Posted by Wes on October 25, 2001 at 22:26:17:
In Reply to: Instant Highfire! posted by Robert on October 24, 2001 at 10:06:35:
This is how our CB-350's normally operate.
When they are on manual the potentiometer controls the fire rate.
When they are on automatic the fire rate is controlled by a pressure transducer.
Normally when I test LWCO's the pressure drops enough that if it were on automatic it would go to high fire.
I am assuming that the boiler lights on low fire then goes to high fire. If it lights on high fire then your modulating motor or the wiring going to it is probably bad.
: I have a Cleaver Brooks 125 hp firetube boiler generating 100psi steam. This morning I discovered that after blowing down boiler and after prepurge boiler came on line as normal but went to 100% fire even though it was set to only go to 50%. In automatic mode it is bypassing the preset setting (ignoring it) and continuing to 100% fire. When I switch to manual mode it will stop at the preset mode of 50% fire. Where should I start looking for the problem? Modulator motor?