Honeywell L404F1060 Pressuretrol Controller Shutting Down Boiler: Help Needed

FireItUp

I'm a super and with the very cold weather we're experiencing now, the building's Honeywell L404 keeps shutting down the steam boiler after each long cycle when the boiler builds pressure and I have to manually reset it for the boiler to come back on which is keeping me running back and forth. We also have a Pressuretrol PA-404 and I'm guessing there's some conflict between the settings on them. If I basically want the boiler to shut down at roughly 3PSI and come back on at .5 PSI, what should the settings be on the L404 and the PA-404? (We also have a separate Honeywell Pressure high limit control with the red reset button, but that's not an issue here.) Thank you pros for any help.

LRCCBJ

First question:

Why are you using an L404 and a PA-404 in series?

The L404 is the only operating device that you require and IT WILL SHUTDOWN ON PRESSURE BASED UPON HOW YOU SET IT. 3 PSI is a bit much…………….2 PSI would be recommended.

You do have the lockout limit control as the second device…………which is the safety.

FireItUp

I don't know why both the L404 and the PA-404 are both there. Normally when it's warmer out and the thermostat shuts down the boiler sooner (and not any pressure control), this problem doesn't occur. It's only when it's VERY cold out and the boiler is running for much longer times and builds higher pressure that this issue surfaces. Ignoring the PA-404 for the moment, why am I being forced to reset the L-404 manually?

LRCCBJ

IF the PA-404 is not doing the shutdown:

When a boiler runs for an extended time, in this cold weather, if eventually fills all the radiators in the system. With a properly sized boiler, this rarely occurs. You are experiencing a rare occurrence. Once the system is filled, the only thing that can occur is for the pressure to rise. The L404 sees this rise and, at the setpoint you selected, it shuts down the boiler.

This is normal!

After one minute………..or less………….the pressure will drop below the L404 limit and the boiler will restart.

This is normal!

This cycle will continue until the 'stat is satisfied.

It might shutdown and restart 5-7 times in really cold weather.

This is normal!

DO NOT BE CONCERNED WITH ANY KIND OF RESET. THE BOILER HAS IT COVERED!

I do think you should bypass the PA-404. A worthless control installed by a less than competent individual.

FireItUp

Sorry, I have to disagree. Once the L-404 shuts the system down, it absolutely will not come back on once the pressure drops. The boiler will stay off for hours until and only until I manually reset it. I'm not trying to argue, just clarifying what's going on here.

LRCCBJ

Understood.

Take the L-404 off of whatever pipe is connecting it to the boiler (presumably a pigtail) and thoroughly clean it out.

The situation you described tells that the L-404 is not seeing the actual pressure in the boiler………..or……….the L404 has failed………..which I seriously doubt.

FireItUp

OK. Will replace the pigtail. Thank you!!

LRCCBJ

One other possibility:

The PA404 could also have a clogged pigtail.

Since you don't need the PA 404, just raise the slider switch up to 10. That will PREVENT it from doing anything with the exception of an emergency…………and that is covered by the manual reset pressuretrol.

LRCCBJ

You don't need to replace it. Just blow it out with compressed air! Be sure it is not connected to either the boiler or the pressuretrol when you do this.

mattmia2

Probably a commercial building, the manual reset secondary pressuretrol is usually required in commercial buildings. Check that the pigtail to the operating pressuretrol is clean. Pictures? Is the operating and safety control on separate pigtails or other water seals?

LRCCBJ

https://forum.heatinghelp.com/discussion/comment/1833002#Comment_1833002

He also has that Matt.

The PA 404 is superflous.

Jamie Hall

Whether the PA404 is superfluous or not is quite irrelevant. Leave it in the circuit — but check and clear all three (I hope) pigtails.

Then, if that doesn't help, check the settings on the L404 and the PA404. One of them (I'd pick the L404) should be used as the pressure control device. The other (I'd pick the PA404) would be an automatic reset safety device — and the manual reset control (you don't specifiy what it is) would be the backup safety. If this is the desired arrangement, I'd set the L404 main scale for the desired maximum running pressure — 3 psig seems a bit high. and I'd try it at 2 psig, but your system may need more. I'd set the differential (which is subtractive) to 1 psig in either case. Then I'd set the PA404 main scale to 5 psig and it's differential (which is additive) to 1 psig. With these settings, the PA404 should never operate; it's a safety, and the L404 will be controlling. I'd set the manual reset to something reasonable — say 8 psig.

LRCCBJ

There is absolutely no justification for the L404, the PA404 and the manual reset pressuretrol. Just get rid of the the PA 404. One less control to screw up the entire affair and make judgments that are related to it. It's a difficult control to be sure of its setpoint in any case.

EBEBRATT-Ed

@Fireitup See @Gordo videos on you tube. Silent Steam Team. He says the L404A is NG & I agree. Set that up high and use the PA404A.

You adjust the cut in on the main scale of the PA404A with a screwdriver. The cut in is when the burner starts. Take the cover off and set the differential at 1-2 psi on the white wheel.

Make sure all pigtails and related piping into the boiler are clean and clear.

keep in mind that all Honeywell pressure controls have an inaccurate scale. You could have a partially plugged pigtail on the L404A

FireItUp

To all who answered, many thanks. I replaced the pigtail and the system is working fine now.

LRCCBJ

Excellent.

This was a simple fix.😁