Pressure cut out faulty?

MikeMan134

Hi all,
was just checking in on my boiler and noticed the pressure was much too high. I recently adjusted the ptrol to be basically as low as it can go, as seen here. I've never noticed the pressure to be this high, it usually cuts out closer to 2 on the gauge (which is why I lowered the differential in the first place). Is this a faulty ptrol or some other problem?

bburd

Your differential should be set to 1 rather than 1.5. However, the more likely cause is clogging of the pigtail between the pressuretrol and the boiler, or the hole where it connects. The pressuretrol cannot react to boiler pressure if it cannot "see" it.

if you clean it yourself, be sure to put some water in the pigtail before reassembly to keep steam away from the pressuretrol. You would be wise to replace that steel pigtail with a brass one which is less subject to clogging.

EBEBRATT-Ed

Or you could just have a bad pressure gauge. But if the pigtail has not been serviced it should be

MikeMan134

I typically have it at 1 psi, I had jiggled it a bit to see if it was stuck and didn't reset it before the picture.. I'll try cleaning it out to see if that helps. It seems like it only went that high on the one cycle, strange...

Thanks for the tip.

ScottSecor

In a pinch, a pipe cleaner or cable tie might clear a clogged pigtail. We see them clog often, especially when installed like yours on top of a McDonnel& Miller #67. Be careful with that 1/4" steel street elbow, they clog easily too.

MikeMan134

So it's been a while. I have since checked the pigtail and it was clear. Too bad, no easy fix. I double checked the wiring for the pressuretrol and the boiler shuts off as expected when it is disconnected.

I set the screw as low as it could possibly go before it completely unscrews just in case the indicator was misaligned. Pressure still climbs too high and pipes are banging like crazy.

One thought I had, does the ptrol need to be above the water line? Right now the bottom of the ptrol is pretty close to where I normally keep it. I could extend the pigtail up a few inches.

I'm getting ready to replace the unit unless there are any other ideas.

EBEBRATT-Ed

It is better to keep the control above the water line at least 6" or so but it probably does not affect the operation. Helps keep gunk out of the control. brass fitting hold up better than steel and don't plug as easily.

Waher

https://www.youtube.com/watch?v=GgpRjlR-sCg

neilc

does your gage return to 0(zero) when the boiler has been off a while?

and did you actually blow thru the pigtail as it's attached to the LWCO?
that 90, and or the LWCO casting port might be gunked also,

MikeMan134

The gauge does return all the way to zero.

When I took the pigtail off, there was still a small amount of pressure in the boiler, and water was flowing freely out of the 90. by the time I was done cleaning it, the pressure had reached zero and the flow stopped.

Since adjusting the settings, I have not noticed the pressure getting nearly as high but I am away most of the day so I can't keep a close eye on it. I'll try making the adjustment shown in the video and see if that helps.

KarlW

I was having overpressure problems myself this past December, and it appeared my vaporstat went bad. Trying to save myself a few hundred dollarsin replacemen t costs, I set up a little test set and found that by adjusting the setscrew (covered by blue stuff in the video) on my pressurtrol I was able to get it to cut out at about 1.2psi and cut in at 0.2 psi.

This has been great, as the natural point of my boiler (all radiators fully open, air venting properly) is closer to 0.7psi.

archibald tuttle

i would throw that pressurtrol away and get a vapor stat. and supposedly, i heard from (damn can't remember who) that there is a thread on here about a wally who found vaporstats so finnicky that he controlled pressure by monitoring the height of water in the return using some spaced out electrical sensors in the drop. that is friggin brilliant if they operate continuously without a lot of maintenance. obviously you use a simpler safety shut off but for operating controls! anybody got a link to that?