steam radiator vents

Brad White_203

In general, shutting off radiators is about the same thing and effect as reducing EDR. If you have an under-sized boiler, this is a stop-gap technique, assuming that the rooms do not need heat and will not freeze of course.

Now, as far as shutting down the radiator on the controlled (thermostat-containing) space? Just the opposite.

If you were using thermostatic radiator valves for example, the manufacturers advise to have them either not have these thermostatic valves or to lock them fully open such that it represents the core heating need.

It seems counter-intuitive, but it does make sense when you think about it, especially in that all radiators are supposed to come to temperature at the same time.

Gorton, among others, recommends using a smaller/slower vent for such rooms, consistent with this principle.

It may also indicate that your thermostat could be better located.

Raj

steam radiator vents

I have oil fired steam radiator heating. Recently had near boiler piping corrected, but since that has been done Im finding it difficult to warm the radiators furthest from boiler (second floor.) they all warm up well upon initially cranking up the temp. setting on the thermostat, but on subsequent boiler runs, only the downstairs radiators get warm, while the boiler cuts off before the upstairs rad. have a chance to warm. The thermostat is on first floor in room w/ 2 rad. which I think could part of the problem. Any thoughts?

2)Any opinions on Vari-Valve Air vents?, as these are the vents I have. The above problem is occurring even with the first floor rad. set to slowest setting and upstairs to fastest setting. Is it true they can only be adjusted once a day?

Brad White_203

Just venting here

I agree that venting is the likely source of your issues but may not be the only one.

Might I suggest that you check your main vents? Not letting the radiator vents do all of the venting is the idea. Also, might you check your thermostat for location and, if applicable, is there an anticipator that perhaps is shutting down your boiler too soon?

What I do not know, is the boiler shutting down on pressure first or temperature first? If pressure, suspect vents. If temperature, suspect the thermostat.

I had never heard that Vari-Valves could only be adjusted once per day, but then, leaving them alone is often a good policy for a lot of "adjustable" things.

I like Vari-Valves but you really do need dry steam; I find that they tend to spit sometimes. They will out-vent a Gorton D by half though, when fully open.

Raj

thanks for the input.

I had the main vents changed with the correction of the near boiler piping. Interesting to note that my system worked better before this piping correction, but it was running on high pressures.

I have my heating guy coming back next week to take a look. Will he be able to tell me whether the boiler is turning off on pressure or on temp?

I am suspicious that the problem may well be the thermostat location.

Why is it that some radiators still heat up even if the vari-valve is set to closed (all the vents are a week old.)? Should I be shutting down unwanted radiators at the horizontal run-out with the knob?

Brad White_202

Hi Raj

That is a bit odd but from here, hard to tell specifically. One can only prod and guess.

You yourself can tell if the boiler goes off on P or T. Just watch when the burner shuts off and how fast it got to the pressure (assuming you have a good gauge). If the space temperature is still below setpoint, there is the answer. If the system holds pressure for a while, that might satisfy the thermostat while doing nothing for the remote radiators. Just a thought.

A Vari-Valve is not an absolute close-off vent. In fact, until they see steam, I do not think that they positively shut off; no vent does that I know of, adjustable or not.

You might consider a thermostatic radiator vent valve (Macon OPSK's are one). That will give you a positive shut-off even if the vent passes some air.

Raj

Thanks for the input.

Do you think closing down unwanted radiators, for example one of the two in the room w/ the thermostat will help in reducing the heat in that room, so that the boiler runs long enough to warm the remote radiators upstairs before it cuts out at the set thermostat temp?

Thanks again.

Raj