Faulty pressurestrol or gauge

Ying

So my pressuretrol is set at 1.8 main and 1 diff (subtract).

Notice that the 0-30 gauge, will go all the way up to 9 or 10, after the initial start up, then it wil take about 5-6 minutes for the gauge to go back down to 3-3.5. At that time, guess the psi is low enough for the pressuretrol, boiler will start up again and in about 6-7 minutes the gauge will read 9 or 10 again. Boiler will continue to turn on and off around those times and gauge reading till thermostat stop calling for heat.

Want to make sure which equipment is wrong before I start making replacements.

Essentially what I'm trying to find out is does psi build up and drop that fast. 6 psi in 6 minutes averages out to 1 psi per minute.

By the way, boiler is a burnham independence gas boiler. SIN6LNC-LE2

Gsmith

Very likely that the pigtail (curled pipe) under the pressuretrol is clogged. Try removing the pressuretrol and cleaning it, after turning off the boiler or turning the thermostat WAY down so the boiler doesn't come on.

nicholas bonham-carter

When you reassemble the pigtail after cleaning, put some unions on the pressuretrol, so you won’t have to unwire it.
If the pigtail is steel, then replace it with a copper/brass one for more resistance against clogging.
When the burner goes out, the stem immediately begins to collapse, leaving a vacuum in the system, causing air to rush into the system. Unless you have a 2-pipe vacuum system, a faster drop in pressure would indicate that your main (not radiator) vents are adequate, so check those for operation/capacity.—NBC

Ying

Thanks for the response. The pigtail will be clean even if I don't change the pressuretrol.
Just to clarify, so pressure do build up that fast in the boiler? Assuming that cleaning the pigtail gets the pressuretrol working correctly and there is nothing wrong with the gauge, Won't my boiler be coming on and off every minute or two?
That cycle seems very short to me to be working properly.

Steamer1928

nicholas bonham-carter said:

When you reassemble the pigtail after cleaning, put some unions on the pressuretrol, so you won’t have to unwire it.
If the pigtail is steel, then replace it with a copper/brass one for more resistance against clogging.
When the burner goes out, the stem immediately begins to collapse, leaving a vacuum in the system, causing air to rush into the system. Unless you have a 2-pipe vacuum system, a faster drop in pressure would indicate that your main (not radiator) vents are adequate, so check those for operation/capacity.—NBC

NBC, I would benefit from such a union also. Could you point me to one that would work? I have the standard size pressuretrol/pigtail setup.

ethicalpaul

Here's one: https://www.supplyhouse.com/Bluefin-BRU025-1-4-FIP-Brass-Union-Lead-Free

Jamie Hall

While you are cleaning the pressuretrol and all -- do yourself a favour and get a T and a few nipples and elbows and a 0 to 3 psi gauge, and mount them on the same pigtail as the pressuretrol. Takes a bot 10 minutes... (oh -- and some tape or dope) and then you will really know what your pressures are. That 0 to 30 gauge has to stay, for insurance, but they are rarely all that accurate.

Ying

> @nicholas bonham-carter said:
> When you reassemble the pigtail after cleaning, put some unions on the pressuretrol, so you won’t have to unwire it.
> If the pigtail is steel, then replace it with a copper/brass one for more resistance against clogging.
> When the burner goes out, the stem immediately begins to collapse, leaving a vacuum in the system, causing air to rush into the system. Unless you have a 2-pipe vacuum system, a faster drop in pressure would indicate that your main (not radiator) vents are adequate, so check those for operation/capacity.—NBC

So was able to change the pigtail today. Old one was indeed clogged and unable to be clean. Store I was at did not have a low psi gauge, so that migh be a job for another day. As for the union, did not notice that you need a nipple to connect the pressuretrol to the union, so that too another time.

Results ended up being about the same. Gauge will still go up to 10 before boiler goes off and then to about 3 before it goes back on with maybe 30 more seconds each way.

Thoughts guys? Should I replace the pressuretrol?

@nicholas bonham-carter, to clarify, when you said adequate, you mean that it is working fine right? Just want to make sure it was not a typo. Also, I can't seem to locate the main vent valve. Is it possible for a system be be without one?

Ying

> @nicholas bonham-carter said:
> When you reassemble the pigtail after cleaning, put some unions on the pressuretrol, so you won’t have to unwire it.
> If the pigtail is steel, then replace it with a copper/brass one for more resistance against clogging.
> When the burner goes out, the stem immediately begins to collapse, leaving a vacuum in the system, causing air to rush into the system. Unless you have a 2-pipe vacuum system, a faster drop in pressure would indicate that your main (not radiator) vents are adequate, so check those for operation/capacity.—NBC

Replaced the pigtail today. Old one was indeed clogged. Store I went to did not have a low psi gauge and didn't notice that will need a nipple to connect the pressuretrol to the union I got, so those will be project for another time.

Results ended up being about the same, even with a working pigtail. Gauge will still clime to 10 before boiler goes out and will go back on when gauge drops to about 3. Only now it takes about 30 second to a minute more for each part of that cycle.

Thoughts guys? Should I replace the pressuretrol?

@nicholas bonham-carter, to clarify, when you said adequate main vent, you mean that it is working correctly right? Just want to make sure it was not a typo. As I can't seem to locate any vent valves in the basement. Is it possible for a system to be without one? Where are they typically located?

Thanks

Jamie Hall

It is possible for a system to be without a main vent -- and it will work remarkably poorly as a result. There may have been one, once, but it may have been removed -- or in some old coal one pipe systems, there may never have been one.

In any case, main vents are needed. In one pipe systems, they are located near the ends of the steam mains -- after the last radiator takeoff if possible, but otherwise as close as may be. They need to be high capacity -- a standard radiator vent simply won't do.

So wander around in the basement staring at steam mains and see if you can find any and, if so, figure out what they are (or post a photo).

neilc

on that pressure still climbing too high,
if the pigtail was so badly clogged, is it possible the port into the boiler is clogged over as well? did you check this? might be worth one more look.
And for that matter, check the little hole under the Ptrol also

Fred

Did you try to make any adjustments on that Pressuretrol, like stretch any of the springs or anything? How long has this problem been going on and what, if anything changed when it first began? Did anyone remove the four screws on the bottom of the Pressuretrol? There is a free floating "pellet" in there that will fall out if those screws are removed. That pellet is what trips the micro switch. Pressuretrols can be re-calibrated but we first need to understand that it will still function reliably before we advise how to re-calibrate it.

BobC

If you remove the pressuretrol and turn it upside down you can look into the brass coupler that threads onto the pigtail. That brass coupling has a tiny hole in it (1/32"), make sure it's clear becuse if it's clogged your pressuretrol won't work.

Bob

Ying

Thanks all for the input.

I clean the port of the pigtail too before installing the new one. It had a 1 inch nipple on it. Clean and blew compress air into it until steam came it. Boiler was running right before I turn it off to make the change.

As for that little hole on the pressuretrol, also clean it and blew compress air into it. It clicks rapidly when I did that, so I don't think it is clog.

Bought the place 3-4 years ago and having touch the system till recently. When I hire someone to fix a leaking radiator valve turn into replacing the whole radiator. That's when I decided to learn the system and found this site.

Only adjustment on the pressuretrol was turning it down from 3 main 1.5 diff (sub) down to 1.8 main and 1 diff after reading posts on this site.

As for the main vent, see below pictures of my mains, the expose parts anyways. Had the basement finish and the only expose parts are one room at the end of the house where the boiler is and one room all the way at the front of the house where all the meters are.

Picture 1-3 are pipes in the boiler room. Picture 3 shows the pipe going up to the radiator on the bedroom right above it and then into a finish basement ceiling. Picture is all the way at the front of the house where the wet return pipe starts as well. With 2 pipes going up to what I'm assuming is the room above it and the staircase hallway for the second floor.

Don't see any signs of a main vent. Are they located before the pipe to the first radiator or after the last radiator? Or can it be anywhere in between that might be sealed up when the contractor put the ceiling and walls up in the basement?

Also assuming there is a main vent in the sealed up areas, won't I be able to heard some hissing sound as the boiler goes on and off, as air travel in and out through the vent valve? So far the only hissing sound seems to be coming from the boiler room.

JUGHNE

How about a picture of the piping from the front of the meter, as if you were going to read it.
Then back up to show ceiling to floor of piping in meter room.

I don't see anything in the boiler room that would give hissing sound except could it be the gas fire itself you hear.
If you hear the hissing and then switch off the boiler, will it stop or continue?

Ying

Here are some more pictures of the piping in the meter room. As for the hissing sound in the boiler room, it continues for about 5 minutes after the boiler cuts off.

Quite sure that it comes from the main pipes. Not sure if is high pressure steam moving through or if there is a main vent behind the sealed up area thats releasing air/steam, that maybe is radiating back to the main in the boiler room.

JUGHNE

Is the steam pipe in the meter room the end of the steam piping?
Then the return drops down to the lower pipe wet return, does it run around the basement back to the boiler lower inlet?
Are there any more pipes dropping into the wet return on it's way back.

In the meter room do you know where the two vertical risers go that come off the top of the pipe?

Air venting should be on the steam main after the last radiator connection. It could be possible that the last riser had a vent above the ceiling and maybe has a plug installed there. The ceiling may have been added after the plug installation.

There should be no vents near the boiler unless there is a upper return pipe somewhere that drops into the lower wet return.
If you are hearing an air vent that is working, it should close when the steam gets to it.

Your boiler piping is quite wrong, but fixing the venting will give you good return on the investment.

Your steam main looks to run uphill from the boiler so any water in it would run back to the boiler....(counterflow piping).
And then in the meter room that pipe should drain back to the wet return (parallel flow piping).

Another good investment are 2 books available from Dan Holohan….."We Got Steam Heat" and also "The Lost Art of Steam Heating-Revisited"
These are good hands on books that everyone here probably has.

You can download the install book for your boiler, good info there concerning piping.

Ying

Yes the meter room is the far end of the piping. And yes it runs on one side of the housr all the way back to the boiler. Don't believe there are any more wet return drops between this one and the boiler.

As for the 2 raises, there are 2 floors above the meter room. Peeping through the gap. The further one makes a left turn, I believe to the radiator at the 1st floor right above the meter room, radiator is aboit there. The inner one makes a right turn, perhaps to by pass the window where the first floor radiator is and up through a wall to the 2 radiators on 2 separate rooms on the second floor.

As there are 90 degree elbows on those raises, can I safely assuming there are no main vent in between the basement ceiling and first floor flooring.

Will it be worth it if I cut the 90 degree elbow after the last raise and install a main vent there? And can the vent be at an angel as sapce are limited.

JUGHNE

What does the second gas meter do?

Approximately how long is your steam main from boiler to the drop at the meter? (it looks to be 2" pipe??)

IIWM, I would leave the last reducing 90 intact and work with the 2 45 elbows on the drop.
The vents work best on the top of horizontal steam line but some are installed on vertical drops and can work fairly well.

Air vents themselves need to be vertical to allow any condensate to drain back into the return. Adding fittings can achieve this.
Would be very helpful if there was a union below the existing 45 elbows....can't see in the picture.

Ying

2 family house, 2 meters for each unit. Main is about 52 feet.

Yeah was think last night that a union my be needed after to put the pipe back together. Current piping does not have one.

Also can't seem to find any store around me that stocks the low psi gauge to attached to the pigtail. Can someone post a link to one that I can buy online.

Thanks

ethicalpaul

I bought this one, it's been perfect. There are probably less $ ones out there. I looked on supplyhouse.com and couldn't find a 0-3psi but if they have one I'd get it there

https://www.amazon.com/dp/B00H9ZWLZG/ref=emc_b_5_t

Ying

Thanks @ethicalpaul , since this is bottom mount, do I need an elbow to make it stand up right or can I attached it vertically on a Tee.

ethicalpaul

Ahh I see. I think it would work in any orientation, but I would put in the fittings to make it be upright.

It should be protected from steam by a pigtail. It could be put after your existing pigtail if you added fittings there. Then you could have both the useless but apparently required one that you have now, plus the useful 0-3 one protected by your existing pigtail.

JUGHNE

Is this a side by side duplex or stacked units?
Just wondering about separate systems.....separate basements?

Ying

This is a stacked duplex. Second floor on top of first floor on top of the basement.

Whole second floor is their own unit, with separate gas and electric meter, both located in the basement too.
First floor is another unit, with access to the basement, which can be access from the outside too. One water heater and one boiler for the whole property, connected to the gas meter for the first floor.

Ying

@JUGHNE @ethicalpaul
Read ethicalpaul's thread on installing the main. Let's just said that the pictures are worth a thousand words.
https://forum.heatinghelp.com/discussion/167241/no-main-vents

Just want to make sure if I went to add a main vent on the 2 45 degree elbows that they will work, as they are below the main pipe. Won't steam push the air up the raises and still vent from the radiators and not down to the main vent that I will put in. Also how long do you think I should extend out then put in the elbow and new main vent to prevent the return water from raising and touching it since it is coming off the wet return.

Thanks

Fred

It will likely work on those 45's but I'd be a little concerned that condensate running down that pipe might cool the vent enough that it won't stay closed. If it were me, and I had to drill and tap any of those pipes, I'd do it on the nipple between the Tee and elbow that turns down into the drip or I'd even do it on the steam pipe, right before the vertical radiator run-outs. The goal is to get the air out of the main and even if it has to be just before those two verticals, the vent would have done that.

Ying

What if I took out the nipple between the last 90 drop and the first 45 elbow. Put a tee there, extend it out a little with a nipple, then 90 elbow and the main vent. Will that be a better setup? How far out should I extend for the best result?

Also should I put a nipple on the new 90 to extend the main vent to the same level or a little above the main pipes for a better result?

Only saying this as space above the main is limited, not sure I can fit new pipes ans main vent above the main pipes if just working from there.

Fred

Yes, that will work better than putting it on that 45. I'd extend it 4 to 6 inches and then go up as far as you can. Doesn't really have to be above the main, but as high as is reasonable to be able to take it out and/or replace when needed.

JUGHNE

There was a recent posting of a vent on a vertical drop that was not working. But that was the only one I recall.

But as Fred suggested you may as well go for the proper placement of the vent.

If the reducing drop 90 was removed and replaced with a tee, then a nipple with a new reducing 90 dropping to the wet return piping, reworking new 45 ells. Somewhere in there a union needs to be installed.
This will involve cracking most of the existing fittings and replacing them.
Your added tee needs at least a 3/4" branch pointing up.
Then nipple to a set of swing 90's pointing back towards the boiler to have a horizontal pipe set to drain. then 90/nipple up as high as possible for a Big Mouth air vent.
Some ceiling may have to be cut open to gain clearance.

Ying

@JUGHNE having a hard time picturing and following your suggested layout.

Essentially are you suggesting that somewhere between the second tee with the rasie going up into the ceiling and the 90 drop at the end with the middle opening of the tee facing up. Then 90 elbow on that tee opening, nipple extension, 90 elbow up then main vent? That will be it ideal set up, will have to do some measurement before new installation.

Also saw this on a recent post on the wall. Do you think I can just get an elbow like this with a opening on top and replace my 90 drop elbow and just pop the main vent on like the picture below? Thats a very short setup and Im petty sure there is space for just a main vent valve on top of my main pipes. If so what are those types of elbows called?

JUGHNE

Ying, that is technically a Tee.
Described (guessing sizes) as a 1 1/4" x 3/4" x 1 1/4" reducing tee.
First two sizes are the "run" and last is the "branch".

Usually you do not want your main vent on the last fitting as that is shown. Water surge can damage the vent as steam/water hits the back of the tee and jumps up to the vent.

If you do use the last fitting, then add the 3/4" fittings to lengthen the path that the surge would have to travel to get to the vent.

JUGHNE

I thought of this for a comparison later:

From reading about WW1 trench warfare, the trenches were dug in a zig-zag pattern. This was done so that if an artillery shell got a direct hit on the trench, the concussion (think water hammer) and shrapnel (think debris in piping) would not travel beyond the zig or the zag.
Air will still pass thru the maze of piping added for this purpose. IMO

Ying

First, big thanks to everyone that answered. The main vent is just a performance issues. I want to get back to my original reason for the thread, which is a safety issue.

So I replaced the pig tail thats on the presuretrol and put everything back on. Observing it for the a couple of days now. Gauge is still going up to 10 psi before cutting off.

Since operation is the same with a clogged and clear pigtail. Can I safely assuming faulty pressuretrol. Can I clean and reset the pressuretrol or do I have to replace it.

On a side note, the boiler does cycle of pressure. If pressuretrol is not working won't the boiler just keep running till thermostat is satisfy? What's cycling the boiler if pressuretrol is faulty?

JUGHNE

Do you have a new gauge you can trust?

Jamie Hall

Put a low pressure gauge on the same pigtail as the pressuretrol. "Trust, but verify". If it too says that the boiler is going over the pressuretrol setting, check the pressuretrol first by disconnecting either of the two wires (power off! -- put a wire nut on the loose wire!) and try to run the boiler. It shouldn't run. If it doesn't run, yeah -- probably a problem in the pressuretrol. If it does run, there's something amiss with the wiring.

Fred

Are you sure the boiler isn't shutting down because the thermostat is satisfied? How long does it take for pressure to build to 10PSI the first time? Did you check the little pin hole in the bottom of the Pressuretrol (inside the fitting that screws on to the pigtail) to make sure it isn't clogged?
I'm attaching the procedure to re-calibrate the Pressuretrol but I'd be inclined to replace it if its truly off by tht much. You can try re-calibration but it may not work:
. If you see the pressure on the low pressure gauge go much over 1.5 to 2 lbs follow this procedure to re-calibrate the Pressuretrol:
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.

Ying

Will have to get a low psi gauge then. Hardware store I check don't care them, will check a few more then just order online if can't find one. I think I did a good job cleaning the connections to the pigtail and that bottom part of the pressuretrol. The pressuretrol was click rapidly when I blew compress air through the bottom. It definitely not cycling of the tstat as when tstat comes on and off there is a loud click in the boiler room, much louder then when it is cycling off the pressure.

As for the time and pressure build up, here is what I've observed for the past hour.

Fist the boiler was off for a little over an hour as tstat temperature has been met.

Boiler turns on, and for the first 11 minutes it will sit just a little above the pin. See picture below. At 17.5 minutes it will pass 5 on the gauge and this time it cutoff at 11.5 psi on the gauge at 26 minutes.

It then will take 6 minutes 45 seconds for the gauge to drop to what I can tell is 3 psi and boiler will fire up again.

Then another 9 minutes for the psi to be back at 11.5 on the gauge.

Took a bit longer, 7.5 minutes, for the gauge to drop to 3 psi the second time around.

But a bit shorter, only 8.5 minutes, to get to 10.5-11 psi on the gauge before cutting off.

As for disconnecting the wires on the presuretrol, see picture below, the boiler did not run when I did that, but did hear a click from the pressuretrol when psi on gauge droppes to 3 again.

Jamie Hall

Sounds to me like the pressuretrol is toast.

ethicalpaul

You blew compressed air from an air compressor into the pressuretrol? Yours may have been broken already, but I wouldn't do that generally. Just applying gentle mouth air pressure should be enough to trip it for testing.

Fred

I wouldn't try to make that Pressuretrol work. Replace it. It also seems like either you are using a huge setback on the Thermostat or the boiler is way over-sized. The set back of more than a couple degrees is a No No, especially if the boiler is over sized. Have you measured your connected EDR? What is the Sq. Ft. Rating on the boiler plate?