Pressuretrol cut-in/out accuracy

Ken L.

Al,

In my case (5 psi before the pressuretrol cuts out, set at 1 +/-1 psi by the plumber) my boiler is a brand new Peerless 63-03.

I used to work for a calibration company and could have the gauge checked for accuracy.

As I understand the physics of it, the loop in the pigtail holds some water which makes the pressure lag somewhat. The pressure gauge is on the boiler, not the pressuretrol.

I'm OK with the operation if this is normally how it works.

Thanks!

Ken

Dave_4

Pressuretrol cut-in/out accuracy

I just cleaned out a very clogged pressuretrol pigtail on my one-pipe steam system (it wasn't cutting in at all). It's a Burnham boiler, installed in ~1998, with a Honeywell PA404A1009 pressuretrol. The pressuretrol is set to 0.5 cut-in with a 1 psi positive differential, so I should see it cycling up to ~1.5psi, and then back to ~0.5psi, right? Watching the pressure gauge, I'm seeing it cut-in at ~1.25psi, and cut-out at ~2psi. The pressure gauge is mounted on a separate knock-out from the pigtail.

Is this normal to see such a difference from what I've set it to (maybe 1/2 to 3/4 psi off)? I'm not sure how accurate the pressuretrol settings are supposed to be. Also, I've never really paid too much attention to the high/low cutoff points before now, so I have no idea what it was working like in the past (although the pigtail was *SO* clogged I'm not sure what I would have made of the comparison). When the thermostat is calling for heat, the boiler is on ~3min, and off ~30sec. Does this sound correct?

Thanks in advance...

Ken L.

similar question

My boiler was set to 1 psi with 1 psi differential. I watch the pressure gauge on the boiler raise to 5 psi before the boiler cuts off. I tapped the pressuretrol once to immediately see the boiler cut off (not sure if this was a coincidence or not).

So the question is: Should the pressures on the boiler pressure gauge match the pressertrol setting?

Jerome_3

pressuretrols

I can't find a pressuretrol for my residential one-pipe steam system that is sensitive enough to yield the low pressures recommended in "The Lost Art of Steam Heating." my guage reads at least 3.5 lbs cut-out even when the pressuretrol is at its lowest setting (.5 in and 1 lb differential) where can I get a more delicate pressuretrol?

Al Letellier_9

pressuretrol

It is very difficult to find any pressure gauge sensitive or accurate enough to read exactly what the pressuretro is set at, and it is impossible to be very accurate with the scale on the pressuretrol. Don't get too hung up about it. What you describe happens on most steam systems. If it's working, don't fix it.

Al Letellier_9

readings

Yes the gauge should read Approxiamately what the pressuretrol is set at. Sounds like you pigtail is plugging up. Get it cleaned.

Al Letellier_9

sensitive pressuretrol

You can get a vaporstat that will lower the pressure, but all three of these posts have the same moral to the story. The gauges just don't stand up and are rarely accurate. Trust the control first. change the gauge and if the readings are still high, the pigtail is plugged or the pressuretrol is going bad. It does happen but I would always check/replace the gauge first.

jim_110

I had a new Peerless and the stock gauge was garbage from the gitgo. To all of you clean the pigtail and better yet replace it with a brass one.Clean the base hole of the pressuretrol. Then run a 1/4 inch tee and nipple off the base of the pigtail so the control and gauge are sharing the same pressure reading.I have a Marshalltown gauge that reads from 1 to 60 ozs max which reads my 5oz cutin and 24oz cutout on the button.Google Marshalltown and give them a call worth the money.Also leave the gauge that reads 30lbs max installed on the boiler IT'S CODE.

Jerome_3

but what kind of pressuretrol allows for your settings of 5oz and 24 oz?