FloAire FAV-M - Manual (Page 35)

35
Maxitrol Series 14 Troubleshooting
Symptom Possible Cause Field Test Remedy
No Gas Flow Modulating valve improperly
installed Arrow on side of valve should
point in direction of gas flow Install properly
Continuous low fire
(electronics problem) Short circuit or no voltage to
the amplifier
Open circuit in TD114 remote
temperature selector or wiring
Short circuit in TS114 remote
temperature circuit or wiring Check for 24-V at amplifier
terminals 7 & 8
Check wire connections
between amplifier terminals 1
and 2 and remote
temperature selector terminals
1 and 3
Follow test procedures as
outlined in the preliminary
testing section of this manual Prove power source
Tighten connections or
replace wiring
If modulating voltages
are obtained, check
TS114 if necessary. If
these items check out
and modulating voltages
are still not obtained,
amplifier may be
assumed defective.
Install replacement.
Continuous low fire
(electronics OK) Faulty amplifier
Open circuit in modulator coil
Plunger missing, jammed, or
improperly installed Check Td114 for internal open
circuits. Maximum 11,500
ohms across terminals 1 and 3
with external wiring
disconnected. Measure
resistance across modulator
terminals with interconnecting
wires disconnected.
Inspect: Plunger should
operate freely in solenoid
sleeve. Replace modulator head
if not approximately 45
to 55 ohms for the M611
and M511 and 60 to 80
ohms for the MR212.
Clean or replace plunger
if necessary.
Incorrect minimum fire Incorrect by-pass metering
valve adjustment
Excessive negative burner
pressure Re-set low fire (see start-up
instructions)
Close main-gas supply and
measure manifold pressure
with blower opening. Reading
should be less than 1.5-in wc
negative pressure. Adjust to proper low fire
If reading is greater than
1.5-in wc negative
pressure, check for
clogged filters or other
inlet air restrictions.
Continuous high fire
(electronics problem) Short circuit in remote
temperature selector circuit
Open Circuit in the TS114
discharge air sensor circuit
Jumper not connected across
amplifier terminals 2 and 3 Inspect for shorts at or
between amplifier terminals 1
and 2 and at TD114 terminals
1 and 3.
Check TS114 for terminal
shorts, minimum 8,000 ohms
across terminals 1 and 3 with
external wiring disconnected.
Connect test resistor as
described in the preliminary
circuit test. Correct wiring if a short
is present. Replace
TD114 if defective.
If modulating voltages
are obtained, check
TS114 circuit for shorts.
Replace TS114 if
necessary.
Correct if necessary.