mechanical v. electric probe type LWCO

steamfitter

On HW boilers, is there a preference on which type of LWCO there is?
Is there as much need to blow down the Mech LWCO on a HW boiler as there is on a Steam boiler?

EBEBRATT-Ed

On hot water I think most would recommend a probe type control.

No, hot water electronic probe controls need to be tested with the test switch which most have. The probe should be removed and cleaned 1 a year.

steamfitter

Why are mechanical LWCO not as common in hw boilers?
If they are used, would they have to be blown down as much as those on steam boilers?

JUGHNE

IMO they would be hard to test as you need the float to experience the water drop. So maybe never get blown down and tested.

EBEBRATT-Ed

Usually when you blow down a hot water mechanical lwco the water come into the float chamber faster than you can drain it so you can't test the control. McDonnell Miller makes (Used to make??) test & checks which were piped into the pipe tree so you could test the control