If pressure gauge is near 5psi, is pressuretrol broken?

gilead1234

Hello all, in my never-ending quest to silence my system, I took a closer look at the boiler today and saw that the pressure gauge hovered up to three... then four... then above.

But my subtractive pressure trial is set to one and a half on the main and one on the diff. Which if I understand correctly should mean once pressure hits two the boiler stops boiling and the pressure drops. 

Does this mean my pressuretrol is broken?

And could those high pressures be contributing to inefficiencies, sounds, or even be dangerous?

neilc

under the Ptrol is your pigtail, and maybe some more small piping,
and that gets clogged up, especially the steel ones, which I think I see,
the pigtail needs to be free breathing, including any extra pipe, all the way back into the boiler, so your Ptrol can see the boiler pressure inside the chest.
have you checked and cleaned the pigtail, etc ?

gilead1234

Thank you. I haven't checked or cleaned the pigtail, so I'll give that a shot. Hopefully there are good YouTube's to tell me how to take it apart and clean it.

If they are clean already when I take it off, could the problem be the pressuretrol itself?

 neilc said:

under the Ptrol is your pigtail, and maybe some more small piping, and that gets clogged up, especially the steel ones, which I think I see, the pigtail needs to be free breathing, including any extra pipe, all the way back into the boiler, so your Ptrol can see the boiler pressure inside the chest. have you checked and cleaned the pigtail, etc ?

EBEBRATT-Ed

@gilead1234

Checking the pigtail and the connection into the boiler is the first thing to check as @neilc said. I would replace the pigtail with a brass one if yours is steel. Brass corrodes less and plugs up less often, In fact its better if all the fittings are brass

After that the pressure control scales are usually somewhat inaccurate. Your pressure gauge could be bad as well

neilc

does the pressure gage return to zero when the boiler has been off a while?

gilead1234

The gauge does return to zero, yes. I just took off the pigtail, gave it a good rinse and blew through it. Seemed relatively clean. Some soot but nothing notable. 

neilc said:

does the pressure gage return to zero when the boiler has been off a while?

neilc

what about the nipple and 90 between the pigtail and the boiler?
blow the whole way in ?

gilead1234

Went back in to check. There was a slight... I guess you could call it resistance, not much, more like some slight gargling when I blew. And a good blow did clear that out, so now it's perfectly clear. I'll take another look at the pressure gauge tomorrow morning when the boiler will be running for a while. (I'll get in trouble if I sweat everyone out of the house now.)

Many thanks for staying with me as I try to rule things out!

neilc said:

what about the nipple and 90 between the pigtail and the boiler? blow the whole way in ?

gilead1234

Okay @neilc @EBEBRATT-Ed, after cleaning out the pigtail and adjacent parts, and after adjusting the "main" setting up and back down (why not), I'm seeing now that it's cutting out when the gauge says just about 5, and cutting in when the gauge looks close enough to the expected .5. 

I understand the gauges, and even the pressuretrol, aren't precision instruments, but on the other hand the only info I have is telling me the pressure is many times more than we want it to be. And I might be able to swallow the wasted gas bills if it weren't 2 am now, and the reason I'm in the basement is because I was awakened by noise from my radiator!

Thanks again for any insight and thoughts about next steps. 

neilc

change the Ptrol,
well,
wait a minute,
does the Ptrol have a mercury bulb switch inside, or a micro switch?
care to post a better picture showing the whole Ptrol,
if it's mercury, then the Ptrol needs to be level and plumb,
there would even be a small pendulum in the back of the case for conveniences.

SteamingatMohawk

Picture including the pigtail.

gilead1234

@neilc I think it's mercury free. The Honeywell L404f. 


@SteamingatMohawk

neilc

yeah, that's a switch, not mercury,
and that nipple and 90 are clear all the way into the boiler?

I beat dead horses

gilead1234

When I blew through it, seemed clear(er) than a whistle.

neilc

I see what you've done there,

change the Ptrol,
or go to a 4psi vaporstat for more denaro

Charlie from wmass

I would assume that the gauge is partially clogged or malfunctioning. Remove the gauge and check piping near it.

neilc

but the gage returns to zero,

one more idea, wiring,
pull one wire off the Ptrol,
and set the heat all the way up to call the boiler on,
does the boiler fire ?
it should not,
if it does you have a wiring / safety issue there,

Charlie from wmass

Gauges for steam boilers frequently have an internal siphon which has an incredibly small volume and if the gauge is blocked a small change in temperature causes a large change in pressure.