John Wood 4040SN-PDV - User Manual

Questions and Answers

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jennifer51Aug 18, 2025
Why John Wood 4040SN-PDV blower will not start?
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  diazkimAug 18, 2025
  The blower might not start due to several reasons. First, ensure the unit is receiving power by checking the power cord, fuses, and supply voltage. Then, make sure the thermostat setting isn't too low; increase the temperature setting if needed. A defective air pressure switch (it must be open at start-up) could also be the cause, in which case you should replace it. Other potential issues include a defective blower (replace the blower), disconnected or loose wiring (repair or reconnect the wires), or a control lockout (reset the control and determine the cause of the lockout).
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melissa91Aug 25, 2025
What to do if hot surface igniter is not glowing on John Wood 4040SN-PDV Water Heater?
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  Darlene NelsonAug 25, 2025
  If the hot surface igniter isn't glowing after the warm-up, the 120VAC polarity might be reversed at the outlet. Reverse the polarity at the 120VAC outlet receptacle. Also, the hot surface igniter could be defective, so replace it and check for 120VAC across I1 & I2 (Robertshaw only). Finally, the control itself might be defective, requiring replacement.
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Taylor StanleySep 3, 2025
How to fix a John Wood Water Heater blower that will not start?
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  jvaughnSep 4, 2025
  If the blower on your John Wood Water Heater isn't starting, here are a few things to check: First, make sure the power cord is plugged in and check the fuses and supply voltage. You might also want to increase the thermostat temperature setting. If those aren't the problem, consider replacing the air pressure switch or the blower itself. Also, check for any damaged or disconnected wires and repair or reconnect them. Finally, try resetting the system, but be sure to determine the cause of the lockout first.
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davissarahSep 7, 2025
What to do if the hot surface igniter is not glowing on my John Wood 4040SN-PDV Water Heater?
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  Christian DuncanSep 7, 2025
  If the hot surface igniter on your John Wood Water Heater isn't glowing after the warm-up period, the 120VAC polarity might be reversed at the outlet. Try reversing the polarity at the 120VAC outlet receptacle. If that doesn't work, consider replacing the igniter, ensuring you check for 120VAC across I1 & I2 (Robertshaw models only). As a last resort, you may need to replace the control.
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Leslie PerezSep 12, 2025
Why is the control locked-out with a solid green LED on my John Wood 4040SN-PDV Water Heater?
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  wadamsSep 12, 2025
  If the control on your John Wood Water Heater is locked out and shows a solid green LED, the suggested solution is to replace the control. This could also be due to ECO failure from excessive water temperature, in which case you should replace the control. Another possibility is excessive humidity or a damp environment; in this case, allow the control to dry.
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williamskimNov 14, 2025
What to do if John Wood Water Heater control locked-out?
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  Evan GreenNov 14, 2025
  If the control is locked out, there could be several reasons. First, check and turn on the gas supply. If the control switch is in the “OFF” position, turn it to “ON”. Ensure the gas supply is sufficient and at the correct pressure for your gas type (Nat Gas 7.0 in. w.c. (1.74 kPa), Propane 11.0 in. w.c. (2.74 kPa)). Verify and adjust for the correct manifold gas pressure (NG 3.5 in. w.c.(0.87 kPa), Propane 10.0 in. w.c. (2.49 kPa)). Make sure you are using the correct gas type for your water heater model. Other potential causes include a defective igniter or loose wiring (replace the igniter or reconnect the wiring), an improperly positioned, dirty, or defective flame rod (reposition, clean, or replace the flame rod and reconnect any loose wires), a clogged burner orifice (remove the obst...
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Mark Solomon MDNov 20, 2025
How to stop John Wood Water Heater blower running continuously?
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  Kimberly DunnNov 20, 2025
  If the blower runs continuously, it might be due to several reasons. The air pressure switch may not be closing due to insufficient draft. Check for a blocked vent piping, excessive piping length, a frozen vent termination or a clogged/dirty blower. Determine the cause of the insufficient draft and check the draft with a manometer at the pressure switch. Remove any blockage, reduce the vent length or increase the vent size, clear the termination of snow or ice, and clean the blower wheel. Also, inspect the pressure sensing tubing from the air pressure switch to the blower housing for disconnections, tears, or blockages; reconnect or replace the tubing as necessary. A defective air pressure switch may also cause this problem, so replace it if needed. Finally, check the high limit switch for...
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Shannon HowardNov 26, 2025
What to do if the control is locked-out on my John Wood 4040SN-PDV Water Heater?
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  Tiffany AguilarNov 27, 2025
  If the control on your John Wood Water Heater is locked-out, you can try the following: First, check and turn on the gas supply. Then, if it's a Robertshaw model, turn the control switch to the “ON” position. Ensure the supply pressure is correct for your gas type (Natural Gas should be at 7.0 in. w.c. (1.74 kPa), and Propane at 11.0 in. w.c. (2.74 kPa)). Also, check and adjust the manifold gas pressure (NG 3.5 in. w.c.(0.87 kPa), Propane 10.0 in. w.c. (2.49 kPa)). Make sure you're using the correct gas type for your water heater model. Other solutions include replacing a defective igniter or reconnecting its wiring, repositioning, cleaning, or replacing a defective flame rod and reconnecting its wiring, removing any obstruction, removing blockage or cleaning the flue, or replacing the con...
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Benjamin SmithDec 1, 2025
Why does the blower run continuously on my John Wood 4040SN-PDV?
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  Jonathan EnglishDec 1, 2025
  The blower in your John Wood Water Heater might run continuously due to several reasons. One cause could be an air pressure switch not closing because of insufficient draft. To solve this, determine the cause of the insufficient draft and check it with a manometer at the pressure switch. You may need to remove blockages, reduce the vent length or increase its size, clear the termination of snow or ice, or clean the blower wheel. Other potential solutions include reconnecting or replacing the pressure sensing tubing, replacing a defective pressure switch, or addressing a high limit switch that's open due to excessive vent temperature or a defective switch. If overheating is the cause, check for overfiring, insufficient air supply, or high ambient air temperature. Note that once activated, t...