LAARS 9600 CB & HWG - Service Manual User Manual
Page 24
Quick Reference Trouble Shooter
A. SHORT CYCLING:
1. 9600 HWG - tank aquastat set too high
2. 9600 CB and 9600 HWG - 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 HeatMaker 9600 gas orifice chart ONLY)
c. Thermostat heat anticipator set below 0.9 amps. (9600 CB only).
3. 9600 CB - boiler oversized for total load or small zone.
B. HEATMAKER 9600 OVERHEATS QUICKLY OR KNOCKS DURING OPERATION:
Boiling noise in combustion chamber.
1. Air in combustion coil or in pump: Purge system
2. Pump failure or control failure.
3. 9600 HWG lime buildup in primary heat exchanger.
4. 9600 HWG restriction in storage tank piping.
5. Defective diverting valve element.
6. 9600 CB restriction in supply/return piping.
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 flameholder (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 form system and eliminate source of
air (9600 CB mostly).
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 O2.
4. Intermittent igniter failure: defective igniter gasket allows igniter base to overheat.
5. Occasional failure of blower: red “PURGE” light will be flashing.
6. 9600 CB zone control short cycling or voltage problem: Operate thermostats in various sequences
to create suspect problem. Note: Three wire zone valves such as Taco or Watts must have isolating
relay between end switch and HeatMaker 9600 CB.
800.900.9276 • Fax 800.559.1583
(Customer Service, Service Advisors)
20 Industrial Way, Rochester, NH 03867 • 603.335.6300 • Fax 603.335.3355
(Applications Engineering)
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 0810 Document 2109