Utica SSC100 with Boilermate

Flick

I have a Utica SSC100 boiler with a indirect boilermate hot water heater and Taco 6 zone relay switch. The boilermate is acting up and calling for demand at 160 and is never satisfied unless I set it above 160. I changed the aquastat and getting the same results. The boiler is not set for DHW and is on a priority zone but I’ve tried it on other zones and getting the same thing.  Anyone have any ideas what could be wrong?

EdTheHeaterMan

is this the boilermate equipped with the analog thermostat or the digital thermostat?

how long has the system been in operation before the problem became an issue?

Trying to understand your situation...   does the water heater need to be adjusted to 160° to solve this issue?  OR  Does the water temperature in the water heater go to 160° even if you set the water heater temperature lower?

Finally. If the boiler limit is set at, say 155° and the water heater is set to 160° ... the boiler water is never going to be able to make the water hotter than 155°

Does that make sense?

Flick

EdTheHeaterMan said:

is this the boilermate equipped with the analog thermostat or the digital thermostat?

The boilermate has a analog aqua stat 

how long has the system been in operation before the problem became an issue?

the system is 7 years old, I changed the water last fall and it ran all winter without issues. The Utica internal circulator pump failed two weeks ago and contaminated the water with gasket pieces. Changed the pump flushed the system and now this is the only issue I’m still having. 

Trying to understand your situation...   does the water heater need to be adjusted to 160° to solve this issue?  OR  Does the water temperature in the water heater go to 160° even if you set the water heater temperature lower?

the water goes to 160° regardless of the setting. 

Finally. If the boiler limit is set at, say 155° and the water heater is set to 160° ... the boiler water is never going to be able to make the water hotter than 155°

boiler is set to 180°

Does that make sense?

HVACNUT

The Boilermate is or isn't wired to the Taco zone panel?
If wired into the boiler, try removing the low volt wires to the aquastat at the boiler. If the domestic demand stops, there's a short in the low volt wires, or the aquastat is incorrectly wired. What make and model aquastat?
If the domestic demand doesn't drop out, then go over the programming and make sure nothing changed. 
If all is good with settings and wiring, then its internal in the boilers control board. 

Zman

This would be way easier if the Boilermate was controlled by the boiler with DHW priority. I assume that is not an option at this point?
From your description, I can't tell if you are referring to the DHW temp setpoint on the boilermaker or the boiler output setpoint. Could you clarify?
In general, Boilermates have fairly small heat exchangers and are additionally prone to scaling. Usually folks set the DHW temp in the 120-130 range. It is not at all surprising if the boiler is unable to satisfy the load when set to an output temp of < 160.

Did you change the circulator with and identical one? Pumping in same direction?

Flick

Thanks for everyone’s input. It was a bad flame sensor but it never tripped any codes.