Conversion to Gas - two systems to one.

raemac

I have a two family home that had 2 seperate oil/steam systems.  I converted to natural gas and was talked into converting over to one system with zones and thermostats for first and second floors.  It is a one pipe system. They just finished and I have water pouring out of the radiators on the first floor and very loud/violent water hammer.  There is 1 ventrite #77 on end of each main - see picture.  Mains look like they are pitched right but I am concerned about decision to combine the two systems.

question - should I have combined systems?

question - should mains have more than 1 vent.  is current vent ok?

question - if one floor calls for heat, what happens to water condensing in pipes as it travels back to boiler?  will it get pushed thorugh system and out to radiators?

thanks

        

BobC

More information

How did the systems work before the work?



What does the pressure gauge on the front of the boiler read when it is making steam?



What is the pressuretrol set to?



Is the water in the sight glass bouncing around a lot?

 

Did the installers replace or clean out the return pipes? How did they join the two returns? It has to be done below the water line of the boiler or else the symtoms you describe can occur.



I suspect the boiler has to be skimmed to clean the oils out of it. All newly installed boilers have to be skimmed to clean them.



Main vents have to be sized for the length and diameter of the mains. The piping on the boiler header looks a bit odd can you take some pictures from a different angle? We also need a picture that shows how they joined the two mains and the two return lines.



Bob

JStar

Zoning

Zoning steam is not as easy as throwing on a couple of valves. It has not been installed correctly and needs to be rectified.



Can you take more pictures from the front of the boiler?

Paul48

?????

Traps on the drips of counterflow? Hard to see...

EBEBRATT-Ed

zone valves

putting zone valves on changes everything. More of a condensate problem than anything. Water will back into the system that is not heating. You may need to do a lot of work to this system to make this work correctly. Need to dig out Dan's book "Lost Art" and read up on this myself.

Ed

raemac

updated pics

thank you very much for the reply. I have added some pictures which I hope are what you need.  They are coming back tomorrow morning to address the issues.  Each main is at least 4" diameter and about 60 feet long as it does a rectancle around the basement.  Any thoughts about more than 1 vent?

raemac

zoning problems?

thanks Ed,

Has anyone else had good luck with zoning the steam heat off of 2 mains? 

BobC

4 cu ft per main

60 ft of what might be 3-1/2 pipe contains 4 cu ft of air; the Ventrite 77 is rated for 0.2cfm, you probably need 10 times that amount of venting. 2ea Gorton #2's on each main might be a good starting point. I hope the pressure is set very low.



As to the zone valves and traps, I don't really know how that could work, not that it can't, I just don't know.



Bob

Paul48

Looks all Wrong

I'm waiting to hear the steam guys comments.

Paul48

?

Dripped counterflow with traps and dry returns? I can't figure that out.

Rod

Steam Zones

Hi - First of all I must state that I’m only a homeowner and not a steam pro so please keep that in mind when reading the comments below.

    From the reading I’ve done, my understanding is that it is very hard to make a gravity system work with zone valves.

When the zone valves are open, it runs like a regular gravity system and you only have to worry about the “A” dimension but when the zone valves shut, you get into a “B” dimension situation which for 2 PSI is 60 inches above the boiler’s waterline!  To make this work I think you’re probably going to need a condensate tank & pump. This is all covered in Dan’s “The Lost Art of Steam Heating”, Chapter 11, which if you don’t have it is available in the Shop section of this website. Ii maybe that your steam guys don't realize that with the zone valves they are creating a "B" dimension situation.



The header needs reworking - as it is setup now, it isn’t helping you get dry steam. I’d use a larger header pipe and use individual risers off the top of the header going up to each of the mains. I’d place the zone valves higher up so that condensate on the boiler side of the valves would drain back and on the steam main side of the valve I would use a full sized tee for a drip rather than the dripped elbow you have now as from what it looks like in the pictures, the elbow doesn’t fully drain away the condensate trapped when the zone valve is closed.  



Vents ? - With a condensate tank that taken care of by the tank vent.

Again please keep in mind that the comments above are from an amateur. Like others I too will be interested in what comments the pros have as they have the experience to better judge what will work and what won’t.

- Rod

Charlie from wmass

bad idea

My head hurts trying to trace the piping. Two boilers, each floor pays their own heat bill, systems get balanced well, everyone is happy. This is a bad idea imho. Banging is your system crying for help.