Install Instructions

1.1. 1.1.
1. Modulating valve improperly installed.
2.2. 2.2.
2. See symptom "K."
1.1. 1.1.
1. Arrow on side of valve point in direction of gas flow.
1.1. 1.1.
1. Install properly.
3.3. 3.3.
3. Check for 24V AC at terminals (amplifier - 1 and 2, amplifier/selector - 7 and 8).
4.4. 4.4.
4. Perform temperature sensing function test outlined in "Preliminary Circuit Analysis."
5.5. 5.5.
5. Measure resistance across modulator terminals with lead wires disconnected.
6.6. 6.6.
6. Perform modulating function test as outlined in "Preliminary Circuit Analysis."
7.7. 7.7.
7. Perform temperature sensor function as outlined in "Preliminary Circuit Analysis."
3.3. 3.3.
3. Prove the source.
4.4. 4.4.
4. If modulating voltages are obtained, check sensor for open circuit. Correct
wiring.
5.5. 5.5.
5. Replace modulator head (if available) or modulator if resistance is not
approximately 45-55 ohms for M611, M620, and M651; 50-65 ohms for M511, M520, and M551; and 60-80 ohms for M411, M420, M451, and MR212.
6.6. 6.6.
6 . Prove the power source, and if it checks out, and modulating function test
determines no modulating voltages, controller or amplifier with remote temperature selector may be at fault. Replace.
7.7. 7.7.
7. If modulating voltages are obtained, check sensor wiring and sensor for short
circuit. Correct wiring.
8.8. 8.8.
8. If heater goes to high fire, system is working correctly.
9.9. 9.9.
9. Increase inlet pressure if possible.
10.10. 10.10.
10. Clean or replace plunger if necessary. Installed as illustrated.
SYMPTOMSYMPTOM SYMPTOMSYMPTOM
SYMPTOM
POSSIBLE CAUSEPOSSIBLE CAUSE POSSIBLE CAUSEPOSSIBLE CAUSE
POSSIBLE CAUSE
FIELD TESTFIELD TEST FIELD TESTFIELD TEST
FIELD TEST
REMEDYREMEDY REMEDYREMEDY
REMEDY
Field Service ChecklistField Service Checklist Field Service ChecklistField Service Checklist
Field Service Checklist
3.3. 3.3.
3. No voltage to the controller/amplifier.
4.4. 4.4.
4. Open circuit in temperature sensor wiring.
5.5. 5.5.
5. Open circuit in modulator coil.
6.6. 6.6.
6. No voltage to the modulator.
7.7. 7.7.
7. Short circuit in temperature sensor wiring.
8.8. 8.8.
8. Heat load requires low fire only.
9.9. 9.9.
9. Inadequate supply pressure.
10.10. 10.10.
10. Plunger missing, jammed, misinstalled.
8.8. 8.8.
8. Increase temperature setting 10 degrees.
9.9. 9.9.
9. Read pressure at inlet to modulating valve using a manometer with unit operating
at full fire. Pressure should be greater or equal to the sum of outlet pressure setting plus pressure drop of the valve (See Maxitrol capacity chart - bulletin MT2035).
10.10. 10.10.
10. Inspect. Plunger should be installed as illustrated and operate freely in solenoid sleeve.
11.11. 11.11.
11. Incorrect by-pass metering valve
adjustment.
12.12. 12.12.
12. Excessive negative burner pressure
(direct-fired only).
11.11. 11.11.
11. See valve adjustments on page 8.
12.12. 12.12.
12. Close main gas supply and measure manifold pressure with blower operating.
Reading should be less negative than 1.5 inches w.c. (3.7 mbar) negative pressure. (MR212D, E, G, J, M411, 511, M611)
11.11. 11.11.
11. Adjust to proper minimum fire.
12.12. 12.12.
12. If reading is more negative than 1.5 inches negative pressure, check for
clogged filters or other inlet air restrictions. (MR212D, E, G, J - are field adjustable to 3.5 inches w.c. [9 mbar] negative pressure. Check manufacturer's design requirements to ensure proper setting.) Consult factory for other solutions.
No gas flow.No gas flow. No gas flow.No gas flow.
No gas flow.
Continuous Low FireContinuous Low Fire Continuous Low FireContinuous Low Fire
Continuous Low Fire
(Electronics OK).(Electronics OK). (Electronics OK).(Electronics OK).
(Electronics OK).
Incorrect Low Fire.Incorrect Low Fire. Incorrect Low Fire.Incorrect Low Fire.
Incorrect Low Fire.
Continuous Low FireContinuous Low Fire Continuous Low FireContinuous Low Fire
Continuous Low Fire
(Electronic Problem).(Electronic Problem). (Electronic Problem).(Electronic Problem).
(Electronic Problem).
13.13. 13.13.
13. Remove bottom plate and inspect valve and seat.
14.14. 14.14.
14. If main diaphragm gasket & diaphragm replaced, check for proper installation/alignment.
15.15. 15.15.
15. Inspect. Plunger should be smooth and clean, and operate freely in solenoid sleeve.
13.13. 13.13.
13. Foreign object holding valve open.
14.14. 14.14.
14. Improper diaphragm installation.
15.15. 15.15.
15. Plunger jammed.
13. If necessary, clean seat and valve, or replace if applicable. 14. Install and align properly. 15. Clean, or if necessary, replace plunger.
16.16. 16.16.
16. Read pressure at inlet to modulating valve using a manometer with unit operating
at full fire. Pressure should be equal to the sum of outlet pressure plus pressure drop of the valve (see Maxitrol capacity chart - bulletin MT2035).
17.17. 17.17.
17. Read manifold pressure using manometer and compare with recommendation
of heater manufacturer.
16.16. 16.16.
16. Inadequate supply pressure.
17.17. 17.17.
17. Incorrect outlet pressure adjustment
of pressure regulator.
16. Increase inlet pressure if possible. 17. See valve adjustments on page 8.
18.18. 18.18.
18. Hunting.
19.19. 19.19.
19. Erratic air patterns or improper temperature
sensor location.
20.20. 20.20.
20. Controller/amplifier wiring is run next
to high voltage switching circuits causing induced voltages.
21.21. 21.21.
21. Erratic voltage supply.
22.22. 22.22.
22. Erratic inlet pressure.
18.18. 18.18.
18. Controller/amplifier may require "sensitivity" adjustment.
19.19. 19.19.
19. Perform temperature sensor function test as outlined in "Preliminary Circuit Analysis."
20.20. 20.20.
20. Connect with temporary wiring clear of induction source, or when possible turn "off"
source of induced voltage.
21.21. 21.21.
21. Connect AC voltmeter across terminals (amplifier -1 & 2, amplifier/selector -7 & 8).
22.22. 22.22.
22. Measure inlet during operation.
18. Contact Maxitrol Service Manager. 19. If the flame is steady throughout the entire modulating range, the sensor
must be moved.
20. If smooth operation results, isolate wiring from source of induced
voltage.
21. If erratic operation is noted only over a small range of 2 or 3 volts, the
voltage source may contain surges. Consult Maxitrol.
22. Investigate regulator upstream of modulator.
23. Move sensor to location where desired temperature can be sensed.
23.23. 23.23.
23. Improper temperature sensor location.
23.23. 23.23.
23. Sensed temperature (thermometer next to sensor) does not represent average air temperature.
24.24. 24.24.
24. Short circuit in modulator coil.
25.25. 25.25.
25. Coil shorted to ground.
26.26. 26.26.
26. Short circuit - controlled/amplifier
and modulator.
24. Replace modulator head (if available) or modulator if resistance is not
approximately 45-55 ohms for M611, M620, and M651; 50-65 ohms for M511, M520, and M551; and 60-80 ohms for M411, M420, M451, and MR212.
25. Replace modulator head (if available) or modulator. 26. Correct wiring if short is found (shorted modulator/modulator-regulator valve
will damage amplifier).
24.24. 24.24.
24. Measure resistance across modulator terminals with lead wires disconnected.
25.25. 25.25.
25. Measure resistance from each terminal to ground.
26.26. 26.26.
26. Inspect wiring.
Continuous High FireContinuous High Fire Continuous High FireContinuous High Fire
Continuous High Fire
(Electronics OK).(Electronics OK). (Electronics OK).(Electronics OK).
(Electronics OK).
Incorrect High Fire.Incorrect High Fire. Incorrect High Fire.Incorrect High Fire.
Incorrect High Fire.
Erratic or Pulsating Flame.Erratic or Pulsating Flame. Erratic or Pulsating Flame.Erratic or Pulsating Flame.
Erratic or Pulsating Flame.
Incorrect Air Temperature.Incorrect Air Temperature. Incorrect Air Temperature.Incorrect Air Temperature.
Incorrect Air Temperature.
Burned -out Transformer.Burned -out Transformer. Burned -out Transformer.Burned -out Transformer.
Burned -out Transformer.
The following items do not apply to remote system amplifier model A1494.The following items do not apply to remote system amplifier model A1494. The following items do not apply to remote system amplifier model A1494.The following items do not apply to remote system amplifier model A1494.
The following items do not apply to remote system amplifier model A1494.
27.27. 27.27.
27. Faulty automatic control valve.
28.28. 28.28.
28. Installation wiring error.
29.29. 29.29.
29. Controller/amplifier wiring is faultly.
27. Replace automatic control valve. 28. Correct wiring. 29. Replace controller/amplifier.
27.27. 27.27.
27. Remove wire from valve. If valve doesn't close, valve is faulty.
28.28. 28.28.
28. Remove wire from terminal (amplifier -5 [or 1- commonpower supply], amplifier/
selector -5 [or 8 -common power supply]). If valve remains open, check for mis-wiring.
29.29. 29.29.
29. Perform auto valve function test as outlined in "PreliminalryCircuit Analysis."
Automatic Cotrol ValveAutomatic Cotrol Valve Automatic Cotrol ValveAutomatic Cotrol Valve
Automatic Cotrol Valve
will not close despite fullwill not close despite full will not close despite fullwill not close despite full
will not close despite full
range of modulatingrange of modulating range of modulatingrange of modulating
range of modulating
voltage at terminals 3 & 4.voltage at terminals 3 & 4. voltage at terminals 3 & 4.voltage at terminals 3 & 4.
voltage at terminals 3 & 4.
30.30. 30.30.
30. Faulty automatic control valve.
31.31. 31.31.
31. Open wire to automatic valve.
32.32. 32.32.
32. Controller/amplifier relay is faulty.
30. Replace automatic control valve. 31. Correct wiring. 32. Replace controller/amplifier.
30.30. 30.30.
30. Read voltage across auto valve terminals. If 24 AC, valve is faulty.
31.31. 31.31.
31. Read voltage across terminals 5 and 6. If 24V AC, check for open circuit
to automatic valve.
32.32. 32.32.
32. Perform auto valve function test as outlined in "Preliminary Circuit Analysis."
Automatic Control ValveAutomatic Control Valve Automatic Control ValveAutomatic Control Valve
Automatic Control Valve
will not open despite fullwill not open despite full will not open despite fullwill not open despite full
will not open despite full
range of modulatingrange of modulating range of modulatingrange of modulating
range of modulating
voltage at terminals 3 & 4.voltage at terminals 3 & 4. voltage at terminals 3 & 4.voltage at terminals 3 & 4.
voltage at terminals 3 & 4.
A.A. A.A.
A.
B.B. B.B.
B.
C.C. C.C.
C.
D.D. D.D.
D.
E.E. E.E.
E.
F.F. F.F.
F.
G.G. G.G.
G.
H.H. H.H.
H.
I.I. I.I.
I.
J.J. J.J.
J.
KK KK
K
4