Hi, I just bought a Cape Cod and the second floor is freezing at night.
It seems the radiators don't get as hot as they do downstairs. It's hot
water heat, could this be an issue of the radiators needing to be bled?
I can't figure out how to do it. I turned the knobs pictured below and
nothing happened. Do these type of radiators get bled from the
Looks like you have an automatic air vent (The fat cylinder on top)
isolated by a manual shut off valve.
Open the manual shut off (turn the handle so it is inline with the
pipe). Unscrew the cap that looks like a tire valve cap. Press on
the little pin inside untill all the air flows out and you get some
water flowing out.
If you don't get any water, then you don't have enough water or static
pressure in the system, or you have a solid air lock; probably time to
call a pro.
If you get water, then screw the little cap on but leave it a turn or
two loose and leave the manual valve on. The automatic vent has a
float inside that should automatically bleed air but not leak water.
If water continues to leak out, the automatic vent has failed. You
can have it replaced, or you can turn off the manual valve and
remember to bleed them periodically by hand.
You may need to repeat this a few times over a few days to get all the
I believe it is already inline with the pipe from the picture correct?
So once the heat starts working properly I should turn to shut off to
the perpendicular position?
Unscrew the cap that looks like a tire valve cap. Press on
I just unscrewed the cap and a little air and some water flowed out for
about 2 seconds then stopped. There was no pin to press down just an
open end. Do I need to do this when the furnace is actually running? -
seems like it could be a little dangerous but I could use gloves to
keep from getting scalded.
Also do I need to do this to all the radiators in the house? The
downstairs ones seem to be working fine so I'd rather not mess with
them if I don't have to.
Yes, it's on in the picture. I'd leave it on unless you get water
leaking from the auto-vent.
The boiler doesn't need to be running; the static pressure should be
high enough to get water to all radiators without the circulator
running. But sometimes if it is really airlocked it helps to try it
when the circulator is running. It doesn't sound like you had much
air in there if it only came out for 2 seconds. You can try repeating
a few times over a day or two and see if you get hot water flowing.
Usually the air collects at the highest point, but it's not a bad idea
to bleed all the radiators once in a while. If they are working well
you can skip them if you like. But be sure to bleed all the radiators
on the upper level.
iT'S amazing how complicated this "automatic" stuff is. In college I
lived in what had been a 3 story private house, that now had 10
bedrooms and 3 baths, with radiators in every room (plus the living
room, dining room, kitchen and a couple in the basement.
We had no automatic, and all we had to do was bleed the radiators once
in the fall. And only the ones that weren't hot all the way to the
I suppose if there are air leaks in the pipes, it wouldn't last a
year, but the house was already proably 60 years old, built in 1905 or
so, and the apartment building I lived in next was built in the 30's
(it was 1968 then) and they didn't have any leaks.
Hot water is good, btw. Quieter than steam and slower temp changes
than hot air.
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