Water hammer, capped main vent, deteriorating pipes, asbestos

tsburris

My wife and I bought a house with a one-pipe radiant steam heat system in Camden, SC in 2021.  I didn’t have a clue about radiant heat before, let alone steam.

The house was built around 1920.  The boiler system was surely not original.  The piping crosses at eye level through useful rooms in the basement, parts of the edge of the foundation were chiseled away to make room for elbows, and the upstairs fireboxes are all shallow; designed for coal-burning.  

There were 16 radiators of various sizes throughout the house - in every room and almost all bathrooms.  We removed one from the kitchen during a renovation (supply line capped with a plug), so there are 15 now.  The house is I think around ~6,000 sq ft.

Being that its South Carolina, I have had a hell of a time finding anyone that knows how this steam system works.  My HVAC guy knows less than nothing.  He put 4 inches of water in my basement (~1200 sq ft) trying to “fill the radiator back up”.  Two “boiler guys” have been by and helped with small things including a malfunctioning damper and a low water cut-off question.  I also recently had a good plumber replace ~15 ft of 2.5” black iron that had started (or had been) heating my crawl space with leaking steam/condensate.

I have replaced 6-7 radiator valves (no leaks!) and most of the vents if not all of them.  Replacing the vents was helpful in eliminating the hiss from the old stuck vents most of which I’m not sure had ever been replaced or cleaned.

The new galvanized pipe is not insulated nor was it previously.  Most of the piping in the crawl space has old deteriorating insulation that is almost surely asbestos.  Some of it - including what was replaced - is also sitting in dirt.  We dug out the dirt for the replacement 15 ft.

Having said all of that, the entire system does work.  All of the radiators radiate heat, and the boiler - thank God - has been reliable.  It is an ECR International unit from 2011.  The pressuretrol, which I recently learned existed, has been set at 8 PSI cut in since I bought the place.  I have experimented with lowering with mixed results.  5-6 seems to be a sweet spot.

We have always has some type of water hammer, but since the 15’ of new pipe went in, it’s gotten way worse - presumably because the system is now fully pressurized…?  I also recently discovered that one of the main vents - there are two; one on two different loops to opposite sides of the house - is capped.  I have no idea when or why this was done.  Is my water hammer due to the lack of insulation in the cold crawl space, or could the capped vent be contributing to it?  And does anyone know a single steam radiator specialist within 250 miles of Camden, SC?

You’d think with the exodus of folks south post Covid, there would be somebody!  LOL

Thank you for any help, advice.

ethicalpaul

There’s a lot to unpack but I’ll take the easy road and say that your pressure control is set way way too high. It should be at the bottom of its scale

Mad Dog_2

I'll try to hook you up with The Great One, Vince Fiore, NYC Licensed Master Plumber, and workaholic who is SUPPOSED to be retired in the Carolinas.  Vince, has done Thousands of steam boilers in the 5 Boros and Long Island 🏝.  If you can get him to take a ride from Wilmington NC, take advantage of his knowledge. Ill reach you and see if he's available, but he is extremely busy and in demand.  Standby. Mad Dog 🐕 

tsburris

ethicalpaul said:

There’s a lot to unpack but I’ll take the easy road and say that your pressure control is set way way too high. It should be at the bottom of its scale

Yeah. I'll try to take the cut-in back down to ~2 PSI and play with the vents. I have Vent Rite adjustable #1s on all radiators. Thank you!

tsburris

Mad Dog_2 said:

I'll try to hook you up with The Great One, Vince Fiore, NYC Licensed Master Plumber, and workaholic who is SUPPOSED to be retired in the Carolinas.  Vince, has done Thousands of steam boilers in the 5 Boros and Long Island 🏝.  If you can get him to take a ride from Wilmington NC, take advantage of his knowledge. Ill reach you and see if he's available, but he is extremely busy and in demand.  Standby. Mad Dog 🐕 

Thanks, Mag Dog.