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mike1007 12-19-2007 10:57 AM

Boiler Low Water Cut-off
I have Smith GB200 Gas fired Steam boiler with a CycleGard CG 400P low water cut-off controler. The CG400 shuts the boiler off to check the water level for about 90 seconds, the green LED light comes on indicating it is checking. After the green LED light goes off, after the 90 seconds, it takes the boiler a good 2 minutes to come back on, shouldn't it come on almost immediately after the green LED light comes off.

MgMopar 12-19-2007 12:47 PM

This may or may not be a normal condition. Are you having any other problems did it run differently before or are you noticing something for the first time? It appears most of there models have a 15 second delay for probe proving. Also avail is a probe +30 second delay to help a self filling system achieve its leaval. You boiler itself very likely has a delay and proving system. two minutes seems like a reasonable time for a cycle of proving. Mach damage and wear and tear can happen to a unit the is short cycled. I am not a expert in this area maybe some one else can give more in site on it but it doesn't necessarily seem broken.

mike1007 12-19-2007 01:13 PM

This does not have a self filling system. I'm didn't really pay attention to this before until recently when I replaced my thermostat. I have a similar Smith boiler but Oil fired with turns the boiler right after.

imported_harryo 01-14-2008 02:11 PM

set the amp setting on the new therostat.take the cover off and you'll see a little dial with different settings check the amp of the gas valve.I think i'm right because if the amp isn't set right it will cause the heater to short cycle.

mike1007 01-14-2008 03:21 PM

I figured it out. I happens the thermostat was being powered by the boiler's 24VAC and the battery was backup. Anytime the LWCO shuts the boiler off it also cuts the power to the thermostat. The termostat then switches to battery backup but it takes a couple of minutes to do this. I just disconnected the 24VAC supply to have the thermostat only operate on batter power.

imported_harryo 01-14-2008 04:57 PM

the purpose of the 24v is so the battery recharges,but what ever works for you.thanks for letting me know how you made out.

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