Gortons spitting on cold start

aat879

I've been dialing in my venting this winter to better balance our steam system. To do that, I've spent the money on Gortons for (so far) five radiators with the appropriate venting rates. Everything was working great. Yesterday, unbeknownst to me, my kids played with the radiator and lowered the temperature down to the 40s, so the system went cold and fell from 70 (our preferred set temp) to 65. I didn't notice because we had a warmish day yesterday. This morning I bumped up the tstat to 66 to get the system up and going again. As with other cold starts, the system has to get a ton more air out than usual.

The issue is that all of the radiators with the Gortons are (as I write this) going nuts spitting air and steam. It seems none of them closed. The other vents on the other radiators, which are Hoffman 41s, close as usual and are not making noise.

This is quite frustrating. I paid good money for these vents and kind of expect them to work properly and close Our pressure is set at .5 lb cut-in with a 1 lb differential. Unfortunately our boiler doesn't have a pressure gauge with a lower read, so I can't tell if the pressure is actually going higher than 1.5. I service the boiler dutifully every year, so there's no issue with the pigtail.

Is it normal for Gortons to be have this way? If it were one I'd say it's a bad vent. But all five tells me it's not a coincidence. Any info or advice?

ethicalpaul

Something else is going on

As with other cold starts, the system has to get a ton more air out than usual.

This isn't true. The system has x amount of volume in it for air or steam, this isn't affected by how cold the system is. Within a few minutes after any call for heat ends, the entire system is full of air.

Can you clarify for me a little? Are you saying that the long call for heat to recover your temperature led to all your radiators being completely full of steam yet you saw the Gortons not closing?

Describe what you normally see on a normal call for heat in your system. In my system, the radiators may not heat all the way across to the vent, for example.

Jamie Hall

What pressure did the system get up to on that long call?

EBEBRATT-Ed

I suspect the long recovery on the unintentional set back contributed to the issue.

Your system can't contain more air than it normally does.

I would suspect the pressure rose above normal on a long run. I would install a low pressure gauge so you can tell.

lets see some pictures of the boiler and near boiler piping and check the pitch on all radiators.

RTW

For what its worth, I have slowly graduated an increased temperature two degrees at a time if starting from low fifties to a goal of 60 or 62( much higher than that my house feels like a sauna). I cant explain why, but it seemed steam system needs some delicate care and this method worked for me in a single pipe residential system

All the best,

RTW

Waher

I think your pigtail may be clogged and the pressurtrol isn’t shutting off the burner above the set pressure because of it.

EBEBRATT-Ed

@Waher

Could be but the OP said he already checked the pigtail

delcrossv

I've had a series of "out of the box" failures with Gortons, but all of them? That's surprising.

Jamie Hall

The thing that concerns me here is that "spitting" is indicative of wet steam or excess pressure — or both. So it seems to me that before we throw the messenger under the bus here, we need to be quite sure that on a long recovery run the pressures are good (under 2 psig) and that the steam is quite dry.

dabrakeman

In whatever order you want, double check the pigtail, get a 3psi or 5psi gage and unscrew the Gorton valves and test them with the blow test (should close when upside down).

If you were at 65deg at the thermostat and just set the thermostat up to 66deg it doesn't seem you should have built a lot of pressure unless you are quite oversized. Are you?

aat879

An update: After about maybe 15 minutes of spitting steam, all of the Gortons went quiet seemingly at exactly the same moment. I'm guessing, if it was a pressure issue, it's because the pressure dropped enough for their liking. The system has been running just fine since. Except for a slight imbalance in how the radiators heat up, but that's because I was and am still trying to dial in their vent rates.

Thanks to everyone for the flood of responses. Will try to reply to as many as possible with names linked.

@ethicalpaul, thanks for the point about the air. I always thought that, when the pipes go cold more steam condenses than usual and pulls more air in. In any case, the system always seems to work "harder" when it starts from cold and has to climb a number of degrees after a setback. To answer your question: On a normal call for heat, nearly all the radiators heat up, partially when the weather is a little warmer but all the way across when colder. The heating is not always consistent from cycle to cycle, though, and I think that's because I haven't quite dialed in the venting. In any case, the system is totally quiet and there is no spitting or hissing of any kind.

@Jamie Hall: I can't answer your question about what pressure the system got up to on a long call because I don't have a low-pressure gauge. I hope to remedy that so I can see whether the pressuretrol is failing. In any case, the pressuretrol is set to cut out at 1.5, so if it's working correctly, the system should not get over 1.5 psi before shutting off, right? I don't think that pressure is high enough to overwhelm the Gortons, is it? As far as dry steam, what might cause that? The boiler was sized new based on radiator measurements, and the near-boiler piping is done properly with a drop header as illustrated here. Outside of this cold start episode, I've never had any evidence of wet steam.

@EBEBRATT-Ed The lower-than-normal pressure is my suspicion too. Would that mean that the pressuretrol is failing to cut off at 1.5 psi? I hope to get a low-pressure gauge installed and perhaps a vaporstat to lower the operating pressure even more. I can send some pictures later of the near-boiler piping, but the piping is done properly as I indicated in my response to Jamie. The pitch of the radiators is right, I've checked.

@dabrakeman Oversized boiler? No, it's sized right. I'll double-check the pigtail. The Gorton vents pass the blow text, both right side up (they pass air) and upside down (they close).

Not sure if I have provided any further useful info. Grateful for any more feedback.

Long Beach Ed

Post a photo of the boiler piping. Without that we're guessing.

Measure the pressure when the vents are spitting.

Are you certain that the vents aren't just venting air? Is the body of the vent too hot to touch? Is steam coming out of it or just hot air? Vents vent air, and it can be noisy and wet at some times in some systems. You may want to check the temperature of the vent's case with a thermometer of sorts or temperature crayon.

dabrakeman

If the only slight issue you have is during recovery then break up that recovery into two or three stages (start it earlier in the morning so yo0u can still reach your target when you want it).

ethicalpaul

 I always thought that, when the pipes go cold more steam condenses than usual and pulls more air in. In any case, the system always seems to work "harder" when it starts from cold and has to climb a number of degrees after a setback.

When the pipes go cold, they do use more steam to heat up, but this is unrelated to the air. There is no pulling air in during a call for heat.

Steam systems never work harder. They just happily produce x amount of steam over time. That steam pushes the air out of the main pipes via the main vent(s), heating the pipes as it goes, then pushes the air out of the radiator pipes with the air escaping from radiator vents, then the steam finally starts to enter the radiators, heating those basically section by section, pushing the remaining air out of the radiator vents.

When the radiator vents close, almost all of the air is out of the entire system and the condensing steam creates areas of low pressure that pull more steam.

ARobertson13

A statement was made about a blow test " The Gorton vents pass the blow text, both right side up (they pass air) and upside down (they close)." This test to determine if the vent will close is not valid. Turning the vent upside down to see if it closes will only determine that the vents will close if the expansive element [canister or bimetallic strip] will move far enough and apply enough pressure to keep it closed when heated by steam. I have dozens of vents that close when air is blown into it when upside down but not when heated, See discussion " Vent testing and repair"

Waher

it’s possible the pressuretrol isn’t calibrated properly so that it may be set correctly according to the scale, but not cutting out at the desired pressure. The only way to set a pressuretrol accurately is to install a 1-3psi low pressure gauge and make adjustments to the settings based on the gauge readings.