All radiators hiss/spit since gas line replaced

albuchsbaum

I have a 13'ish year old Weil-McLain EG-65 gas boiler, one-pipe steam system; mains and all radiators vented with Gorton vents; all valves are fully open. No auto-feed.

Worked flawlessly until this year, quiet as a mouse. Minimal water loss. I added a small amount of water once or twice a month, while draining normal sludge. No chemicals except for a Tbsp. of TSP once or twice a year to keep the pH slightly above neutral.

Prior to the start of this heating season, PSE&G ran a new gas line from the street to my house, as part of a neighborhood project. Nothing inside the house was changed. Since the start of the season, every time the heat comes on so that the radiators heat fully across, *every* cast iron radiator hisses and spits while the system continues to fire, like there's wet steam, except there is no sign of surging: the water level fluctuates about .5 inch while the system is running, as it always has. There's no water hammer, either. I do have a few convector radiators, which don't hiss/spit; and the main vents do not hiss/spit either.

To date, I've:
- flushed the boiler and wet return.
- replaced all the radiator vents.
- replaced the pressuretrol and cleaned the siphon. System is set at 1.5 ppsi cut-out, .5 cut-in, which is as low as possible.

My plumber has blown down the boiler as well, and we both saw the water come of the top clean. He suggested adding Kek, which I did, but that hasn't helped either.

I'm attaching pictures of the boiler and near-boiler piping. Nothing has changed since installation except the gas line, and PSE&G came back to measure the flow, showing that the boiler was getting the proper 250 kBTU. All radiators heat fully across. I do notice that since the gas-line replacement this happens faster (within 30 minutes from a cold start in the morning, even on the coldest day of the year, vs. an hour or more before). Also, I will regularly see high-pressure cycles, which almost never happened previously.

Would appreciate suggestions. Thank you!

Fred

It's not piped correctly but, if it worked adequately before the new line, and you know the Pressuretrol is good and the pigtail is clean and the vents are good, my suggestion is for you to calculate the total EDR of all of your radiators and compare that to the net SQ. FT. of steam on the rating plate of your boiler. The boiler may well be significantly over-sized. It sounds like with the old gas line, they may have been running a reduced pressure and that may have made your boiler act like it was down fired. With the new gas line, they may be running at a pressure that feeds your boiler at the rated pressure/volume to fully fire it to its specifications.

ratio

What @Fred said. From the outside, there isn't anything PSE&G could have done except increase the gas pressure to the house, or rather (I suspect) raise it up to where it was supposed to be. That fits with the shortened time to heat as well. I don't know the relationship between BTU input and time-to-boil, but if it's twice as fast now that makes me think she's burning twice as much? You may want to have a good steam guy take a look at it. Do you have a house regulator out by the meter? Is it new or old?

The local gas utility came through my neighborhood several years ago & pushed in a new high pressure service line down the street, we all got house regulators. They did the same at my church a few blocks away, but somebody screwed up the work order & they installed a 2# system instead of the 7 in wc we were supposed to get. I was NOT amused; & spent some time on the phone with them.

albuchsbaum

Thank you both!

I will do the EDR calc and report that tomorrow.

There is no regulator on the house.

EBEBRATT-Ed

If they ran a new service there has to be a regulator on the house. Need to have the gas pressure checked at the inlet to the gas valve and on the burner rack.

As others have suggested you may have had "low" gas pressure originally and with the new line the pressure has increased slightly (although this shouldn't have affected burner pressure, unless the burner gas valve regulator was originally cranked to the extreme so it can't regulate).

I will bet they checked the house pressure but did they actually check the burner rack pressure?? usually 3 1/2" wc

combustion should also be checked with an analyzer

albuchsbaum

Thanks again for the advice. I calculated 483 sq. ft. EDR to the radiators (10 sections of 5-tube 38", 124 sections of 5-tube 20", and 46 sections of 5"x20" wall). I'm confused on the pickup factor. If you're supposed to multiply that by 1.33 for the piping, then the EG-65 is perfect (650 sq. ft.); if not, then it's too big. If too big, can this be compensated for by a pro (short of replacement)?

It was explained to me by PSE&G that no regulator was needed, because the new service is still low pressure.

nicholas bonham-carter

Your square feet calculations for the radiator should match closely the rating plate on the boiler, with no 33% increase (feet to feet).
That increase is only used comparing the BTU rating of the boiler to the BTU ratings on the radiators. Many people think the 33% percent is really too high for most applications.
Next step would be to have the burner rack pressure tested so as to make sure that the burner is not getting more gas pressure than it should.--NBC

ratio

The EDR number on the boiler has the pickup factor cyphered in already. A direct comparison will show you how far oversized you are.

It would seem that the boiler can indeed be downfired enough to adequately meet the attached load, as that is what you described it doing before the gas line rework. It should be able to do that again, HOWEVER it MUST be done by an experienced tech WITH THE PROPER TOOLS, i.e. digital combustion analyzer.

It's possible that this work is outside the experience of your current plumber, as it seems he vetted steam piping that isn't up to mfgr's specs. Or, perhaps he wasn't concerned with it, as it seems to have worked more–or–less properly previously.

I'd imagine you're good without a house regulator. The liability is far too great for the utility to get it wrong—even a lousy lawyer would get you the company jet if they screwed that up!

Fred

As has been said, If you connected radiation has an EDR of 483 and the boiler plate says 650 Sq. Ft. of steam, the boiler is over-sized. It is a direct comparison between the Boiler plate Sq. Ft. of Steam and your calculation. Where are you located? Maybe there is a Steam Pro here who can look at down firing it enough to get you back to where you need to be. Maybe even put a two stage gas valve on the boiler if need be. Absolutely no need to replace the boiler until it dies. At that time, replace it with a boiler sized as close to the 483 EDR you calculated and have the piping install correctly.

albuchsbaum

Thank you, all. I appreciate the feedback. I'm in Madison, NJ.

Would it make sense to redo the near-boiler piping?

GW

Looks like the boiler wasn't installed well, but if it worked before then I'd say you're burning more BTU now. Get someone that knows gas and combustion and see if they can bring the gas pressure down a bit. If not and you're oversized you probably need to repipe the boiler. Maybe dumb luck worked until the new gas line was installed. Without gas pressures known (before and after) it's hard to make educated comments

Fred

There are a number of great steam Pros in NJ. Maybe @Dave0176, @EzzyT , @Danny Scully (I think) will respond and you can schedule one of them to look at your boiler and let you know what should be done.

Steamhead

Fred said:

There are a number of great steam Pros in NJ. Maybe @Dave0176, @EzzyT , @Danny Scully (I think) will respond and you can schedule one of them to look at your boiler and let you know what should be done.

This.

Danny Scully

While I'm flattered to be grouped with the likes of @Dave0176 and @EzzyT, my company's service areas is Long Island, NY. More specifically Nassau County. Thanks for the consideration though!

EzzyT

@albuchsbaum send me a private message and maybe we can set something up

Abracadabra

It's possible a main vent has failed or stuck closed from last season.