Residential Steam boiler

delta595

ok, I'll try and get someone to stop by and take photos' today. will definitely keep you in the loop

ethicalpaul

After the other radiators get warm this one starts banging, shooting hot water then steam comes.

This is potentially a very important detail. Would you say it's not until some or all of your other radiators' vents actually close from steam that the problem one starts spraying?

This would make sense because at that point, a lot more of the produced steam would be forced up to that one remaining open vent.

If you are in a mood to experiment, rotate the problem radiator's vent upside down and see if the spraying problem moves to a different one. This would help to rule out a problem with that radiator/its supply.

Chris_108

Paul, in that video you posted, can you explain why that water is surging so violently? Is it because the riser is not long enough to build up steam?

I am a residential Landlord with several buildings (including my primary residence) having older single pipe steam as heat source and have learned quite a bit here...

As for OP water issue, I agree that most likely not a clog in the piping but I recall one time I had a radiator that would not heat up and I Was convinced there was a blockage somewhere (after all 80,90 year old piping sounds logical right) so I got a compressor opened up the radiator valve and blew air through the valve and clearly was getting air back to the NBP with no issue.

I feel for you though, 2 gallons of water on 2nd floor is no fun. Good luck

Chris

ethicalpaul

No, the height was enough if the piping would have been correct.

Mine was doing that because of some or all of the following reasons:
- it was a Dunkirk design side-supply boiler with only one side piped
- it had a poorly-piped “header” (but it was even worse before I improved it)
- the water was always dirty from years of mud buildup that I never could clear

In the next video I lowered the water level just a little and it stopped carrying over: https://forum.heatinghelp.com/discussion/comment/1551477/#Comment_1551477

SteamingatMohawk

I've been following this discussion off and on for a while. If I remember correctly there have been comments about steam rising, holding the condensate back. The OP said he has VariValves installed and has tried the full range of settings. He also said he has removed the valve and got the same noise.

As mentioned in other discussions, Varivalves (Heat Timer) have a lot of capacity and the minimum position does not shut the valve completely off. It passes about a #5.

There were some comments about slowing down the venting, perhaps, the minimum setting on the Varivalve is too much and a smaller vent is needed.

If my recollection is accurate, I suggest replacing the Varivalve with a VentRite#1, because they can be completely shut off and their maximum capacity is around a #5. Any other decent quality valve that can pass less than a #5 might also work. A MoM with a #4 orifice might work, but that's as small as MoM sells. That's why I recommend the VentRite#1.

I can post my comparison chart that some of you may have seen in another discussion, if that is desired.

@Jamie Hall , @ethicalpaul and the other real experts, what say you?

BobC

If your using Heatimer Varivents they can vent air very fast and produce a lot of condensate and they are hard to adjust at the low end of the range. They also can't shop water from shooting out of the vents. Gortons, maid o mist and hoffman's all have floats in them that stop water from shooting out; they vent at slower rates.

It's usually best practice to vent the steam mains fast and the radiators slowly.

Bob

EBEBRATT-Ed

Look guys and @delta595

We need to know or post a picture of the tee feeding this radiator, If this tee is feeding straight up, the take off from the main is straight up and this is one pipe steam and the runout is not dripped to a wet return that radiator will never work, Condensate coming back down will kill the steam , cause hammering and you will shoot water out the vent.....especially with 1" pipe

AMservices

I had a service call last night on a system that's doing the same exact thing yours is @delta595. 
All the radiators work perfectly except 1, on the second floor. Last to even start heating and then when it does, the water hammer is REAL BAD. You can hear the waves of water crashing inside. 
It would only happen after the boiler started making pressure.  
I guarantee you... if you open the ceiling under that radiator you will find a pipe pitched the wrong way and it's trapping water. 
That radiator won't heat until enough pressure builds to push steam through the water seal. 
Try getting your hands on a thermal camera to see the piping through the wall.

markdelzell

main was raised to level because it was in the way?

dopey27177

Here a 1" has a very long run, the pipe is to small to carry the steam and let the water drain. Try this, in the basement at the base of the riser cut in a 1"T install a valve at the base and reduce the outlet to lets say a 3/8" valve to drain to a bucket, run the system and see if water will drain out and allow steam to flow to the radiator without spewing out of the vent valve. If that works you can pipe down to the wet return or install a water seal piped to the dry return.

1"pipe can only support 27 edr on a vertical rise. That is a straight run. What needs to be factored in is the amount of fittings that are the riser each fitting equals some amount of piping in addition to the rise. In your case some thing happened in course of years that affected the flow of steam and condensate.

Try what I propose. hope all will be cured with the experement.

Jake