vibration and rattle in baseboard radiator

garyrf

I hope someone can help me with this problem.

I live in a high rise apartment (buit in the 1960's) and have 2 sets of hot water baseboard radiators in my unit (living room and bedroom).
I generally keep the bedroom turned off at the shut off valve except during the coldest days of winter.

When the building started the heating a couple of weeks ago we got the normal "gurgling" and initial vibration as the system heated up, but these noises have continued and periodically become noisy enough to be quite annoying (there was some work done on the system last year-don't know if this is related).
I will be contacting the superintendents to look into this, but I have found from previous encounters that I get the best results if I can provide some direction as what needs to be fixed.
Am I correct in assuming that this is trapped air in the pipes?
If so, will bleeding the pipes from the valve in my unit fix the problem or does this have to be done centrally (and which should be tried first)?
If they need to bleed the pipes in the unit should the water be shut off for that section with the shut off valve or be left on in preperation for the work? What is the actual procedure for doing this?

Gary

HVACDave

Ussually you will have some air that needs to be removed from the system each fall as you have stated. In a high rise this can be a little more complicated, as the pressures in the system needs to be maintained at a higher level to push the water in the system to the higher floors.

It normally requires bleeding at each rad if the system has been opened up throughout the summer for repair. This may mean that each suite may need the rads bled, depending on how many suites are on each zone(depending on how high the complex is). If your suite is the highest floor of the zone, most of the air will accumulate at your rads.

Some larger systems have automatic air vents that are placed into the main lines to automaticaly remove air from the high points in the system. These can fail and may need replacement.

It is also common to loose pressure over the summer and need to increase system pressure for full flow to the upper floor rads. Making up for this pressure drop is generally accomplished by a pressure reducing valve, and backflow preventer from the city line pressure. It is possible that this is not working, or shut off.

I would start by asking them to bleed the rads in your suite and go from there, as you may need further information about the layout of the system to make any further suggestions. You may also want to see if other tenants are having the same amount of noise you are and determine if the problem is "in general" or only specific to your suite.

garyrf

Thank you very much for the information.
I will contact the building and take things from there.
This should be interesting as I suspect the bleed valves on these radiator units have not been touched since the building was built.

Regards

garyrf