Department Of Energy Compliance; Operation- Spark-Ignited Pilot Boilers - Weil-McLain CGA 2 Series Installation And Maintenance Manual

COa Series 2 Gas-Fired Water Boiler - Boiler Manual
8
Department of Energy - Compliance
This boiler is equipped with a control system that automatically adjusts a time delay period to turn on the boiler
during a call for heat. This is accomplished by circulating available hot water in the system while measuring
water boiler water temperature changes. The control calculates a suitable delay based on temperature measure-
ments and turns the boiler on only after it determines that the demand for heat cannot be satisfied with the
available hot water,
Due to the wide variety of controls used in boiler installations, this control is also equipped with an adjustment
for the calculated time delay period (ECONOMY ADJUST). In the MIN position, the time delay is zero and the
IMPORTANT notice below must be observed:
IMPORTANT
In
accordance with
Section 325 (f)
(3) of the Energy Policy and Conservation Act, this boiler is equipped with
a feature that saves energy by reducing the boiler water temperature as the heating load decreases. This feature
is equipped with an override which is provided primarily to permit the use of an e:cternal energy management
system that serves the same function.
THIS OVERRIDE MUST NOT BE USED UNLESS
iiT LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE:
An external energy management system is installed that reduces the boiler water temperature as the heating load
decreases.
This boiler is part of a modular or multiple boiler system having a total input of 300,000 BTU/hr or greater.
This boiler is equipped with
a
tanlde<..s coil.
9 a
Operation - spark-ignited pilot boilers
NOTICE
Follow all procedures given in this manual
and operating instructions when operating the
boiler. Failure to do so could result in severe
personal injury, death or substantial property
damage.
I. Standby: With no call for heat, the vent damper and circulator
are de-energized. No gas flows to pilot or main gas valve.
2. Call for heat (thermostat circuit closes):
34
a. While attempting to satisfy the heat demand, the control
module monitors the boiler temperature changes via the
temperature sensor and determines whether or not the
available hot water will satisfy the demand, only running
the circulator. If additional heat is needed, the sequence
continues. When DHW
(if used) calls for heat, sequence
above is bypassed.
b. Vent damper and circulator energized if pilot status ac-
ceptable. Vent damper drives open. When vent damper end
switch makes circuit, ignition control begins pilot ignition
attempt.
c.
Ignition control checks for false flame signal: If ignition
control senses pilot signal when no pilot gas should be
present, control will lockout, requiring reset procedure as
given in Figure
24.
3. Pilot ignition: Control module sparks the pilot and opens pilot
valve in main gas valve.
a. If pilot does light and control module senses flame
current, spark generator is turned off and main valve
opens.
b. Natural
Gas -
If pilot does not light within IS seconds,
pilot valve
is
closed and spark generator is turned off. Control
module waits
5
minutes, then attempts to ignite pilot again.
This cycle will continue indefinitely if pilot ignition control
does not sense pilot flame.
Part Number 550-142-779/0712