non working radiators in one pipe system

bigugh_4

I have seen the sand from the casting of the raditors cause blockage over time. You are correct in rinsing out the lines and rads. you are correct in making sure of the vents working. Is your piping insulated? Stop stand back and just plain look it over. Read the help topics and other stuff in the lable of the wall to the right.
Good luck. make sure the boiler is clear also, but do not place pressuer into it over just making sure. (30#'s at most)Same for rads, better to look than bust the cast iron!

ck quinn

branch on one pipe system not working

I have a one pipe system in our new old house. It has two main pipes. One main serves 6 small to mid size radiators. One branch serves two large radiators and one small. This second branch is not working- it is a short run as well. I have replaced all vents with new No.1 Vent-Rite vents. The boiler is 3 yeasr old and Well-MClain Gold 144,000 BTU and appears to be working fine, serviced today.

1- On the non working three radiators, the main gets very hot and two of the risers get hot but no heat to the radiators. The valves are working on two we know for sure. Cool air comes out of the new vents almost non stop when boiler is running. There is no main vent on this main, I will install tomorrow. Does not seem likley that this is cause for no heat to radiators though? The system has worked for years for previous owners without a main vent.

2- I want to clean the mains and risers. I had some luck with a high power vacuum today. Can I flush the lines with water as long as I disconnect prior to the boiler return? It seems that there is some sort of blockage ,but in all three branches? Is there a preferred cleaning method?

3- In the set of six that work, even with new vents they hiss air almost the entire time - is this right?

4- The boiler goes on and off in short intervals. It was serviced today-should it stay on until the thermostat reaches temp, or is it getting cut off due to the pressure setting which is at less than 1.

5- How do I know my pressure is right--my gauge goes from 0-30. I know that less than 1 in probably right but that does not even register on my gauge.

Steamhead (in transit)

Chris, your system

was designed to heat the house to 70 degrees on the coldest day of the year with no more than 2 pounds at the boiler. So you certainly do not need more than two pounds. I've seen these systems running with no more than 8 ounces.

The 30-pound gauge is a Code requirement. The gauge must be capable of reading twice the boiler's maximum working pressure, which is usually 15 pounds. But that doesn't take into account the fact that your system doesn't need anywhere near that much pressure.

Anthony Menafro

Sizing

Chris, Have you checked the boiler sizing. When this boiler turns off and then on, does it seem that the water line is low then rises again. I've seen new boilers short cycle as a result of improper sizing. Your water level will drop out prior to boiler shut off and will return allowing the boiler to run again. I'm suspect because the other rads get hot and these rads continue to blow air without ever getting ANY heat.Anthony