No heat on third floor - seperate zone

Eric_17

Old victorian house built in late 1800's, boiler heat with single zone for first & second floors works; third floor has baseboard radiators on seperate zone with bleed valves. We can get air out of the bleed valves but no water and thus, no heat! Get pressure built up (air moves when valve is opened to bleed) when we repeatedly turn thermostat on and off for short periods - 15 seconds. Any suggestions to get the water up to the third floor. This is a two-pipe system from what I can tell.

[Deleted User]

Pressure

That could be caused by a couple of things. If you have no water getting to the third floor you may not have enough pressure in the boiler. You need 1 psi of water in the system to lift 2.31 feet. If you are going up roughly 30 feet the pressure in your bioler should be at least 15 pounds.
Have you bled the system? Sometimes at a high point you can get a lot of air. Try purging the system on the return side of the boiler if you have a proper purge set-up.
You may also have a flow valve that is closed. Is the pipe hot on the outlet side of the flow valve for that zone?

jackchips_2

Sure sounds

like a lack of pressure, Eric.Some of those old Victorians have very high ceilings and you may need up to 20 psi to get the water up there.

This can be especially true if your circulator is on the return which would cause a drop in pressure to the system.

Pumping away would be a great book for you and a good investment. Check out Books and More.

Good luck