utica boiler

don_9

Model number ub90-125.The problem we are having is it is locking out .

I arrive to find the stack pipe never poke.Several other company has been out replace pressure switch,clean out,the drain and then threw there hands up.understandable.lol

Ran test and found it to be burning great.o2,,stack temps,,co and co2 was 7.4 tech rep wanted to see 8.5 done with adjustment on valve.Also connected Manometer and checked pressure switches all is well.The boiler is not being taking out on any safety that i can see.However doing my visit i watch the unit running and then stop and would go back into a prepurge mode.and  then fired up again but the water temps never reach high limit yet.Then once i watch it go into prepurge mode and not come out of that mode unless i killed power and back on.

I pulled the buner and flush out the hx as the tech rep suggested.got alittle color of water out of it but not much before it went cleared.My thought its the board however the motor on the burner sounds noise as heck like it on it way out.I suggested replacment on the board and the inducer bc of the noise.

I sure hate becoming a part replacer.Have any of you gentleman ever run into this issue on this boiler? Boiler was install in 07.and customer claim he had has had this problem all along.And him and the installing contractor had a falling out.Would be nice to hear the other side of the story but one learn to digress.lol

Tia

Tim McElwain

Does this boiler

have the United Technology board 1013-10 Integrated Boiler Control? If so what are the flash codes on the board when failure occurs?



Do you have the manual for the boiler?

Paul48

Just

looked at the manual, and the boiler would appear to be in pre-purge,when actually it might just be waiting for the pressure switch to be activated (up to 5 minutes).As Tim said, the only way to know what the boiler is actually seeing, or waiting for, is to follow the sequence of operation through the indicator lights.No un-necessary parts changing.

don_9

board

Hi Tim.Yes it does have the board u speak of.And yes i watch the lights.it work normal for the most part but i watch it go from main flame and shut down back on into prepurge but would never come out of prepure unless i kill the power,.pressure switches were change out by another company.

I do have the manual for the boiler and it directs me to a bad board after going thru all the steps.

Thanks all

Tim McElwain

Before you condemn

the board do a manometer check of the pressure differential on the pressure switches. The procedure for that is on page 42 in the manual along with differential pressure which for your unit is 1.00" W.C. There are two switches one is Normally closed and set at 3.5" W.C. the other is normally open set at 0.5" W.C.



Also read Blocked Vent Safety Shutoff on page 21 full paragraph. The pressure switches can take as long as 5 minutes to make in some cases.



This could also be a case of the unit going into post purge on shut down and not going back to a restart unless the power is interrupted in that case it is the board.

don_9

The board

Thanks Timmie.Found the problem after sitting there for a half of day.The board was keeping in the inducer motor, even after the call for heat was over at the tt terminal..Tap the board and the inducer went off.so it was seeing reverse on the pressure swtiches and would not come out of prepurge.

I will say this is one of the best burning boiler i seem as of late when it comes to all the combustion numbers.

Tim McElwain

Both the older

Honeywell Board  and the UTEC boards are known for the time delay relay for post purge to stick.