Tapping main to add a radiator

daveamir

Hi guys my whole house is with steam but the radiator tends to short cycle often. The entire home except the living room dining room area is nice and cozy. The living room is open concept and that is we're the thermostat is . My plumber suggest to tap the main steam line with copper line to add another rad. He said a 20 section cast iron rad would help satisfy the thermostat and the boiler wouldn't short cycle as often my living dining room room is 18 by 35 feet my plumber Also suggested to change the hallway door and get a prehung door for Any draft that may come in right now I have 2 rads there equivalent to two 15 section cast iron rads thanks you guys

Jamie Hall

No. The proper and only way to add a steam line is to cut a T into that main steam line and run out to the radiator with all threaded iron pipe of the correct size. Be sure that the size and pitch on the runout is correct, and it is best to take the new line off on a T with the leg within 45 degrees of vertical.

Ironman

It sounds more like a venting issue. If you have all the original rad's connected, then why would you need another huge rad?

Steam systems (particularly one pipe) achieve balance by proper venting.

daveamir

I have a big mouth on my main and gortons on the rads iis it bad if the plumber uses copper with iron he did it once before in a bathroom that had no radiator

Ironman

Are you over or under heating in that area?

It appears that you're taking what the plumber told you as Gospel and now asking how to do it. The prudent approach would be to share what the actual problem is with us and go from there.

I'm having a very hard time swallowing that you need to add a 20 section rad that was never there before.

Jamie Hall

True, @Ironman -- and if the plumber is recommending copper, he may not be all that knowledgeable about steam, perhaps?

Ironman

@Jamie Hall
If he's recommending a 20 section rad where there was never one before, he's not knowledgeable about steam or any type of hydronic heat.

daveamir

What is the downside of the copper?

Jamie Hall

Ironman said:

@Jamie Hall
If he's recommending a 20 section rad where there was never one before, he's not knowledgeable about steam or any type of hydronic heat.

I was trying to be nice!

nicholas bonham-carter

The excessive expansion and contraction of copper will make the joints prone to failure and leaking.
Iron pipe is the way to go, but will that size of main handle the extra steam needed?—NBC

daveamir

He recommended it because I changed my main vent and all my air vents on the rads all thevrads heat up pretty evenly and they all get pretty hot, all the rooms get warm except the living room and dining room it is a very big open area and it always has a hard time getting hot that is were thevthermostat is located so while the boiler is working to get the living room up to temp every other room on the house is warm, I have poor insulation but can't rip walls out at this point so this was his suggestion to get the living room hot at the same time as every other room venting doesn't seem to be an issue as all rads get super hot at a decent amount of time

daveamir

Thanks Jamie I appreciate it I am just trying to understand I appreciate everyone's feedback

Ironman

You're probably venting your other rad's too fast and the ones in question not fast enough.

The dead men that did steam were very competent and meticulous about sizing radiators and piping. Unless you've drastically changed the envelope of the rest of the house while not changing this part, the radiators are properly sized. The dynamic that's changed is the type of firing of the boiler. When it was coal fired, the heat was very even and slow. Less venting was necessary. When an oil or gas burner was added, that dynamic changed to where the firing rate was higher and cycled instead of being steady. The solution is PROPER venting to match the firing of the boiler.

The mains should vent fast and the rad's slowly. It sounds like you need to slow down some of the rad's that are venting quickly. Just because you have Gortons on them doesn't mean they're venting at the right rate.

Fred

How old is this house? Not many older homes, with steam heat had open concept areas. Was the house renovated at some point and radiators taken out of the area in question?

daveamir

1925 the previous owner made the living room and ding room into open area before there were kind of separated looks like rads weren't touched

daveamir

What do you think of this ?

Fred

sooner or later those copper joints will crack from expansion and contraction. Also, If you or your plumber think a 1" pipe will feed a 20 section radiator, it won't happen. A 1" pipe will reliably support 25 to 30 EDR, if this is a one pipe system. There has to be room for condensate to return, in that pipe.

daveamir

That sucks so I should get a plumber to switch out to black iron ? this is for a 4 section radiator

Fred

At this point, you can either wait until it starts to leak and plan for a full replacement at that time or you can be proactive and go ahead and replace it. It will ultimately give way.

daveamir

Ok what should I have on hand to cap it when it eventually leaks so I won't be stuck thanks so much

daveamir

Forget adding a radiator I now see this plumber doesn't know what's what

Fred

Depending on where it cracks and how bad the crack is, you can have a saddle clamp that has a steam rated rubber liner to put over the joint or, the safest bet is to have a plug that fits that tapping and when it starts to leak, turn the power off to the boiler so there is no steam, cut the copper pipe so you can unscrew that copper fitting and replace it with the black iron plug. That will let you run the boiler, minus that small radiator until you can have the piping replaced.

daveamir

Thanks Fred here I thought I had a nice set up ok I will get that plug thanks

Jamie Hall

Don't feel badly, @daveamir -- many plumbers, even very very good ones, don't really know and understand steam heat, and they tend to do what they know best. No blame to them for that. If he did a good job of those solder joints, they may well last for years.

However, it is not the really right way to do it.

Do check your heat losses and adequacy of the radiators -- and the venting. As @Ironman said, it wouldn't be too surprising if you could make real improvements just by making sure the mains are adequately vented and by adjusting the venting on all the radiators.

daveamir

I have a big mouth on a 2 inch 5o foot main I gorton no c on the radiator farthest from boiler on the first floor then a gorton no 6 in dining room and 2 gorton no 5 in the kitchen and bathroom radiator upstairs on rad farthest from boiler on master bedroom I have a no 6 then middle room a no 6 then bathroom no 6 then the last upstairs room which is directly above kitchen which is closet to radiator I have a gorton no c what do you think

Ironman

Not enough info. We need to know the EDR of each rad and if any of them have long risers.

daveamir

How do I calculate plz

Chris_L

I wouldn't worry about the existing copper line. But wouldn't use one for a new radiator, either.

Before I knew anything about steam (or this site, if it even existed then) I let a plumber add a new radiator piped with a copper run-out from the main. That was at least 20 years ago. Hasn't leaked a bit. I'll worry about it when it happens. And then use threaded pipe to fix it.

What the copper does seem to do is muck up the float type LWCO more. I have two of the same boilers, and I swear the LWCO on the system with the copper line gets fouled up more than the one that doesn't have any copper piping. (Open the ball valve on the LWCO and nothing comes out.)

MilanD

Google "calculate radiator edr". It'll give you explanation. (Sorry, I'm on my phone and it won't let me insert pdf urls.)

Ironman

EDR tables:

http://www.uticaboilers.com/sites/default/files/Radiation Tables.pdf