Broken Pressuretrol?

WindyT

Hi,

This forum was very helpful as I tried to learn the system in our house last winter, which was our first winter in our 1925 house with steam heat. Though we were able to stay warm there are some problems I'd like to diagnose and correct sooner than later as we prepare for next winter.

We had significant water loss, particularly when cold. There is no automatic feed, and on the coldest days of the year I had to refill the water every day or so, and on more normal days it was every few days. I found it to be much worse when I tried to set the system to be a bit cooler during the day and overnight, and warmer in the morning and evening.

I'm thinking our pressuretrol might be broken and may request it to be replaced in addition to our regular annual servicing, but am looking for second opinions about other potential problems that could cause our issues:

1. Aforementioned water loss
2. The system only ever shuts off when it reaches the thermostat temperature, even if that takes 45-60 minutes. It never shut off because it hit the pressure cut-off on the pressuretrol.
3. Once all of the radiators heat and when the air vents should be closed, there is hissing and occasionally a little water spitting from multiple radiators. I've replaced the vents on most of the radiators with new gortons but it keeps happening.
4. I think most of the water loss is from shut-off valves leaking. Midway through winter I realized one shut-off valve was leaking, especially when I would raise the temperature on the thermostat and the system was on for a longer period. It was replaced and doesnt seem to leak now, but through the winter I realized at least 3 others would leak once the system had been on for 30-40 minutes at a time.
5. The pressure gauge would start off at 0 psi and stay near there when some of the radiators were still heating, but once all are hot it rises steadily to (I believe) 2-2.5 psi.

6. Pressuretrol pigtail was checked by technician midway through winter who thought that might be the issue, but it was clear. He also adjusted the pressuretrol down to where it is now: Main - 1 psi, Diff (subtractive) - 0.5 psi (though it wasn't much higher before this)



Thank you!

EBEBRATT-Ed

The pressure control is not your issue. Contrary to what you read on some posts here, the pressure control only shuts the burner down if the pressure is too high. If the house heats without tripping the pressure control that is good IF you think the pressure control is not operating properly. Use a 0-5 psi gage for this in addition to the 0-30 psi gage you have to check the control settings. the scale on the control is unreliable

Have you teck overfill the boiler with water while it is off and is cold. fill it above the gage glass until the first section of the supply pipes are cold and have water in them. let the boiler sit. your looking for leaks and/or water on the floor.

Then drain the boiler down to a normal level and run it. chech the system for leaks and check the chimney for any white smoke. the water is going somewhere

WindyT

No white smoke - the plumber and I both checked multiple last times last year. He also at first initially though it could be a crack/leak somewhere around the boiler, but he couldnt find any evidence. I question the pressure level because it seems like even when I’ve I’ve things I thought were malfunctioning (vents), the replacements have the same issues, maybe because the pressure is too high?

I can try the water fill test just to confirm there isn’t an issue there - I take it it shouldn’t be too difficult to do myself

Jamie Hall

What @EBEBRATT-Ed said. Get a reliable 0 to 3 psi gauge and add it to the system (keep the 0 to 30 -- the insurance and building code folks want it) and run the system. That will tell you what the pressuretrol is actually doing. It should shut off at 1 psi and come back on at 0.5 with the settings you have.

Now, that said, that's not the problem with the water loss -- which is excessive. Somewhere you have a leak, or leaks. If you had a really bad boiler leak, yes you would see white billowing steam out of the stack. But it takes a pretty bad one to do that. The overfill test is the best one for the boiler and the wet returns.

ethicalpaul

There are several things to unpack in your post, and others are working away at those, but one thing caught my eye:

4. I think most of the water loss is from shut-off valves leaking. Midway through winter I realized one shut-off valve was leaking, especially when I would raise the temperature on the thermostat and the system was on for a longer period. It was replaced and doesnt seem to leak now, but through the winter I realized at least 3 others would leak once the system had been on for 30-40 minutes at a time.

What shut-off valves? You suspect these as the source of water loss, but where is the water going?

WindyT

> @Jamie Hall said:
> What @EBEBRATT-Ed said. Get a reliable 0 to 3 psi gauge and add it to the system (keep the 0 to 30 -- the insurance and building code folks want it) and run the system. That will tell you what the pressuretrol is actually doing. It should shut off at 1 psi and come back on at 0.5 with the settings you have.
>
> Now, that said, that's not the problem with the water loss -- which is excessive. Somewhere you have a leak, or leaks. If you had a really bad boiler leak, yes you would see white billowing steam out of the stack. But it takes a pretty bad one to do that. The overfill test is the best one for the boiler and the wet returns.

Filled the boiler up to the risers today and let it sit for an hour - no water anywhere on the ground that i could see. Took the front panel of the boiler off and everything was dry around the burners.

Is the 0-30 psi 'internal syphon' that reads at 2.5 psi when things are cranking not accurate? Or is it not connected directly to the pressuretrol's settings?

WindyT

> @ethicalpaul said:
> There are several things to unpack in your post, and others are working away at those, but one thing caught my eye:
>
> (Quote)
>
>
> What shut-off valves? You suspect these as the source of water loss, but where is the water going?

The valves at the base of the radiators where the steam pipes come up and connect. One was replaced last year because it was obviously leaking. Didn't catch it for the first couple months because it is hidden behind a wall.

However, after one radiator was fixed that I noticed that at least 3 other valves would also leak when the system was running for a long time - after 45 mins or so. It might've been more than 3, but I can't quite remember from last winter. Only once steam reaches all of the air vents and they close do valves on some of the radiators start leaking. I noticed late in the heating year so was wrapping the leaking connections in small towels, which would be soaked on particularly cold days.

The thing that led me to question the pressure is that early in the year many of the air vents were spitting water and/or steam even after they should've been closed. I replaced the air vents but the issue kept happening. Would this many vents and valves all be failing at the same time, or could the failures be caused by higher than normal pressure?

nicholas bonham-carter

High pressure can destroy air vents, so the 0-3 psi gauge is essential, and should be put on every steam boiler, alongside the useless 0-30psi gauge.—NBC

Fred

A 0-30PSI gauge is very inaccurate. It may read a pound or two when the pressure is actually 10PSI. That may, by itself be the reason you see leaks around valves. Put a 0-3 PSI gauge on the boiler, clean the pigtail that the Pressuretrol is mounted on to make sure it is not clogged and retest the system for leaks.

ethicalpaul

Thanks @WindyT yes, leaking radiator valves are no fun. As the others said, if there are high pressures the vents can fail.

I wouldn't expect the valves to fail from the higher pressure, but it doesn't help! The valves will probably still leak at normal operating pressure if they are leaking now, and they'll have to be addressed I think regardless.

ChrisJ

Fred said:

A 0-30PSI gauge is very inaccurate. It may read a pound or two when the pressure is actually 10PSI. That may, by itself be the reason you see leaks around valves. Put a 0-3 PSI gauge on the boiler, clean the pigtail that the Pressuretrol is mounted on to make sure it is not clogged and retest the system for leaks.

Fred,
I would expect a 0 - 30 PSI gauge to read 10 PSI very accurately, it's a third of it's scale.

When you get down to a pound or two it's going to be off a decent amount, but I'd expect it to even read 5 PSI respectably. Chances are if it says 2 - 3 PSI, that's probably close enough. I had a 50 PSI gauge on my pool filter and it even was reading 4 PSI fairly accurately. It died, so I installed a 30 PSI gauge and that too isn't having an issue with 4 PSI.

Assuming the gauge is in good working order of course.

@WindyT What valves are leaking and where? Do you mean the radiator shut off valves? Are they leaking at the packing nut (where the shaft comes out) ? If so you can try snugging those nuts up a little and see if it stops.

Jamie Hall

And if it reads 2 to 3 psi when the system is running, and 0 when it's off and cold, it's probably not lying. Too badly anyway. And the operating pressure is too high, which isn't helping the steam leaks any.

Fred

@ChrisJ , like we've learned with Pressuretrols and Vaporstats, the accuracy of these gauges is only as good as the calibration out of the factory and most Homeowners don't realize they more often than not need to be calibrated or how to go about doing that.

Grallert

Any buried return lines?

KC_Jones

I think a change of perspective is needed here. I doubt the controls have any issues.

I think with all the leaks, and with adding water that often there are a bunch, the system is incapable of building any pressure so the pressure safety never activates.

Also to be clear to the OP, pressure is bad, that isn't a control it's a safety. So on a properly sized system that isn't leaking the performance you are seeing is desirable. On your system it is showing the leaks.

On mine, and many systems, a morning recovery of 3 degrees results in almost zero pressure and no shut downs from the pressure safety.

Again pressure is technically bad.

IMHO if you are adding water more than once per month, you have a problem that needs addressed. You are adding water almost daily and that will drastically shorten the boiler life.

ChrisJ

KC_Jones said:

I think a change of perspective is needed here. I doubt the controls have any issues.

I think with all the leaks, and with adding water that often there are a bunch, the system is incapable of building any pressure so the pressure safety never activates.

Also to be clear to the OP, pressure is bad, that isn't a control it's a safety. So on a properly sized system that isn't leaking the performance you are seeing is desirable. On your system it is showing the leaks.

On mine, and many systems, a morning recovery of 3 degrees results in almost zero pressure and no shut downs from the pressure safety.

Again pressure is technically bad.

IMHO if you are adding water more than once per month, you have a problem that needs addressed. You are adding water almost daily and that will drastically shorten the boiler life.

If we have a really cold month I've been known to add twice in a month.

WindyT

> @Grallert said:
> Any buried return lines?

Nope! So at least I know the return lines aren’t leaking

WindyT

> @Jamie Hall said:
> And if it reads 2 to 3 psi when the system is running, and 0 when it's off and cold, it's probably not lying. Too badly anyway. And the operating pressure is too high, which isn't helping the steam leaks any.

That’s what I was thinking. I fired up the system over the weekend so I could test again and remember which radiator valves were leaking, and the gauge immediately went to 10+ psi, which I assume to be a malfunctioning gauge. Shut it off and will deal with the gauge first...

ChrisJ

WindyT said:

> @Jamie Hall said:

> And if it reads 2 to 3 psi when the system is running, and 0 when it's off and cold, it's probably not lying. Too badly anyway. And the operating pressure is too high, which isn't helping the steam leaks any.



That’s what I was thinking. I fired up the system over the weekend so I could test again and remember which radiator valves were leaking, and the gauge immediately went to 10+ psi, which I assume to be a malfunctioning gauge. Shut it off and will deal with the gauge first...

Or you have really inadequate main venting........
Do the vents make noise during this? Hissing? Whistling?

WindyT

> @KC_Jones said:
> I think a change of perspective is needed here. I doubt the controls have any issues.
>
> I think with all the leaks, and with adding water that often there are a bunch, the system is incapable of building any pressure so the pressure safety never activates.
>
> Also to be clear to the OP, pressure is bad, that isn't a control it's a safety. So on a properly sized system that isn't leaking the performance you are seeing is desirable. On your system it is showing the leaks.
>
> On mine, and many systems, a morning recovery of 3 degrees results in almost zero pressure and no shut downs from the pressure safety.
>
> Again pressure is technically bad.
>
> IMHO if you are adding water more than once per month, you have a problem that needs addressed. You are adding water almost daily and that will drastically shorten the boiler life.

Thanks for this perspective - makes sense. The gauge almost immediately showed 10+ psi when I fired it up this weekend, I’m thinking first steps should be to replace the gauge and either tighten or replace all leaking radiator valves, and see if that solves my issues.

I have a (new) plumber coming out this week who is recommended locally for steam heat. I previously used one last year who is also highly rated for steam systems and is active on this board, but my issues were unfortunately never really resolved. Long term I’d like to be able to do fixes like this myself, but time is unfortunately scarce right now.

Want to solve these issues sooner than later both for health of the boiler and so we can take trips in the winter without worrying that we’ll end up with frozen pipes because the heat shut off...

WindyT

Turns out it was the boiler, after all.

Had a plumber out today - he found evidence of a cracked section with rust above and on the burner below it. Thought we'd have a few more years since the boiler is only 9 years old, but if the previous homeowners had leaks they didn't fix and kept adding water, I guess it makes sense.

Will work on sealing up all the valve leaks when the boiler is replaced so we end up adding a lot less water and oxygen to the system.

Thanks everyone for the help and ideas.

nicholas bonham-carter

Make sure the new boiler is properly sized to the radiation EDR, and not merely to the nameplate of the old one.
You probably will need new main, (not radiator) vents, as well as a low pressure 0-3 psi gauge.—NBC