Where is bleeder valve in baseboard heating?

Old 01-17-09, 05:44 PM
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Where is bleeder valve in baseboard heating?

I am having trouble getting hot water circulating to the top floor of a two zone baseboard heating system.

The lower floor baseboards get hot but I am having trouble getting water to flow upstairs.

I had to drain the system last summer to do repairs on the boiler and suspect that when I recharged the system, air got trapped in the second floor baseboards. I don't know that for certain. It's simply a suspicion.

I tried to find a bleeder valve thinking that there should be some way of venting trapped air from the highest point in the plumbing. I've not found one yet. Is it customary to have bleeder valves in baseboard systems?

Is there another way of solving this I've not considered?

Old 01-17-09, 05:56 PM
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Doubtful youll find bleeders on baseboard. HeatJockeys are known for their lack of forethought.

Your best bet is to pump water through that zone into a bucket until all bubbles are gone.

Good Luck.
Old 01-18-09, 07:25 AM
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Check to see that the system pressure is around 12 psi cold and a few more psi hot.

I have both cast-iron baseboards and the fin-tube type. All of them have bleeders on one end or the other, but a cover has to be removed to gain access.
Old 01-20-09, 11:13 PM
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bleeder valves

i doubt very much if you'll find a bleeder valve on any of the baseboards. they should be there but on 95% of them they are not. should be a drain valve to hook water hose to on return line near boiler above main circulator. shut circulator or zone valve off for that zone. attach water hose and run to outside, sink or large bucket. open valve with hose attached and open auto water feed on main water line to boiler. hold the lever on top straight up and let water run until you have good clear water with no air coming out end of hose. close water feed lever then shut off drain valve and disconnect hose. check water pressure on guage on front of boiler. should be 15 lbs. if not add water by lifting auto water feed lever for 3-4 seconds at a time. checking pressure each time. give it about 10 seconds between each add to allow guage to adjust. This should solve your problem. ( be sure you boiler is fairly cool when bleeding)
Old 01-21-09, 03:33 PM
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The math...

Check to see that the system pressure is around 12 psi cold and a few more psi hot.
I always like to add the math to the mix...

There needs to be enough pressure in the system to raise the water to the highest level in the system, when the system is COLD. The pressure will increase when it is heated.

12-15 PSI COLD is the norm... but on 3 story (or more) homes you will need more.

To determine the pressure needed, figure out the height from the lowest point (boiler in basement?) to the highest point in the system. Multiply that height by 0.433, and add 3-4 as 'headroom'.

For a 20 foot height as an example:

(20 X 0.433) + 3 = 11.66

12 PSI would be called for in this example.

The MINIMUM should always be at least 12 PSI, so even if you have a ranch home, don't go below that.

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