pressuretrol psi gauge relationship?

notch

Hi all. I am very new to residential steam heat. I moved into a house in October and due to many projects that needed to be done I only started looking at my burnham enterprise gas boiler and researching steam heat this past few days. So I am as novice as they come.

My first question pertains to the relationship between my pressuretrol and my psi gauge during cycles. On the pressuretrol the main is set for 1 psi and the diff is set for 1.5 psi. After observing it through a few cycles I noticed the boiler cuts out when the gauge reaches 7 psi. The psi shortly raises to about 7.75 psi then cuts on when it drops back to 7 psi (approximately 5 min). It then shortly falls to 6.5 psi then starts raising again where it cuts out at 7psi again (approximately 6 min), Where the the cycle starts over.

I would have assumed with those pressuretrol settings that the cut in would be around 1 and the cut out 2.5. Is my pressuretrol/psi gauge mis calibrated/ broken? Also is that cycle time normal or would that be considered a short cycle? Thanks in advance for any ideas.

nicholas bonham-carter

Short bursts of very high pressure

Is your pressuretrol on the same tee as the gauge? If so that would rule out the possibility of a plugged pigtail. I think the linkage on the pressuretrol has become disconnected, and is letting the pressure run up.

There should be some threads on here dealing with pressuretrol repair, if you search.

If your venting is adequate, you should be able to get steam to all the rads with a few ounces of pressure. You may still cut out several times on pressure if the boiler is oversized.--NBC

Fred

Pressuretrol Settings

First, your pressuretrol should be set at 1 psi (white dial on the inside) and the differential should be down to .05 psi. Either your Pressuretrol isn't working or is way out of calibration. I suspect the syphon tube (pigtail the pressuretrol is mounted on may be plugged up with gunk. Turn the boiler off, take the Pressuretrol off and take the pigtail off and clean it. Make sure you can easily blow through it. Also check the Pressuretrol mounting and make sure the small hole in the center of it is clean.

Put it all back together and see if it stays within the 1.5 to 2 psi range. If it goes over the 2psi, follow this procedure to recalibrate the Presssuretrol:  

Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a tiny fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with) . You may need to play with it to get it exactly where you want cut out to be.

If it can not be re-calibrated, it is probably defective and needs to be replaced but I gut tells me the pigtail is probably plugged up.

notch

Thanks

Thannk you both so mutch for your quick and detailed reply. Living in New York we are dealing with one last cold spell after which I am going to try to clean and reconnect the pressuretrol. I will update the results after this. Thanks again

Fred

Don't Wait

I would not wait for the weather to break! That Pressuretrol is the only safety device you have on that boiler as it relates to keeping the steam pressure in a manageable (and safe) range. Without it functioning properly, your boiler becomes a dangerous appliance. At a minimum, running at the pressures you indicate, you can easily ruin all of your radiator and Main vents (they have an operating range of up to 3psi) and those aren't cheap. Worse yet, if it gets cold enough outside and the boiler runs long enough, it could get your pressure up to 15PSI at which point, the pressure Relief Valve on your boiler will blow and that is HOT, HOT Steam and water. It only takes 30 minutes to take the pressuretrol off and clean the pigtail. Well worth shutting the boiler down for those few minutes.

notch

Will check it asap

Unfortunetely this has been running like this since I moved in. In the past I have heard what I think is the pressure relief valve (doubles as main vent?) go off while I was working in the basement. I paid little attention to it thinking it was normal operation. So I assume all the vents are shot. I did not realize it was such a safety issue. I will take care of this immediately when I get home. Thanks.

Fred

No, Main Vents and Pressure Releif valves are different

No, your main vents should be located somewhere towards the end of your main piping or return lines, mounted up close to the floor joists. The pressure relief valve for your boiler is a brass valve, mounted on your boiler and located somewhere around the top of your boiler. It has what looks like a flip lever on top of it to allow you to test it periodically and should have a pipe that drops to the floor with that end being open (if you have a gas water heater, it will have a very similar one on it).

Be careful and make sure the boiler is powered off and that the boiler has had enough time to cool a bit.

notch

Still not working

I cleaned the mud out of the pigtail. Unfortunetely the boiler ran at the same pressure. I took the pressuretrol off examined the orifice wich was fine. I could not find the screw to calibrate it. It is a Honeywell L404F 1367. I then set the pressuretrol close to zero and I am getting the same result, which makes me wonder if calibrating will do anything. I think I may just going to have to order one. I checked my local plumbing supply store and they don't carry it. I hate to leave this thing like this for the few days it takes me to get it.

notch

I should have opened my eyes

Thanks. Don't know how I missed that pressure relief valve even after going over the boiler a number of times to figure it out.

Fred

Sounds like Pressuretrol

It does sound like the diaphragm in the Presuretrol may have failed. The Honeywell Pressuretrols are typically readily available locally. Call a Heating contractor that services Steam boilers or a Heating supply house. They will have one. Running at that pressure is not something you want to do.

notch

New pressuretrol. Same result.

Replaced the pressuretrol and still got the same result. I am now wondering if the pressure gauge is the problem. When it was reading 6 lbs I manually opened the relief valve and nothing came out. I was always under the idea that those pressure gauges didn't lose calibration. When they broke, they stayed at 0psi.

BobC

Bad gauge

Pressure gauges fail more often than pressuretrols do, replace it.



Bob

notch

Pressure relief valve

I've been observing the pressure relief valve during cycles and noticed a small bit of steam comming out of the bottom of that pipe after the boiler has been firingl404f1367. Nothing audible like when I manually open it. Is this normal steam passing the valve? Or is this an indication that my pressure is approaching 15psi.

notch

New gauge comming.

I hope that's all it is. Going to replace it with a tee with 2 gauges (0-3 & 0-30) like I've seen on this forum.

Fred

Not Normal

It is not normal for any steam or water to escape from the pressure relief valve. Given what you already know about your steam pressure, I'd be very cautious about running the boiler very much until you get that Pressuretrol replaced and it is probably a good idea to replace the Pressure relief valve as well. You may only have some dirt/rust keeping that valve from completely closing but better safe than sorry, especially since they are cheap. BobC suggested replacing the pressure gauge also. It probably is not a bad idea, just to know for sure that the gauge is good but there is enough evidence, with this relief valve issue to be very suspect that the Pressuretrol is not doing its job. 

Put the new gauges on the same pigtail as your Pressuretrol. They need to be protected from the steam as well and you will be able to see exactly what the Pressuretrol should be seeing.

BobC

Bad valve seat

Pressure relief valves are known to leak a bit after being actuated so that may have to be replaced.



Bob

notch

Tomorrow's work

Installed a new pressuretrol earlier today so I am confident it's the pressure gauge malfunctioning. I like the idea of setting up the new gauge on a tee above the pigtail just to make sure I know what's going on with the pressure trol. I will also be replacing that relief valve. Thanks again to everyone with all your help.

notch

Redemption!!!

I installed the tee over the pigtail with a new 0-30 psi gauge (could not get my hands on a 0-3 today). I left the old gauge on to see how it compared to the new one. It rose about 5 lb for every 1 lb on the new gauge. Before you say it I triple checked that the old gauge was not kpsia. So the boiler may have been working at a normal pressure all along. All and all I am almost happy that I did not check the gauge first as this was great tutorial for me to start to understand my boiler. I want to thank NBC, Bob C and Fred so much. With out your tips I would still have my head up my **** as when it comes to heating my home. I look forward to using this sight as a reference in the future. And maybe one day being able to contribute. Thanks again.

Pat

Fred

Great!

That is great news! I look forward to seeing you post on this site soon! Don't forget to clean that pigtail out periodically

curiousburke

this is my exact situation!

I also bought in October and have burnham that reads high pressure, but my pressuretrol doesn't shut it down:



1) pressure gauge goes to 13psi always and higher at least once

2) pressuretrol did nothing

3) pigtail was clogged

4) replaced pigtail, pressuretrol and put in a T to a 0-15psi gauge

5) new gauge always reads 0psi

6) new pressuretrol does nothing, although it does work manually



My plumber took a quick look while here for something else, and thinks the old gauge is busted and the pressure is too low to read for the new gauge.



Another local plumber, who has a lot of steam experience suggested releasing the relief valve if there was high pressure I would know it. I did this and the result was a very low flow of steam.



So, all evidence points to the pressure being low and a busted gauge, but should the new gauge really just read 0psi? The pressuretrol is mounted on the LWCO. Could the pressure in the boiler be different from what the pressuretrol sees? Water did pour out when the pigtail was removed and the hole cleaned because it is below the water level in the boiler.



Thanks for any help,

Mark

BobC

It depends

If your boiler is well matched to the radiator load then the system can run happily on ounces of pressure. If the boiler is larger than the radiator load it will build pressure and that is why they put a pressuretrol on the system.



Think about adding an auxiliary 0-3PGI gauge so you can see where the system is operating at, those 0-30 gauges are useless at the low end of the scale.



Bob

curiousburke

0-3psi gauge

yeah, I have wanted to get a 0-3psi gauge, but have put it off as a luxury expense ... maybe it's not. Are there any good inexpensive low pressure gauges?



Do you think there is any way the new gauge and pressuretrol are not seeing the internal boiler pressure?

curiousburke

pressuretrol setting

I should have mentioned, on the advice of plumber #2, I set my pressuretrol to it's loosest setting by unscrewing the set screw altogether, so the spring just hangs free. Does anyone have an opinion on doing this?

Fred

Not right

You need to reattach the loose screw on the Pressuretrol and set it at the lowest setting (.05psi) Set the main to 1psi. (giving you an upper limit of 1.5psi if your Pressuretol is additive)They are not designed to run without some tension on the arm the spring is attached to. It is not unusual for the 0-15 and 0-30 psi gauges to read 0 pressure. They are not sensitive enough to read low ounces. Put that 0-3psi gauge on there along with the 0-30 (required by code). With the 0-3psi gauge you will see a couple to a few oz. of pressure on the gauge. Also, the pressuretrol will only turn the burner off if/when you reach/exceed the upper limit which shouldn't be often, maybe when you are raising the house temp a few degrees or possibly when the weather is really cold outside and the boiler runs for an extended period. With that loose screw, the Pressuretrol probably will not let the boiler burner kick back on like it should after the upper limit was reached.

GeoffG

Wika 0-3 psi gauge

Wika is considered a good option. I just installed mine this weekend and began tweaking the Pressuretrol.

curiousburke

thanks

I missed this post earlier. I checked them out. I see they are a little cheaper than Valworx; is it the same quality?

curiousburke

okay, I'll fix it

It seems like it's basically the same thing as the 0.5 setting, but if it's better to have it attached, I will hook it up.

Fred

Wika is a brand name/Division of Valworx

When you order from Valworx, you will get the Wika gauge (same gauge as GeoffG suggested in earlier post). I'm not sure if Wika is a division of Valworx or if it is just the brand name that Valworx uses for its valves and gauges. 

GeoffG

Good quality

It's a Swiss movement, so I have to believe the quality is good. The unit feels very solid and it's good to see it actual work compared to the ridiculous 30 psig.

curiousburke

oh

Okay, so its the same. Great thanks both of you for the suggestion

curiousburke

Wika gauge just flutters

I installed a 0-3psi gauge and cranked the heat, but the gauge only flutters near zero. After some time the pressure got to 0.1psi. Do i need to zero the Wika gauge somehow? The heat works, and I know the gauge works because it read 0.5psi after screwing it on due to the compression of the trapped air. Opened the stopcock to relieve it.



Whatever the pressure is in the boiler, it doesn't appear to be the same at the pressuretrol, or can the system really operate at near zero psi?



I don't know if this is diagnostic, but I notice the gauge pinned to zer as soon as I shut down the boiler. I think I must be doing skmethiing wrong and I'm a little concerned about not knowing the true pressure. What could be wrong?

BobC

It takes almost zero pressure

to run a steam system if the boiler is closely matched to the radiation. On a real cold morning you might see more pressure especially if you were coming back from a night setback.



Bob

curiousburke

can they really run on 1 oz?

My house heating fine while the gauge wasn't even above the zero tic. Is there any way to independently confirm the internal pressure?



I don't mean to keep pushing on this, I just don't want my boiler exploding because the pressure gauge was hooked up wrong

Fred

Sounds OK

It sounds OK. If the gauge is not set at 0 when the boiler is not running, you can adjust the needle using the little adjusting screw under the plastic cover on the front dial. Your instructions will show you how but the pressure gauge is not going to show a lot of pressure unless the boiler runs for an extended period of time. That low pressure is exactly what you want.

If you want to sit with the boiler for a half hour, you can turn your thermostat up about six degrees and then sit by the boiler and watch the pressure build a few ounces on that gauge but I can assure you it is fine. Once you are comfortable that it is working, turn your thermostat back down to where you want it.

BobC

It should be fine

the 0.1PSI is about 1.6oz of pressure and that is enough to fill the pipes with steam. The vacuum you see when the boiler shuts down is normal and shouldn't bother the gauge.



When the boiler is cold you can manually adjust the gauge zero.



Bob

curiousburke

okay, thanks all

It did climb to 0.1 in about 10 minutes, so I guess in 30 minutes it would build a little pressure. Maybe I should try that clear hose trick just to double cinfirm

Fred

Don't try any clear hose trick

Don't try any clear hose trick. You are dealing with Hot, Hot Steam here and everything sounds like it is running fine. Don't obsess about this until you get hurt. It's working

curiousburke

oh, I didn't realize that it was not

a recommended technique.