Wiring a pressuretrol

EZPassGas

I have a gas steam boiler that has a pressure trol an automatic water feeder a low water cutoff and a switch flue damper. A new pressuretrol switch was put in last winter (L404F). The pressuretrol does not shut the boiler down when it reaches pressure the only way the boiler shuts down now is when the low water cutoff switch kicks in. Does anybody have a wiring schematic as to how these items should be wired in conjunction with each other. I know right off the bat the pressuretrol is in properly wired because the hot wire is wired to the thermostat. I can provide pictures and model numbers for anything. Thank you for your help.

Jamie Hall

The pressuretrol and the LWCO must be wired in series. Whether they are 120 or 24 depends on how your system is set up, but in either case they must interrupt power to the burners and turn the boiler off. The thermostat could also be in series with them.

Fred

Before you go messing with the wiring, when is the last time the pigtail (looped pipe) that the Pressuretrol is mounted on taken off and cleaned out? They get clogged and the Pressuretrol can't see the pressure to shut the boiler down. That can happen in a year, especially if it is mounted on a tapping off of the LWCO. Post a couple pictures.

EBEBRATT-Ed

need pictures, model of lo water cut off and feeder at minimum

HVACNUT

Not sure what the F designates. Is it a Honeywell? Should be a P404A.

HVACNUT

Not sure what the F designates. Is it a Honeywell?
A P404A is the norm.

JUGHNE

Why was the new control installed?
Are you sure the pigtail was cleaned or changed at that time?

EZPassGas

I have VTX24 feeder, a McDonnell LWCO, a Field Control GVD-6 flue damper, an Honeywell L404F Pressure-trol, (F is non mercury, has a snap switch) and a Honeywell RTH6350D1000 Tsat using white and red wires only

EZPassGas

Oh and it's a Dunkirk PVSB 4D NG boiler

Fred

That's the wrong Pressuretrol. There are 12 models of the L404F, ten of them have a cut-in pressure range from 5PSI up to a cut out of up to about 150PSI. There are 2 models that have a cut-in of 2PSI with a Cut-out of 15 PSI, still way too high to ever shut the boiler down on pressure..

EZPassGas

Honeywell's website says it's one PSI to 8 PSI L404F1367

EZPassGas

And Fred to answer your other question yes the pigtail is clean I cleaned it out today

Fred

Even from 1 to 8 PSI, it will never shut the boiler down on pressure. the "1" is Cut-in which means it will allow the boiler to start up at 1 PSI or less,but it will never cut out if your boiler pressure never reaches the Cut-Out setting. It is the wrong Pressuretrol, still.

Fred

That model Honeywell has been discontinued and it is 2PSI to 15PSI. It does say it had an operating range of 1 to 8 PSI but it is Wrong:
http://www.supplyhouse.com/Honeywell-L404F1367-Pressuretrol-Controller-w-Auto-recycle-2-psi-to-15-psi

HVACNUT

@Fred. I'm out of the loop a little bit I guess. The PA404A is no longer available? Doesn't the "A" designate break on pressure rise? What's this "F" stuff?

EZPassGas

Well if I have to get a new pressure troll then now's the time what would you suggest?

Fred

This is the typical Pressuretrol, set at .5PSI Cut-in and a differential of "1" for a total Cut-out Pressure of 1.5PSI:
http://www.supplyhouse.com/Honeywell-PA404A1033-Pressuretrol-1741000-p

EZPassGas

And then if somebody could just paint me a picture.....where does the red thermostat wire go where does the white thermostat wire go. Where does B & R on the pressuretrol go. Where does the Orange from the damper go

Fred

@HVACNUT , yes you are correct. The OP posted that his Pressuretrol was not wired right because it never shut his boiler down on pressure. It was installed last year. Well, it is the wrong Pressuretrol. It should be a 404A. From what I can gather, the "F" is some kind of Recycle" feature but the unit he has isn't even in the pressure range it should be for a residential steam boiler.

EZPassGas

Thats good to know I paid several hundred dollars for the wrong equipment to be installed

Alan Welch

A pressuretrol is a switch,. If you separate one of the connections on the wire going to it , or remove one of the wires under the screw terminal and the burner still runs then it is wired wrong.