LAARS 9600 CB - Installation, Operation and Maintenance Instructions - Manual (Page 20)

13-427D
Quick Reference Trouble Shooter
A. SHORT CYCLING:
1. CB - Boiler oversized for total load or small zone
2. CB - Units shuts down before reaching limit. Continuously restarts without resetting
a. Limit out of calibration
b. Wrong air/gas orifices for input or fuel (refer to 9600 gas orifice chart ONLY)
c. Thermostat heat anticipator set below 0.9 amps.
B. OVERHEATS QUICKLY OR KNOCKS DURING OPERATION:
Boiler noise in combustion chamber.
1. Air in combustion coil or in pump: Purge system
2. Pump failure or control failure.
3. Restriction in supply/return piping.
4. Defective mixing valve element.
C. DELAYED IGNITION:
Unit starts or stops with a “pop”.
1. Wrong gas orifice for fuel or air orifice size.
2. LP - Gas regulator lock up 3" or greater above run pressure: correct regulator and check gas pipe sizing against
piping chart in installation manual. Set regulator for maximum run pressure of 9".
3. Remove blower and inspect flame holder (burner) for hole.
4. Check that the blower flanges and gas piping are sealed.
D. OCCASIONAL LOCKOUTS:
Requires interruption of power to re-start or reset of safety limit.
1. Air in system causes safety limit to open. Vent air from system and find and eliminate source.
2. Condensing in primary heat exchanger or moisture in combustion chamber
a. defective element in diverting valve
b. improper installation of intake terminal
c. blocked condensate and condensate overflow system
3. Poor Combustion - check CO2 or 02.
4. Intermittent igniter failure: defective igniter gasket allows igniter base to overheat.
5. Occasional failure of blower: red “PURGE” light will be flashing.
6. Zone control short cycling or voltage problem: Operate thermostats in various sequences to create suspect
problem: Note: Three wire zone valve such as Taco or Watts must have isolating relay between end switch and
CB boiler.
800.900.9276 • Fax 800.559.1583 (Customer Service, Service Advisors)
20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax 905.366.0130
www.Laars.com Litho in U.S.A. © Laars Heating Systems 0805 Document 1101D