Proper Pressure Settings for Residential Steam Boiler

Don1450

Can someone direct me as to the proper settings for a Honeywell Pressuretrol installed on a residential steam boiler. I have a Burnham Mega-steam boiler (MST-288) that was installed last year. I flushed it out 4-5 times this week, filled it with fresh water and Rector-seal 8-Way Boiler Treatment, and then skimmed it. It runs perfectly and heats without any issues and has since it was installed. I have new radiator vents on all my radiators and new main vents.

My problem is that I am getting no needle movement on my pressure gauge. It reads zero all the time. The gauge is a 0-5 psi and has been tested and works. I've thoroughly cleaned the pigtails for both the gauge and the Pressuretrol. I've confirmed that the small whole in the Pressuretrol entry port is clean and clear. The fact that the gauge reads zero seems to have no effect on performance but is still seems very strange. I originally set the P-Trol at 1 psi (Diff) and 1 psi (Main). I changes it tonight to read 1 psi (Diff) and 2 psi (Main) but still no reading on the gauge.

Pictures:

Jamie Hall

The pressuretrol serves to turn the boiler off it the pressure rises above the cutoff setting -- which in your case should be 1 on the diff and 1 on the main, or even better 0.7 on the main. Reset it to where it was!

What it doesn't do is raise the pressure in the boiler. The fact that your 0 to 5 psi gauge doesn't move, and the pressuretrol doesn't turn the boiler off, and the system heats well, simply indicates that your boiler is very well matched to your system.

So be happy, don't worry. But do reset the pressuretrol...

Fred

Set the Pressuretrol "Main" to "1" or 1.5 and the Differential to .5PSI. You want as little pressure in the system as is possible so the fact you don't see the gauge move, but you get steam to all of the radiators is a GREAT thing. The boiler must be properly sized and working well. The Pressuretrol should actually be a safety devise and should not have to control the pressure in a system that is properly sized. It looks beautifully installed too!

EBEBRATT-Ed

Sounds like you got a good installation and the boiler is doing what it should be doing!

Kahooli

Nice boiler you got there. And really nice piping

Don1450

Thanks guys. I'm not an expert on steam heat but I did specify certain piping for the installers such as the very high risers and header (much more than the recommended 24") and the addition of main vents, etc. All things I gleaned from this forum. I was starting to come to the conclusion that the boiler simply was not building any pressure. You've put me at ease that this is fine given that everything seems to be performing well. I will run down and return the Pressuretrol to the settings you suggest. But if the Pressuretrol is a safety device that doesn't regulate the pressure then why does the boiler cycle on and off? It doesn't do this rapidly. But it will run for 10-15 minutes when the thermostat calls for heat then stop for a few minutes, then start again. Is there some other device causing this?

One other question...in Dan Holohan's "Steam Heating Primer" he recommends replacing the Pressuretrol with a Vaporstat and seems to be indicating that the device be used as an on/off switch for the system. Can you explain his thinking on this and say whether you think that a Vaporstat is a good investment?

KC_Jones

It cycles on and off because of the goofy thing I circled in the picture. It turns the boiler off to let the water settle to verify the water level is indeed fine.

Makes zero sense to me and I'm glad I don't have one. Read up on the device, there have been a few people recently changing them out for safeguard that still functions as a LWCO without the annoying shutdowns.

Vaporstat is still just a safety device, just a much lower scale for greater accuracy in a lower range. Well I should use accuracy loosely, but they do have a much lower range. If you aren't cycling on pressure I wouldn't waste the money.

Don1450

Makes sense. Thanks. I'll check out the article.

ratio

It's nice to hear about a boiler that's working good for a change.

lchmb

I would recommend having the draft damper reinstalled to spec's..;) otherwise a beautiful install...

New England SteamWorks

From the install manual:



I also agree that the CycleGard is very annoying. SafeGard is the way to go.

EBEBRATT-Ed

No need to waste money on a vaporstat, as mentioned above if your heating well without building pressure that's the way it should be. The Cycleguard low water cutoff is an issue.

The draft regulator should not be mounted on a tee as others have noted

mikeg2015

You might get a 32oz or 0-12 oz pressure gauge just so you can see what pressure you are running at.

I agree that a vaporstat would be a waste at this point.

A perfect system only needs the pressure control as a high safety limit, not an operating control. If well balanced and boiler sized on the smaller end with well insulated mains and run outs, you might hardly even need traps.

Danny Scully

@Don1450, your pressuretrol is subtractive. So, the Diff is subtracted from the main to determine the cut in. I would set it to 2 and 2. On your particular model, these are the easiest numbers to read. This way, the system will run to 2 psi, then it will drop to 0 (2-2=0) before it comes back on.

Don1450

"I also agree that the CycleGard is very annoying. SafeGard is the way to go."

They're both made by the same company. What's the difference between these two devices?

Jamie Hall

The Cyclegard is meant for boilers which have, or may have, a foaming condition -- usually due to the water quality (this is particularly true of boilers for consumed process steam). It automatically shuts off the boiler from time to time to allow any foam to settle, and then checks to see where the water level really is.

If you don't have a foaming problem -- and you most likely don't -- then you don't need that feature and you can use the SafeGard.

Don1450

So the Safegard only shuts off if a low water condition occurs, where as the Cyclegard shuts of for low water, but also intermittantly just to make sure that foam can settle?

I fairly confident that I don't have foaming because I've skimmed thoroughly and treated my water.

Fred

The Cyclegard shuts down periodically because the foaming can present a false sense of water when it is in contact with the probe so they shut the boiler down, let any foaming settle and then determine if there is a low water condition. It's not needed on a residential boiler and a PITA.

Rindor

Why do i have to press reset button for heat all time. Thermostat is working fine. Any help is appreciated 

neilc

Rindor,
STOP pushing that button until you get it fixed
u should probably start your own thread,
hot water or steam?
gas or oil?
burner reset?
or somewhere else on the boiler or pipes?
picture of the button you're pushing,
and STOP pushing that button until you get it fixed.

Jamie Hall

That reset button is used to override a safety cutout of some kind. Can't tell which one, but @Rindor , it's a safety cutout. It's there for a reason. Pressing it once, just one, may be OK. After that, if it does it again, turn off the system with the emergency switch and find the problem and fix it.

SteamingatMohawk

I find it interesting that in the era where many boilers are oversized and some owners utilize additional home made controls to prevent short cycling that some of you comment that the Cyclegard is annoying or PITA. Short cycling modifications create some form of periodic shutdowns, so what's the difference other than that, on mine, it is every 10 minutes for 90 seconds. Presumably it works before the Ptrol would activate. Although, using a Cyclegard moves the tripping function from one safety device to another.

The Cyclegard inserts a periodic shutdown does essentially the same thing as some of the home made modifications and comes from a well known manufacturer of residential boiler equipment.

I have the oversize condition with the Cyclegard on my boiler and find it to be superior to some of the things I have read in other discussions. Additionally, it is difficult enough to find a competent boiler service tech without complicating the situation with home made modifications.

Lots of people move every year and what happens when the property changes owners? Is there any insurance risk if home made modifications are made to systems, particularly in rental properties, like mine?

It seems to me that the Cyclegard is an almost perfect solution, since it is commercially available from a reliable company, helps prevent short cycling and doesn't require any additional electrical or mechanical equipment to function.

I don't own stock in the company, just like the functionality.

Rindor

Thank you @jamie and @neilc for your kind word and help. I turn off. What do you think is problem? Any idea? I recently install one circulator for stream boiler. Pressuretrol settings is as i took picture below. Can you tell me whats ideal settings for the family home. Thank you @Jamie Hall @neilc

pecmsg

What reset are you pressing?

Rindor

Hi @pecmsg , I m pressing "Push for reset" in first picture. I turn the heat running. 

pecmsg

2#'s seems a little low with the other set at below 2#'s but I never trust the dials to be accurate.
What does the pressure gauge readjust before it trips?

Jamie Hall

The first thing I'd check is the settings on the pressuretrol in the second picture. They're not right. The main scale -- the one on the right -- is OK, but the differential scale -- the one on the left -- isn't. That scale should be set to 0.7 -- halfway between 0.5 and 1.0. There is a screw on top above that scale which you can turn to adjust the setting.

Try that. I suspect that what may have happened is that that control may have hung up.

The setting on the scale on the other pressuretrol isn't really quite right either; try raising that one to 2.5 instead of 2.

It is also quite possible that the pigtail -- the pipe connecting the pressuretrol to the boiler -- is plugged. If changing the settings as above doesn't make a difference, you should figure out how to take the pressuretrols off and make sure that their connections are clear. If you're not comfortable with that -- it involves disconnecting the wiring and taking them off and then putting it all back together exactly the same -- a good heating person should be able to do it for you.

Rindor

Thank you @Jamie Hall
I set as you recommended. Is this correct? Can you confirm pls

I send picture below. It trip at 15PSI @pecmsg

pecmsg

Iv get a funny feeling the pig tail is plugged.

pecmsg

Can we get a pic further away?
Pressure gauge, primary and safety controls in the same shot

Rindor

Is this correct @Jamie Hall Can you pls confirm before i turn on.

Rindor

Pigtail i clean a month ago. I set pressuretrol as recommended by @Jamie Hall
Differetial 0.7approx, main = 1psi

On reset button pressuretrol at little over 2 psi

Looking for for final confirmation. Thank you so much. I hope it will run whenever room temperature drops down from 72Ferenheit.

pecmsg

Pig tail cleaned how about the rest of the piping, especially where it goes into the boiler?

Jamie Hall

The settings look correct now. If that pressuretrol with the red button trips now, somehow the main pressuretrol (the one without the red button) isn't seeing the pressure properly.

Or, just possibly, isn't wired properly.

neilc

pecmsg said:

Pig tail cleaned how about the rest of the piping, especially where it goes into the boiler?

can we see a picture of where the bigger pigtail/Ptrol piping connects to the boiler? showing as much as you can , , ,

Rindor

Thank you so much for your help @Jamie Hall and @pecmsg. I greatly appreciate.  Belated Merry Christmas. 
Currently it is working with temperature but once it fall below the set room temperature, its not kicking heat automatically. 

Rindor

@neilc @pecmsg
Pigtail view . Heat is calling when room temperature drop but only have to press reset button on second pressuretrol.

pecmsg

Can’t tell without being there. All connections need to be checked!

neilc

the pressure still looks a little high on the gage,
it could be worth checking that pigtail again,

pull the Ptrol off and see if you can blow down thru the pigtail back to the boiler, it should be easy to do once you clear the water seal in the pigtail loop,
if things don't blow easy, you're gonna have to check that larger pipe where it connects to the boiler, or at that plug on the left.

While the Ptrol is off, check the little hole up inside there,
maybe someone was a little too generous with the pipe dope, probe carefully.
refill a little water into the loop before replacing the Ptrol.

after that, you could dial that manual reset(red button) Ptrol up to 5, anything past that and I would go back to looking at the automatic and determine why it isn't controlling, maybe it needs replacing