I have a Weil-McLain Ultra Series 2 -155 Gas Fired Water boiler furnace that has been installed for about a year. It started with hard lockouts, code E18 occurring about once ever week or two. It has gradually gotten worse with soft lockout code b30 acting as a hard lockout and not resetting. Now it has a shut down fault daily and sometimes several times in a day. The faults are usually either E18 or b30, but either one will shut the furnace down until the reset button is pressed. It then fires up normally and works fine until the next fault hits. I would appreciate ideas on a permanent fix for this problem.

I believe the Series 2 was discontinued some time ago. Weil McLain is not the only high efficiency new style boiler to have problems. My first suggestion is for you to make sure that the contractor that installed your boiler did so EXACTLY as the manual directed. Many faults and problems can be traced back to the install.

Since most if not all contractors warranty there work for at least a year I suggest you have them look into the situation if possible. The boiler and its operation are there responsibility. Here is a link to the discontinued boiler site for WM and all the information is posted for your unit that may be needed to allow them or you to check for proper install. Once that is completed then they can move on to making a permanent repair.

I take things one at a time and always look over the install before trying to figure out what is causing a failure.

It may also be necessary to reset or change the parameters which we always used a laptop computer and Gascom software.

Weil-McLain :: Weil-McLain :: Discontinued Boiler Literature

Also please post your start up and checkout sheet that was left at your site by the installer/service person that did the start up on your boiler when new. This way the flue temps,C0, and other items that could be causing a problem will be known to the board so we can better be able to help you out.

I have a feeling your problem is with the correct water flow through the boiler since it is locking on to high a water temp(thermal overrun (e18) and to high water temp out (b30= High Limit). It could be your piping system is not designed correctly or you have pump that is not doing its job.

DO NOT forget to post your start up and check out sheet.