Weil McLain Ultra 155 Lockout [9 Easy Solutions]

Weil McLain Ultra 155 lockout takes place when an error occurs. The error message will be visible on your display when it happens. There are two types of lockout errors. One type is soft lockout error which will cause your heater to reset automatically. The other is hard lockouts. In that case, you will need to reset the water heater manually.

Read our Weil Mclain Ultra 155 lockout guide to know what to do during each lockout code.

Weil McLain Ultra 155 Lockout [9 Easy Solutions]

In this section, we will take a look at the most common Weil Mclain Ultra lockout codes. We will also explore the simple and easy solutions for each error. Let’s first take a look at the soft lockout codes and then we will check out the hard lockout codes. 

Note: You can also read how to fix Weil McLain ultra boiler problems.

Weil McLain Ultra 155 Soft Lockout Codes

The most common Weil McLain Ultra lockout codes that cause the water heater to auto-reset are explored below.

1. Weil McLain Ultra E18

The error code 18 takes place only when the heat demand is less than the lowest fire rate of the boiler. The system will reset automatically. 

Solution:

Should the error code come back try the following steps to get rid of it.

  • Make sure that the boiler and the system are both full of water.
  • Verify that there is no trapped air in the system that is obstructing appropriate flow.
  • Examine and confirm the piping and components of the system (including pipe size and circulator capacity).
  • Check that the plumbing follows the boiler’s manual’s recommendations.
  • Inspect that the circulator(s) are working properly.
  • A loose connector on the boiler outlet sensor is a possibility. Connectors should be tightened.
  • A faulty boiler supply outlet sensor is a possibility.

2. Weil McLain Ultra E19

When the return water is higher than 203 °F in temperature, this error code will occur. 

Solution:

To fix this error code performs the following actions-

  • Check whether the water flowing through the boiler is going in the right direction.
  • Make sure that the boiler and the system are both full of water.
  • Ensure that there is no trapped air in the system that is obstructing appropriate flow.
  • Inspect and test the pipework and components of the system.
  • Verify that the plumbing follows the boiler’s manual’s recommendations.
  • Examine that the circulator(s) are working properly.
  • A loose connector on the boiler outlet sensor is a possibility. Connectors should be tightened.
  • A faulty boiler supply outlet sensor is a possibility. Replace if needed.

3. Weil McLain Ultra E24

This error code means that the return temperature of the water is higher than the supply temperature. The burner turns off till the supply water temperature becomes higher.

Solution:

You should take the same actions as we mentioned for Error code 19 or E19.

4. Weil McLain Ultra E25

When you can spot error code 25 on your display it means that the outlet water temp rose too quickly. In this case, the burner turns off for 10 minutes. The burner will recycle, increasing the wait 1 minute on each attempt, and continue reattempting till a max of 15 minutes.

Solution:

Take the following steps to get rid of E25.

  • Ensure that hot water from the DHW tank doesn’t return.
  • Make that there is no trapped air in the system that is obstructing appropriate flow.
  • Inspect and test the pipework and components of the system.
  • Check that the circulator(s) are working properly.
  • A loose connector on the boiler outlet sensor is a possibility. Connectors should be tightened.
  • A faulty boiler supply outlet sensor is a possibility. You may need to replace it. 

5. Weil McLain Ultra E65

This error code means that the water heater is waiting for the blower to start.

Solution:

You can correct this error by doing the following.

  • Switch the display to info mode/ If INFO #6 shows 6._32, that means the blower has failed. Replace the blower.
  • Check for 120 VAC on the high voltage connector on the blower wiring; if there isn’t any, inspect and replace the wire harness or control module.

Weil McLain Ultra 155 Hard Lockout Codes

Let’s take a look at the most common hard lockout error codes.

6. Weil McLain Ultra E00

When your water heater can detect flame on startup, this error code will pop up on the display. It can be caused by-

  • A cracked igniter.
  • Incorrect combustion results in an extremely hot burner.

Solution:

After the boiler has been turned off, look inside the burner inspection window. If the flame persists, the gas valve may be leaking. The gas valve should be replaced. Check the gas line pressure coming into the boiler before replacing the valve. Valve damage can occur if the pressure exceeds 13 inches w.c.

7. Weil McLain Ultra E03

This error code comes up when ignition failure happens or there is an electrical issue with the gas valve.

Solution:

If an error occurs before the boiler attempts to ignite, the issue could be with the gas valve connection or harness. Using the connector’s outer two pins, check the gas valve harness for continuity. 

Measure the resistance between the gas valve’s outer two pins; it should be around 50 ohms. Each pin’s resistance to the ground must be infinite. Replace the gas valve if needed.

8. Weil McLain Ultra E04

Error code 04 means that the voltage is lost after lockout occurred or AC voltage fluctuations on incoming power. If power is interrupted when another fault is present, or if power input fluctuations occur, code 04 is shown.  

Solution:

Install Weil-McLain part number 383-500-021, Time Delay Relay (3 minute incoming power time delay) to provide incoming power time to stabilize before powering the boiler to reduce shutdowns due to bad power conditions.

Time Delay Relay may not be able to solve E-04 in extreme circumstances of power fluctuations. If this is the case, a good incoming power line filter or an Uninterruptible Power Source (UPS) may be able to help.

9. Weil McLain Ultra E30

This error number appears when the temperature in the boiler increases above 58° F. The temperature rise through the boiler should be less than 35° F.

Solution:

Here are the things you can try to solve this issue.

  • Make that there is no trapped air in the system that is obstructing appropriate flow.
  • Inspect and test the pipework and components of the system.
  • Check that the plumbing follows the boiler’s manual’s recommendations.
  • Check that the circulator(s) are working properly.
  • It’s possible that the boiler supply/return sensor has loose links. Connectors should be tightened.
  • A faulty supply/return sensor is a possibility.

How To Manually Reset Weil McLain Ultra 155?

It is a simple process. Follow the instructions below to reset the water heater manually:

  1. The status will change to LOCKOUT when Weil McLain Ultra 155 error codes occur. The Time & Date line will alternate with the Error message. On the Homeowner screen, the line MANUAL RESET will display.
  2. To reset the fault condition, select MANUAL RESET.
  3. The MANUAL RESET screen will show whether the issue was a manual or automatic reset, as well as the fault name, time, and date.

FAQs:

How long do Weil-McLain boilers last?

They should endure at least 15 years or longer if properly maintained. Commercial boilers have a 10-year non-prorated heat exchanger guarantee, while residential boilers have a 12-year non-prorated heat exchanger warranty and both categories have a two-year components warranty.

How do I know if the pilot light is out on my water heater?

You can remove the screen with a screwdriver and take a peek inside. If you are able to see the pilot light, you know it is on. In case the flame isn’t visible, the pilot is off.

How often should a boiler be serviced?

Your boiler should be serviced at least once a year to ensure that it is operating safely and effectively. Failures, higher energy bills, and an early warranty termination could all result from not getting your boiler serviced.

How do you adjust the temperature on a Weil McLain ultra boiler?

Press the setting dial. Enter the Temperature setting mode. You will see that the display has either ‘OFF’ showing on it or the current temperature. You just need to turn the dial to set your desired temperature for water heating.

What temperature should a Weil Mclain boiler be set at?

For a forced hot water system, the usual setting for the aquastat (the temperature control mechanism on a boiler) is 180°F. In the event of severe weather, it can be elevated to 210°F.

Conclusion

As your water heater gets older you’ll experience lockouts more frequently. It is a normal thing. As long as you properly maintain your water heater, you don’t have to be too worried about lockouts. 

But in case your water heater is new and you are getting errors very often, it is best to call in a professional to make sure there isn’t a serious issue.

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