aquastat relay

jaybee

I dont fully understnd the operation of the cold star relay8148. I almost change one today that didnt need to be changed.Well, i made sure ther was a call for heat and then about 10 seconds later the relay clicked in but the burner did not fire. So i got my meter out and saw power to L1,L2 and power to circulator,but no power at the burner circut.NOw the aquastat was set at 180 and the temp of the boiler was 170. A while later the burner fired ,now could it be that the boiler would not fire because the temp wasnt cold enough or what? Man someone please respond.

Weezbo

on a weil mclain?

the call for heat opens the zone valves and rolls some heat out the pipe via the circulator...when the boiler cools down...the recirc bags off a while and lets the burner catch back up... ok so you have no zones and lots of recircs they on go boiler bangs in the heat and goes off when it has reached its high limit...and doesnt go again until the boiler cools down 20 degrees or so...then if it should fire after the recircs shut down then it fires to its high limit the temps continue to rise and the water expands into the expansion tank.

jaybee

Thanks wezbo!!!

Rookie_3

Aquastat

Works like Weesbo said but I beleive the 8148 has only a 10*
differential. Should you want a 20* drop before the system fires again you can use a L4006-A high limit with a 845 relays for each zone.