New Hope for Standard Pressuretrol?? (and a warning)

jpf321

I was working on my neighbors system over the last few days .. I managed to dial in the "standard" pressuretrol to cut-out at 0.8psi and cut-in at 0.1psi .. there is a very small calibration hex-screw inside which I was able to adjust with a needlenose pliers. The screw lives between the see-saw and the diaphram. It is adjustable from above the see-saw. (At least in the unit I had in my hands)



Another thing I learned about the standard pressuretrol .. if you adjust them all the way down .. they effectively "lock-off" .. the adjusting screw puts downward pressure on the spring and in turn depresses the microswitch .. <span style="color:#FF0000">so a word of warning when blindly cranking the pressuretrol all the way down .. you've got to have a little bit of tension on the spring NOT compression. </span>

gerry gill

good man..

i like it when people arn't afraid to 'tweak' things..which model were you working on?

jpf321

it was the standard 0.5-9psi

it was the standard 0.5-9psi grey pressuretrol ... which according to the boiler service tag was installed last June ... it had a microswitch not mercury .. i don't have the exact specs but the 404A type. wait until you see the pictures of the rad vents which "exploded"



funny thing about the boiler service tag ..

entry 1 -- chk ok

entry 2 -- seasonal check ok

entry 3 -- 6/25/09 -- installed pressuretrol

entry 4 -- jpf -- 4/2/10 -- cleaned pigtail, calibrated pressuretrol, Ct-Ot=0.8psi Ct-In=0.1psi, inspected LWCO probe, drained + flushed, installed low-pressure-gauge, installed Hoffman 75 main-vent.