Weil Mclain Ultra 105 - b25 code

blee

I recently did a maintenance kit on my Ultra 105,
About a day or two later I started getting a b25 error message. It came and went, but every few days it showed up more frequently over the course of the last 2 weeks. Now I woke up this morning and the boiler wont stay on for more than a few minutes and is constantly showing the b25 code

Any ideas?
I'm a newbie, so I don't know any technical terms or abbreviations

blee

(This is what I've found so far in the Weil Mclain Manual)

FIRED WATER BOILER SERIES 1 & 2

Instructions in this supplement are based
on factory default parameter settings.

SOFT LOCKOUT
[Display flashes 9, then b in first position; last two digits on steady (code)]

25
Outlet water temp rose too quickly - burner off for 10 minute wait (burner recycles, increasing wait 1 minute each attempt, to a max of 15 minutes)

1 - Possible hot water return from DHW tank.
2- Make sure system does not have trapped air preventing proper flow.
3 - Inspect and verify system piping and components.
4 - Verify piping agrees with boiler manual recommendations.
5 - Verify proper circulator(s) operation.
6 - Possible loose connector on boiler outlet sensor. Tighten connector.
7 - Possible bad boiler supply outlet sensor

blee

Another thing I noticed, when doing the maintenance kit, the cover plate that is supposed to be torqued to 50 inch lbs was hand tight. I took 7 of the 10 nuts off by hand which was kind of odd. When I re-installed the cover plate I torqued them to 50 inch lbs

blee

Now it is throwing an E 36 code as well

"Outlet water temperature sensor open circuit"

1. Inspect outlet water temperature sensor and wiring.
-Replace sensor if wiring correct and in good condition.
-Replace low voltage wiring harness if problem persists.
-Replace control module if harness replacement doesn’t resolve

DZoro

Make sure all the connections that may have been disconnected are back in their proper places.
Especially those two sensor wires.
D

Tom_133

You probably broke the supply sensor, easy to do. They are cheap and available. Oh and you dont need to drain they just screw in.

HVACNUT

New sensors should have come with the maintenance kit. If it worked before you worked on it, then Occam's razor.

GW

HVACNUT said:

New sensors should have come with the maintenance kit. If it worked before you worked on it, then Occam's razor.

what may I ask is Occam's razor?

This is always a fine line-------"it worked before you came to do the maintenance...."

Tom_133

HVACNUT,

I have never seen the sensors come in any kit. I could be wrong though happens all the time.

383-500-300 thats the supply and return sensor part number.

blee

Well, I was searching for b25 error code because my boiler was throwing this code again. First result from google was this thread I originally created, lol. 

 Thanks everyone for your replies! 

Also thanks to Tom_133, I just ordered a 383-500-300. Mine is falling apart and splitting in 2, after I seen this thread I went over to the boiler and pressed down on the sensor and the plastic cover snapped back in place and the boiler is up and running again.

I was just about ready to start firing up some electric heaters 😅