Utica UB95M-200 power issues

worldclasshvac

Have a new customer with one of these. Last year we did a new circ pump and dealt with an error code that we called into Utica for. External limit was being tripped and we resolved it. It has the newer control and we went thru basics with Utica tech along with combustion analysis and setup. Fast forward to this week with very cold temps. Customer complains it's not keeping up. Send my one of my guys out he babysits it 2 hrs no issues went over it pretty well. Finally got HO to watch it and it blanks out randomly. Could go days sometimes hours and screen blanks. They cycle power and it usually comes on. Last night it would not and letting it sit a half hour got it back online. Runs smooth and operates properly when it runs. We aren't there when it blanks out in the screen and they haven't seen an error code. I did print out the service manual for Monday. Other than the LWCO check and outdoor sensor check is anything glitchy with these things that someone with experience can point me to? Appreciate any pointers in advance we haven't worked on one other than this. Thank you

worldclasshvac

Following this up for others. I went thru the boiler and did a full check following the installation manual. I got to the setup part that referenced the line monitor and the proper adjustment. Incoming voltage is 121volts it was set to the 115 click not the 120. Adjusting it and finishing the setup with a slight adjustment off the combustion analysis solved the screen going blank issue

109A_5

Hello worldclasshvac,

Apparently the ICM491 (obsolete model) changes the state of a relay which seems to cause the boiler to shut down. Its in the Utica UB95M-200 manual but not really well documented to my satisfaction. I guess you would have to assume that "the boiler will restart" means it caused the boiler to shut down.

12 % over 115 VAC = 128.8 VAC it would not surprise me if something else may be going on at that location. The 121 VAC you were seeing going to 128.8 VAC seems like a lot to me. Maybe normal for that neighborhood or large loads are being switched on an off.

https://uticaboilers.com/wp-content/uploads/2022/02/1846.pdf