Furthest Radiator from the Boiler Problem?

David_53

Hi,

Thanks for your help in advance. Great website! So here is my problem. I have small 6 chamber commercial boiler...Weil Mclain model 80. 2 story building with 7 radiators and a three blowers. We changed the boiler several years ago and just used the oid original pipping around the boiler (now, I know this was not smart). The header and risers are about 6 inchs...so some big pipes.

So luckily all the radiators get hot and work but the one furthest from the boiler. I made sure it is open all the way. I bled the air out and changed the bleeder valve. I replaced the bleeder valve with one meant to release a lot of air. After I changed it, it worked fine for a week and then same problem. The valve at the bottom left of the radiator where the steam comes in is very hot and sometimes the first coil gets hot, but the radiator does not get hot. The heat does not travel across it. But then I bleed the air out and it seems to work for a few days and then the problem repeats itself. This is a one pipe system.

My gauge on the boiler reads that it cuts out at 4 PSI and cuts in at 2 PSI. This despite the fact that the pressure control is set so the cut in is .5 and the differential is 2....I know you add them together to get the cut out...so it should go off at 2.5 But the gauge does not reflect these settings. Maybe the gauge does not work...not sure. I know low PSI is the key...but I do have big pipes and this is not a home...so maybe a little extra PSI is ok.

Any advise? Thanks in advance!

Michael Wilson

I'm assuming this is a 1 pipe system, how is the pitch on the radiator? Check that with a 6-8" level all the way across. Maybe it needs to be pitched back toward the valve? Does the vent on the radiator make any noise at all during the cycle?



Lowering the pressure never hurts either ;-)
It sounds to me like your pressuretrol might be malfunctioning, or your gauge is bad... or both

David_53

Mike,

Thanks for your help. Yeah, this is one pipe system. The radiator is slightly pitched. How much should it be pitched? The odd thing is, this was never a problem until recently...so I tend to think the pitch is ok....since it has not changed.

When the heat is on there is a slight hiss and air coming out of the bleeder valve...and water trickling out a bit too. Is that normal? Should the radiator be full of water in a steam system? I mean I thought the steam gets to the radiator and condenses to water and then gravity takes it back down. But then I read somewhere that if a radiator is filled with water it won't heat?

Have a great weekend!
Dave

nicholas bonham-carter

water-logged radiator

try lowering your pressure to below 1.5 psi. under one psi is even better. you will probably need a good low-pressure gauge [gaugestore.com 0-3 psi] check the valve on the radiator, to see if it is not open all the way [they should never be closed]. you are right when the radiator is full of water, no heat!

check the main steam line vents for proper operation-one of them may have failed with your high pressure.--nbc

David_53

Hi,

Question...how do I know if the radiator is full of water? Do I have to take it off and take outside and put it on its side to drain it? If it is full of water than that just means it is not tilted enough and is not draining properly? The odd thing is this was never a problem up until this winter.

As for the main, I have never in 10 years since I have been here touched the main. However, all the other radiators on the same line that use the same main work..so could it be the main then? I was looking at it yesterday while the boiler was on and heard a slight hiss....so I guess that was air escaping....whether it is enough air leaving I don't know.

I will try lowering the PSI, but I think if I lower it so much the burner is going to cycle on and off continuously while the radiator is calling for heat.

THANKS for your help!
Dave

Jim Pompetti

Rad not working

Last problem like that was a plugged drip.The water could not get back

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David_53

Hi..thanks for your help. Sorry, but what is a plugged drip? Does that mean that the pipe where the steam comes up and to where the water drains is clogged? The pipe that connects to the radiator (of which I am referring) gets very hot...and the first coil on the radiator sometimes gets hot too. And like I said, after I bleed the trap it works for a couple days.

How do I fix a plugged drip?

Thanks for your help! Wish I could find a plumber near me who really knows what he is doing and about steam!
Dave

Michael Wilson

Short cycling

As for draining the radiator, you just have to shim it back toward the valve and the water will drain back down as it is supposed to... no need to disconnect the rad.


How big is this radiator? Over time they can develop a sag in middle and collect water..



If you lower the pressure and the boiler cuts on and of while you're calling for heat, you have an issue with your main venting.

David_53

Thanks! It cuts on and off because it reaches pressure and then shuts off and then comes back on cause the pressure goes down....still think it might be the main? Or are you saying the main is making it reach pressure too fast?

Steamhead (in transit)

Where

are you located?

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David_53

Westchester, NY

BAB

interesting

I read this website because I learn a lot, especially about steam systems. I am not a people person but I find some of the chat here very interesting. When you said ... "Wish I could find a plumber near me who really knows what he is doing and about steam!" .... I thought maybe you lived in Alaska, Uganda, or Mexico. When you later said you lived in "Westchester" I did a big "LOL".

I will be watching this thread with interest. Bromley

David_53

lol

Hi Bromley...lol...yeah, that is funny...no, not Uganda...New Rochelle. I'm a lawyer turned steam heat enthusiast...well, not really, just want to have heat! lol

Dave

Michael Wilson

> Thanks! It cuts on and off because it reaches

> pressure and then shuts off and then comes back

> on cause the pressure goes down....still think it

> might be the main? Or are you saying the main is

> making it reach pressure too fast?




Hey David,
If you lack main vents, the boiler will short cycle (cut in and cut out) while the system is still trying to expel the air contained within. Hunt around for vents on your steam mains and check if they are working.

If you do not find any, you might find plugs where they used to be.

Your problem however, sounds like the radiator is holding water and not allowing steam to get in...

I'd pitch the rad slightly and see what happens...
Also Check that the valve is 100% open