Radiator vent holding water???

dinky8140

I have an old 1918 home with cast iron radiators. It has the one pipe system.

American Standard Boiler, 7 radiators, new pressure guage installed. Boiler never goes above 1/2 lb.

Some of the vents on the radiators are holding water in them, sometime a few drops and sometimes about a tea spoon. Is this normal? If not what could be causing this and what can be done to solve the problem?

Also I am in the habit of draining about 2 cups of water off the boiler every week, but only add water every 3 or 4 weeks. Do I have to drain a little water from this old boiler or not? I do get some dirty water when I do drain it.

Thanks for the help

nicholas bonham-carter

vents blowing water

the radiator vents should never blow out any water. you may have a problem with improper slope in one of the steam mains which holds water until the air/steam velocity rises to the point of carrying the water into the radiator and then into the vents, and finally into your room.

i would suspect that even though you only see .5 psi on your gauge, the pressure is going up higher. what you need is a good low-pressure gauge [gaugestore.com  0-36 oz.]. with an accurate gauge you will really know what the pressure is.

another part of the solution to this problem is correcting inadequate main venting otherwise the system will be diverting all the flow of air, and in your case water to the radiators, and into the room.  increasing the main vents will decrease the back-pressure closer to zero, and leave the riser air removal to the radiator vents.

the boiler supply piping also has a part to play in removing water from the steam, and yours may need some improvement. why not post some pictures on this thread so all can see what your above boiler piping looks like.

the good news is that when you correct problems with your steam system, you begin lowering your fuel consumption, and saving money, not to mention enjoying the comfort and silence, which these systems were known for, when first installed.--nbc

BobC

Water in vents

Are you draining the water through the LWCO, if so you just need to drain enough to keep that LWCO clean. drain it till the water is pretty clean. If the water is nice and clean you don't have to drain much, if it's dirty drain more.There are two types of single pipe steam. In a parallel flow system the main above the boiler is the high point, the main gently slopes down towards the return which feeds the condensed steam back to the bottom of the boiler. The steam and the condensate travel in the same direction. The main vent in this system is usually near the end of the main where the piping drops to form the return.A counterflow system has the mains low point above the boiler and it gently slopes up as the main goes along. The condensing steam travels back through that same main to return to the boiler. The main vent in this system is towards the end of the main.As NBC said those main vents have to be working and large enough to do the job. Get a level and check the main steam line to be sure it has the right slope. Also check the leader pipes that connect the radiators to the main to be sure they all slope back towards the main steam pipe.Please post some pictures of the boiler and the piping around it from different angles so we can see what you are dealing with. Do you have a single steam main or are there two? Also take some pictures of the steam main and the vents on it.Bob