pressuretrol honeywell PA404A 1033 -- can't get low

Steven Todd

Hello.
I have a new-ish Honeywell pressuretrol (pa404a 1033, subtractive) whose specs state a range from .5-9#, with a differential of 1-5#, BUT the system runs between 2.25 (cut-in) and 3.25# (cut-out). I've undone the set-point screw as far as it can go without it falling out of the tension spring. Any ideas how I can get the pressuretrol to run between .5 (cut-in) and 1.5 (cut-out)? Many thanks.

Unknown

It never will

That control is basiclly a high limit, a back-up control to the operating control; in this case, the thermostat.

You can ADD a control that is that fine, if your boiler is so big that the pressure starts to climb before the thermostat satisfies.

You can have it wired in series with the thermostat, so that you still have a BACK-UP high limit control, or you can replace the LIMIT CONTROL with a vaporstat, and still use the thermostat as the operating control.

Since all systems are different, no operating pressure control is selected for a steam boiler. The high limit is there to prevent a runaway boiler, in the event your operating control fails, but YOU select the operating control at the same time the boiler is selected.

In your case, only a thermostat was selected. You'll need to add an operating control (vaporstat) if you wish to operate the boiler by pressure, rather than room temperature.

That pressuretrol that you backed the screw out of should now be inspected for proper operation, before you run the boiler unattended.

It might NOW only have a thermostat to protect you from danger.

Noel

will smith_2

pressuretrol

You would be better off using the control you have now as a paperweight for your boiler maintenance log. Get yourself a vaporstat (as previously mentioned), along with a manual reset pressuretrol with a cutout set at 15#.

Firedragon_4

Yeah,

replace it with an L408A vaporstat. We'll cover that on Thursday in Baltimore at the Oil Heat Cares extravaganza.

oil-2-4-6-gas

.Bill@honeywell

why does Honeywell even still sell that pressuretrol--it can't be set low enough for most residential units,they aren't that accurate --and they have no use in commercial applications

Steven Todd

Thank you


Thank you gentelmen - a paperweight it will become. (In the meantime, the adjustment screw is well attached and the pressuretrol is regulating the boiler, but thanks for the warning/pointer Noel.)

BillW@honeywell

You can replace...

it with an L404. What products are made are far outside my baliwick, but my guess would be that the OEM's want them. I also prefer the L404. Thanks, Noel for the explanation.