GAS-FIRED BOILER

Boiler Manual

PART 14: TROUBLESHOOTING (CONTINUED)

Table 14-2: 925 Control Board FAULT Codes

Code

Description

 

Remedy

 

 

1.

Check circulation pump operation

 

 

2.

Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the

 

 

 

return thermister to the supply thermister.

 

 

3.

Check thermister reading on supply thermister. Replace switch if faulty.

F00

High Limit Exceeded.

4.

If this is a new installation, disconnect the two light grey wires from the zone control, and twist the wires together. Depress the S4 reset

„

 

 

button. If the fault clears, the problem is outside the boiler

 

 

5.

If this is an existing installation with glycol in it, check the condition of the water pressure switch. It may be necessary to jump out the water

 

 

 

pressure switch (temporarily only, as a trouble shooting aid) The 24 VAC signal, may have grounded through the glycol if the water pressure

 

 

 

switch is leaking.

 

 

1.

Push the red reset button on the switch.

 

 

2.

Check the flue temperature during operation using a combustion analyzer.

F01

Vent Temperature Limit Exceeded.

3.

Replace the vent limit switch if faulty.

„

 

4.

Verify the combustion drain if clear and draining properly.

 

 

5.

Visually inspect the target wall to see if it is intact. If not intact replace target wall.

 

Interrupted or Shorted

1.

Check the electrical connection to the thermister on the outlet manifold. Verify 5 VDC by checking in Molex connector. Verify thermister

F02

 

values by referencing chart in this manual.

Supply (Outlet) Thermister.

 

„

2.

Replace thermister if necessary.

 

 

 

Interrupted or Shorted

1.

Check the electrical connection to the thermister on the inlet manifold. Verify 5 VDC by checking in Molex connector. Verify thermister

F03

 

values by referencing chart in this manual.

Return (Inlet) Thermister.

 

„

2.

Replace thermister if necessary.

 

 

 

Supply (Outlet)

1.

Check circulation pump operation.

F05

2.

Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the

Temperature exceeds 230°F.

„

 

return thermister to the supply thermister.

 

 

 

F06

 

1.

Check circulation pump operation.

Return (Inlet) Temperature

2.

Assure that there is adequate flow through the boiler by accessing the status menu and assuring that there is less than a 50°F rise from the

„

Exceeded 230°F.

 

return thermister to the supply thermister.

 

 

3.

Check direction of flow on boiler circulator. (See Piping Details in this manual.)

 

 

1.

Watch the igniter through the observation window provided.

 

No flame detected – The boiler will

2.

If there is no spark, check the spark electrode for the proper ¼” gap. Use 2 quarters together as a gauge to hold ignitor against to check

 

make three attempts at ignition

 

gap distance.

F09

before the control goes into this

3.

Remove any corrosion from the spark electrode and flame rectifier probe.

„

lockout condition. *See spark

4.

If there is a spark but no flame, check the gas supply to the boiler.

 

electrode detail.

5.

If there is a flame, check the flame sensor.

 

 

6.

Check any flue blockage or condensate blocks.

 

 

1.

Monitor the gas pressure to the unit while in operation.

 

 

2.

Assure that the flame is stable when lit.

 

Loss of Flame Signal – The boiler

3.

Check to see if the green light on the display module is out while the boiler is running.

F10

will relight 4 times before the control

4.

If the green light doesn’t come on or goes off during operation check the flame signal on the status menu.

„

goes into this lockout condition.

5.

If the signal reads less than 1 microampere, clean the flame rectifier probe.

 

 

6.

If the flame rectifier probe continues to read low, replace it.

 

 

7.

Check the stability of the flame rectification signal. If the signal is unstable, you may need to replace the burner gasket.

 

 

1.

Turn the gas off to the unit at the service valve.

 

 

2.

If the flame signal is still present replace the igniter.

 

False Flame Signal – The boiler will

3.

If the flame signal is not present after turning off the gas supply, check the gas valve electrical connection.

F11

lock out if it senses a flame signal

4.

If there is no power to the gas valve, remove the valve and check for obstruction in the valve seat or replace the gas valve.

„

when there should be none present.

5.

Turn the gas on at the service valve after corrective action is taken.

 

 

6.

Check for condensate back up. Condensate back up can damage the refractory wall, and if the wall falls against the rectifier probe, it may

 

 

 

conduct the signal to ground, giving a false reading.

 

Combustion Fan Speed Low – The

1.

Check the combustion air fan wiring.

 

boiler will lock out if it senses that

1a.

Check the quality of the 24 VAC signal by measuring from any connected safety to ground. A low voltage situation may cause a “false”

F13

the fan speed is less than 70% of

 

error code

expected rate for more than 60

2.

Replace the combustion air fan.

„

 

seconds.

3.

Replace the control board.

 

Combustion Fan Speed High – The

1.

Check the combustion air fan wiring.

 

boiler will lock out if the fan speed is

F14

2.

Replace the combustion air fan.

more than 130% of expected rate for

3.

Replace the control board.

„

 

more than 60 seconds.

 

 

 

 

1.

Make sure the connector is correctly connected to the gas valve.

 

 

2.

Check the electrical wiring from the valve to the control board.

 

 

2a.

Voltage readings will be from 18-22 VDC on the outlet of the gas valve plug from any pin to ground, the connector must remain in contact

F18

Gas Valve Error

 

with the pins.

„

 

2b.

On the 399M only, check the 24 VAC relay block.

 

 

3.

Replace the low voltage wiring harness assembly.

 

 

4.

Replace control board.

„

Supply voltage frequency out of range. (92-132 VAC 60 Hz)

F19

 

 

 

„

Watchdog

Call factory for further assistance. Watchdog

F30

 

 

 

„

Parameter Memory

Call factory for further assistance. Parameter memory error, reprogramming needed

F31

 

 

 

„

Parameter Memory Write Error

Call factory for further assistance. Parameter memory write error

F32

 

 

 

„

Programming Error

Call factory for further assistance. Parameter memory error, reprogramming needed

F33

 

 

 

„

Parameters Programmed

Press S4 reset

PP

 

 

 

„

Internal processor error, due to incoming voltage problems. (92-132 VAC 60 Hz). May also occur if neutral wire has been broken or damaged.

Nc

 

 

 

„

Internal error

 

 

F

 

 

 

 

 

60

Page 61
Image 61
Munchkin Gas-Fired Hot Water Boiler manual Part 14 Troubleshooting, Control Board Fault Codes Description Remedy

Gas-Fired Hot Water Boiler specifications

The Munchkin Gas-Fired Hot Water Boiler is a highly efficient heating system that has garnered attention in residential and commercial applications for its innovative design and advanced technology. This boiler is compact yet powerful, providing exceptional heating performance while maximizing energy efficiency.

One of the standout features of the Munchkin boiler is its modulating condensing technology. This system allows the boiler to adjust its output based on demand, which optimizes energy use and reduces unnecessary fuel consumption. By modulating the flame, the Munchkin boiler can maintain a steady heating output even during variable load conditions, ensuring that users enjoy consistent hot water without waste.

The Munchkin boiler offers an impressive AFUE (Annual Fuel Utilization Efficiency) rating, typically exceeding 95%. This high efficiency translates to significant savings on energy bills and a reduced carbon footprint. By capturing and reusing flue gases that would otherwise be lost, the condensing feature enhances the overall efficiency, making it a sustainable choice for modern heating needs.

In terms of installation, the Munchkin boiler is designed for versatility. Its compact size allows for easy placement in tight spaces, whether in residential basements or utility closets. The unit is compatible with a variety of piping systems and can be integrated with multiple heating sources including radiators, baseboards, and even in-floor heating setups.

Another notable characteristic of the Munchkin boiler is its advanced control system. The boiler is equipped with a user-friendly digital display that allows for easy programming, monitoring, and adjustments. This enhanced control capability ensures that users can fine-tune their heating schedules according to their lifestyle, optimizing comfort while maintaining peak efficiency.

Reliability is a hallmark of the Munchkin brand. Built with high-quality materials, these boilers are engineered to withstand the rigors of daily operation, offering durable performance for years. Furthermore, Munchkin provides robust customer support and service options to assist homeowners and professionals alike.

In summary, the Munchkin Gas-Fired Hot Water Boiler stands out due to its modulating condensing technology, high efficiency, compact design, and advanced control system. These characteristics make it an excellent choice for those seeking a reliable, efficient, and versatile heating solution. Whether for residential or commercial use, the Munchkin boiler provides consistent, effective heating that meets the demands of today's energy-conscious consumers.