New low pressure gauge reading zero

wilder0m

I added a 1-5 PSI gauge to my boiler to get a better read of pressure than the 1-30 gauge on there. The gauge read zero the entire time the boiler ran, for 20 minutes until the thermostat kicked it off. 

Did I install it wrong? Buy the wrong gauge? Or is the pressure really zero?

guzzinerd

If you're getting heat to all the rads, I think that's a good thing.

wilder0m

guzzinerd said:

If you're getting heat to all the rads, I think that's a good thing.

Well, all but two of them are getting heat (see my other recent thread for that ongoing story; I don’t think pressure is the problem there, because other radiators further away are getting heat). 

But is a flat zero reading really a good thing? I thought at least a few ounces of pressure was normal. 

ethicalpaul

Mine fully heats my radiators with 1/27th of a PSI

After some fill with steam it will start to rise a bit.

try recovering from a setback to see if it starts to register

Pumpguy

You might try adding a vacuum gauge to your gauge piping.

Substitute a Tee for the elbow, with the run of the tee horizontal and the branch opening up. Put your 0-5 psi pressure gauge in the branch of this tee. Add a 4" +- nipple to the run of the tee, add your elbow, and add the vacuum gauge there.

The vacuum gauge will tell you if the pressure is going below atmospheric. Not a bad thing at all, and now you'll know where your pressure actually is.

wilder0m

ethicalpaul said:

Mine fully heats my radiators with 1/27th of a PSI

After some fill with steam it will start to rise a bit.

try recovering from a setback to see if it starts to register

Thanks, I’ll try that in the morning when I turn up the thermostat for the day. 

wilder0m

Pumpguy said:

You might try adding a vacuum gauge to your gauge piping. Substitute a Tee for the elbow, with the run of the tee horizontal and the branch opening up. Put your 0-5 psi pressure gauge in the branch of this tee. Add a 4" +- nipple to the run of the tee, add your elbow, and add the vacuum gauge there. The vacuum gauge will tell you if the pressure is going below atmospheric. Not a bad thing at all, and now you'll know where your pressure actually is.

Interesting, I didn’t know that was possible. What would below-atmospheric pressure be a sign of? 

ethicalpaul

wilder0m said:

Interesting, I didn’t know that was possible. What would below-atmospheric pressure be a sign of? 

It's a sign that your call for heat ended, the burner shut down, and the steam in the system condensed to water.

delcrossv

You need one of these. Ounces, not pounds.

https://supplyhouse.com/Winters-Instruments-PLP301-2-1-2-PLP-Steel-Low-Pressure-Gauge-1-4-Bottom-NPT-w-Brass-Internals-0-32WC

ethicalpaul

"need" is a strong word

Here's a less expensive one that measures inches of water (there are 28 inches of water column in a single PSI)

https://www.amazon.com/SENCTRL-Inches-Pressure-Capsule-Adjustment/dp/B0C6KJ8865

delcrossv

ethicalpaul said:

"need" is a strong word

Here's a less expensive one that measures inches of water (there are 28 inches of water column in a single PSI)

https://www.amazon.com/SENCTRL-Inches-Pressure-Capsule-Adjustment/dp/B0C6KJ8865

"Need" was chosen with care. Winters is probably the cheapest gauge that has reasonable accuracy. Not like I suggested a Magnahelic.

KC_Jones

delcrossv said:

"need" is a strong word Here's a less expensive one that measures inches of water (there are 28 inches of water column in a single PSI) https://www.amazon.com/SENCTRL-Inches-Pressure-Capsule-Adjustment/dp/B0C6KJ8865

"Need" was chosen with care. Winters is probably the cheapest gauge that has reasonable accuracy. Not like I suggested a Magnahelic.

Nothing wrong with a Magnehelic. This one showed up at my house from some nice guy named Paul. Just had to take him out crabbing on my boat. Works like a charm.

ethicalpaul

https://www.ebay.com/itm/276312317757

wilder0m

@delcrossv @ethicalpaul ok, I’ll buy one of them if my 0-5 stays at zero. But is it odd that the gauge needle isn’t even budging off the zero stop? Does anything look wrong with the installation?

delcrossv

wilder0m said:

@delcrossv @ethicalpaul ok, I’ll buy one of them if my 0-5 stays at zero. But is it odd that the gauge needle isn’t even budging off the zero stop? Does anything look wrong with the installation?

Nope, You're just running below the sensitivity of the gauge.

Here's a much larger system I maintain .Note the gauge pressure (in ounces)

109A_5

Hello @wilder0m,
As long as your pigtail and/or the boiler tapping is not plugged up. Like others my boiler does not go over 1.25 Inches of Water column.

1.0 Inch of Water column = 0.578 Ounces = 0.0366 PSI = 0.249 kPa.
Think about where that would be on that gauge.



Oh by the way the weight of the water in the pigtail has a slight bias on the reading too. I have my gauge connected to the top of the boiler (no pigtail) through a long small tube.

wilder0m

@109A_5 thanks, the pigtail and 1/4” fittings are new, so they aren’t clogged. But I didn’t check the  3/4” pipe coming directly from the boiler. I can’t tell if this was even removable or a permanent piece of the boiler. Does anyone know? 

RTW

Heres a LINK to Heating Help article by Dan Holohan that may answer your concerns on the gauge issue

https://heatinghelp.com/systems-help-center/why-steam-boilers-short-cycle/

Regards,
Bob

ChrisJ

I need to join in.

https://youtu.be/zyxLbXq61-U?si=_9yOnsMGcNq059kA

dabrakeman

@wilder0m My 0-3psi gage also does not budge on normal cycles. Got it mainly to verify where cutout with my pressuretrol would really happen if the situation arose where it needed to. 30psi gages are useless even at 1-2psi.

wilder0m

dabrakeman said:

@wilder0m My 0-3psi gage also does not budge on normal cycles. Got it mainly to verify where cutout with my pressuretrol would really happen if the situation arose where it needed to. 30psi gages are useless even at 1-2psi.

Thanks. I thought the 1-5 PSI gauge would be sensitive enough but apparently not. I am going to get one of gauges recommended above that max out around 1 PSI. 

ethicalpaul

I will add that even at my pretty low pressures, I can typically see my 0-3 or 0-5psi (I can't remember which it is) gauge moving a little. That's why I suggested trying a longer call for heat to see if you could see it budge.

If it doesn't even in a longer call for heat, I would see if you have a blockage. You can remove your gauge and blow into the pipe to see if air flows into your boiler.

Pumpguy

wilder0m said:

Pumpguy said:

You might try adding a vacuum gauge to your gauge piping.

Substitute a Tee for the elbow, with the run of the tee horizontal and the branch opening up. Put your 0-5 psi pressure gauge in the branch of this tee. Add a 4" +- nipple to the run of the tee, add your elbow, and add the vacuum gauge there.

The vacuum gauge will tell you if the pressure is going below atmospheric. Not a bad thing at all, and now you'll know where your pressure actually is.

Interesting, I didn’t know that was possible. What would below-atmospheric pressure be a sign of? 

When the system is at vacuum, you have lower temperature steam which means you still have steam in the radiators giving off heat.

This also means you have a more rapid warm-up at the next cycle because the steam doesn't have to push as much air out first.

ethicalpaul

This also means you have a more rapid warm-up at the next cycle because the steam doesn't have to push as much air out first.

Well let's be realistic. This system isn't going to have a vacuum for very long, certainly not at the next call for heat.

guzzinerd

ChrisJ said:

I need to join in. https://youtu.be/zyxLbXq61-U?si=_9yOnsMGcNq059kA

Don't mean to hijack, but since you posted this can you tell me how you connected it?  I have this one but don't know which port to use, there's one on the side as well.  Once connected do I block the others?

Thank you!

ethicalpaul

There are two ports for the low pressure side and two ports for the higher pressure side. One each on the back and one each on the side. In our use case, you will pipe to one of the high pressure ones, then plug the other high pressure one, then leave the low pressure ports open.

In your photo above, the high pressure rear port is seen next to the orange rubber pressure relief plug

guzzinerd

Thanks! @ ethicalpaul 

ann1more

Ethanol Paul "need" isn't a strong word. It was a suggestion to find what the op was looking for, and the economical version at that, of ounces vs pounds gauge. No need to dissect words and add a emoticon??

WMno57

ann1more said:

Ethanol Paul

I think Paul is more of an "Electrify" than an "Ethanol".
Hmmmmm, I wonder if I could run my water heater on E85?

wilder0m

Update: the reason the gauge wasn't working was that the pipe between the boiler and the pigtail was incredibly clogged - see first photo. I cleared it, but I'm concerned that if the clog was that bad, my boiler must be really gunked up. I am going to call a pro for some boiler maintenance, but any recommendations from this crowd on what kind of cleaning/treatment/skimming/(fill in the blank) to request?



I put on a 0-18 oz gauge (thanks @delcrossv and @ethicalpaul for the gauge recommendations). It's now reading between 1 and 1.5 oz when the boiler is operating, which seems okay (not shown in photo, boiler is off here).

However, my next goal is to reduce the water hammer in the system, and thinking a first step could be getting the boiler de-gunked. Recommendations appreciated.

ethicalpaul

It doesn't necessarily mean the whole boiler is gunked up. Gunk just tends to form there (that's why checking/clearing the pigtail is a part of any good maintenance service call).

The boiling action of the water tends to keep the lower parts of the boiler relatively gunk-free. What happens if you drain about a gallon of water out of your lowest drain? What color is the water? Does it start out "muddy" then clear up?

wilder0m

ethicalpaul said:

It doesn't necessarily mean the whole boiler is gunked up. Gunk just tends to form there (that's why checking/clearing the pigtail is a part of any good maintenance service call).

The boiling action of the water tends to keep the lower parts of the boiler relatively gunk-free. What happens if you drain about a gallon of water out of your lowest drain? What color is the water? Does it start out "muddy" then clear up?

Thanks for the reply. Yes when I had a pro here about a month ago he drained the boiler and it was first muddy but eventually running clear-ish. That was all he did though, no other maintenance, as it was just a diagnostic call. But my other evidence that it's very dirty is that I replaced the sight-glass and it was already pretty gunked up again within a couple days.

ethicalpaul

That might be more a sign that the boiler needs to be skimmed. Has it ever been? Does it have a skim port currently piped?

Also note that draining and refilling the boiler can result in more "mud" being formed by the oxygen in the fresh water causing additional corrosion.

wilder0m

ethicalpaul said:

That might be more a sign that the boiler needs to be skimmed. Has it ever been? Does it have a skim port currently piped?

Also note that draining and refilling the boiler can result in more "mud" being formed by the oxygen in the fresh water causing additional corrosion.

I don't know if the boiler has been skimmed. The skim port just has a cap on it. See photo. What would the piping would look like if it was set up for skimming?

ethicalpaul

It is set up. You could remove that cap and you'd be all set for skimming (which is nothing more than just opening slightly the makeup water valve to let water slowly come into the boiler, letting the water level rise to the level of that skim port, and letting the water slowly run out of that skim port into a bucket (where the water flow is about the size of a pencil) for an hour or two.

ethicalpaul

Also your pressure relief valve (PRV) is installed incorrectly. It must be oriented so the test lever is up.

wilder0m

ethicalpaul said:

It is set up. You could remove that cap and you'd be all set for skimming (which is nothing more than just opening slightly the makeup water valve to let water slowly come into the boiler, letting the water level rise to the level of that skim port, and letting the water slowly run out of that skim port into a bucket (where the water flow is about the size of a pencil) for an hour or two.

Incredibly helpful, thank you. One of the pros I had in last month was giving me a four figure quote for repiping necessary to do skimming, but they could not explain to me what needed to be repiped. I suspected that was BS but it's a relief to have some confirmation.

So to clarify, what are the signs that skimming is needed here as opposed to just draining? Is it the fact that the gunky ports on the boiler (sight glass and Pressuretrol port) are at or above the water level?

ethicalpaul

Yes, to me that is a tell. Also if you see anything floating on the water in the gauge glass.

But the best reason to do it is because it is easy, doesn't hurt anything, and lets you see for sure what is floating on your water (you will see it flow out if you keep things nice and slow).

You don't want to boil the water when you skim....you can do it a few hours after the last call for heat to give the oils a chance to collect at the surface, then start your skim.

The four-figure guy is either a scammer or completely ignorant.

wilder0m

ethicalpaul said:

The four-figure guy is either a scammer or completely ignorant.

I think maybe both.

reggi

109A_5 said:

Hello @wilder0m, As long as your pigtail and/or the boiler tapping is not plugged up. Like others my boiler does not go over 1.25 Inches of Water column. 1.0 Inch of Water column = 0.578 Ounces = 0.0366 PSI = 0.249 kPa. Think about where that would be on that gauge. Oh by the way the weight of the water in the pigtail has a slight bias on the reading too. I have my gauge connected to the top of the boiler (no pigtail) through a long small tube.

wilder0m said:

Update: the reason the gauge wasn't working was that the pipe between the boiler and the pigtail was incredibly clogged - see first photo. I cleared it, but I'm concerned that if the clog was that bad, my boiler must be really gunked up. I am going to call a pro for some boiler maintenance, but any recommendations from this crowd on what kind of cleaning/treatment/skimming/(fill in the blank) to request? I put on a 0-18 oz gauge (thanks @delcrossv and @ethicalpaul for the gauge recommendations). It's now reading between 1 and 1.5 oz when the boiler is operating, which seems okay (not shown in photo, boiler is off here). However, my next goal is to reduce the water hammer in the system, and thinking a first step could be getting the boiler de-gunked. Recommendations appreciated.

As Suggested back here on the 6th by @109A_5

EBEBRATT-Ed

The weight of the water in the pigtail has no effect on the gauge reading if the gauge is above the boiler tapping