs replaced after you find the cause for failure.

STvex

Thank you all.  I will replace both switches, seems easy to do.  Besides these two, any other part I can replace?  

EdTheHeaterMan

STvex said:

Thank you all.  I will replace both switches, seems easy to do.  Besides these two, any other part I can replace?  

Before you do that you want to check this

JUGHNE said:

Then there is the roll out switch as Steamhead pointed out.

Usually a one time fuse link down at the burners.

If you have 24 volts across the connections to that, when there is a call for heat, then it is open and needs replaced after you find the cause for failure.

So the simple test is to find the ceramic limit switch that looks like this:It is located down near the burner access door. If you connect the 2 wires together with a paperclip or some other TEMPORARY jumper, then the burner starts. you have found the defective part. If you don't get the burner to start with this test, then replacing non defective parts with "new" non defective parts will only cost you money without the desired result.

Only replacing defective parts with good parts will fix the problem.

If you get the heater to operate with the jumper, you must first remove the jumper. DO NOT OPERATE with a safety limit disconnected or with a jumper in place.
Next thing is to find out why the safety limit device did what it did.
Then finally after finding the cause of the failure, you can put the replacement part on and operate the system

EdTheHeaterMan

DO NOT OPERATE with a safety limit disconnected or with a jumper in place.

the reason this is so important is
1. The roll out switch is to protect you from operating the burner if the heat exchanger is clogged or blocked
2. A blocked heat exchanger will not allow the dangerous byproducts of combustion to vent properly up the chimney
3. Byproducts of combustion will melt the other components inside the front door of the heater and may cause the gas valve to get stuck open.
4. Byproducts of combustion contain carbon monoxide that can make you sick while you sleep if not vented out the chimney properly.
Skip to the last of many reasons
168. You could die.

STvex

Thank you for the comments.  I replaced both the spill switch and flame roll out which didn't cost that much but still the burner won't turn on.. at this point multi meter to check each part?

WMno57

Yes. Get the multi meter.

HVACNUT

Should there be a Green light lit on the low water cut off?