weil mclain Gold CGa boiler wont run after temperature reaches 180 degree

Bosco

HELP.
I have this weil mclain Gold CGa boiler wont run after temperatures reaches 180 degree. It stop but never fire anymore. Once turn power off and on, it will also run away for one time, then stops again when water reaches 180 degree. When it stopped, the control board will have power light on, TSTAT/CIRC light on, and LIMIT light on. see pic. please help how to fix it

HVACNUT

The boiler reaches 180° with the temperature and economy settings as shown in the pic?
Try raising the boiler temperature and lower the economy to minimum. 

fentonc

I have that same boiler - Assuming 'boiler temp' is set to 180.0, the boiler fires until the water reaches that temperature (the 'high limit' of the aquastat), then it stops firing and continues circulating until the water temp falls to 160, at which point, if the call for heat is still present, it fires up again until the water temp is back to 180.0, repeating that cycle until no thermostats are calling. Is this not the behavior you're seeing?

kcopp

Looks like there may be water on that control board...or is that an optical illusion?

Bosco

@fentonc, that what would normally happens, it shall re-fire once temp. dropped around 160degree, but it didnt anymore.

@kcopp, I did try to install remove the LWCO to clean it and install back in. Water may have dripped a bit to the control board. I wasnt sure or paying attention. Does it make the board malfunction? Can I use alcohol to clean it?

Bosco

fentonc said:

I have that same boiler - Assuming 'boiler temp' is set to 180.0, the boiler fires until the water reaches that temperature (the 'high limit' of the aquastat), then it stops firing and continues circulating until the water temp falls to 160, at which point, if the call for heat is still present, it fires up again until the water temp is back to 180.0, repeating that cycle until no thermostats are calling. Is this not the behavior you're seeing?

@fentonc, that what would normally happens, it shall re-fire once temp. dropped around 160degree, but it didnt anymore.

kcopp said:

Looks like there may be water on that control board...or is that an optical illusion?

@kcopp, I did try to install remove the LWCO to clean it and install back in. Water may have dripped a bit to the control board. I wasnt sure or paying attention. Does it make the board malfunction? Can I use alcohol to clean it?

EBEBRATT-Ed

Are your circulators running?

HVACNUT

Check the vent damper. Is it open? The flat arm out of the motor to the damper should be parallel with the flue.
If it's open, turn off the power and find the auto/manual switch on the damper motor housing. Switch it to manual. Turn the power back on and see what happens.
If it works, it's a bad end switch in the damper. You could leave it like that. It'll just cost a little in efficiency. 
I'm surprised the boiler reaches 180° considering where the settings are. 

Bosco

EBEBRATT-Ed said:

Are your circulators runninng?
yes, circulators are still running. 

@HVACNUT I will check the damper.