Weil Mclain WM97 Auto Reset Domestic

apanek01

On a Weil Mclain WM97 +70 boiler, it Auto Reset's with status Domestic on occasion. The boiler is heating an indirect hot water tank and 2 zone baseboard heat. Diagnostic error codes:

1/21/22 3:43 PM
Status : Domestic

Manual Rest: None
Auto Reset: Yes

Input 1: ON
Input 2: OFF
Input 3: OFF

Manual Limit: CLOSED
Auto Limit : CLOSED
Low Water Cut-off: CLOSED

Blower: 1341 RPM
Flame Signal: 0

Gas Valve: On

Boiler Circulator: OFF
Circulator 1: ON
Circulator 2: OFF
Circulator 3: OFF

Blower: 87%
Alarm: OFF

Boiler Out 1: 168
Boiler Out 2: 169
Boiler In: 159
Flue 1: 144
Flue 2: 144
Outdoor Reset: None

HVACNUT

Those aren't error codes.
It looks like those numbers are when the boiler just completed a cycle and was in post purge. 9 or 10 degree Delta T, flue temp 144°.
Is there an actual error code?

Matt_67

Flame signal 0 with the gas valve on - either lost flame or wasn’t sensing it. I’d start by looking at flame sensor.

apanek01

This model boiler does not produce error codes. When you go into the contractor menu by holding the update and down arrow keys on the front panel it records the last 3 lock-outs and provides the detailed information above. I don't think the boiler was in post purge yet as it records that in the status. It appears while it was heating DHW it all the sudden got a reading of no flame from the sensor I am suspecting, the blower was running and gas valve on - thanks Matt_67 as you gave me some ideas.

I found this thread here that might point to root cause?

https://www.doityourself.com/forum/boilers-home-heating-steam-hot-water-systems/590061-flame-fault-error-weil-mclain-wm97.html

Wayland Zheng reported "caused by a MELTED BURNER GASKET. I was told that there is a design flaw which cause the gasket to melt after using it for a while. When it melts, it fails to let that part of the boiler grounded properly (that's what i've been told. No idea why that will affect my flame signals). The solution just go online and find the gasket and replace it..."

I also have this issue posted here that might be related?

https://forum.heatinghelp.com/discussion/186426/weil-mclain-wm97-taco-lwco-fail-every-few-months#latest

apanek01

The MELTED BURNNER GASKET issue only affects the WM97+ 155 - the largest BTU in the series. I have the WM97+ 70, the smallest one in the series.

Here is the a link to Technical Bulletin on the issue for the WM97+ 155 for reference:

https://www.weil-mclain.com/download/file/fid/3021