On Sun, 02 Jan 2005 12:50:27 GMT, (Gary R. Lloyd)
wrote:

On Sun, 02 Jan 2005 12:19:27 GMT, "Tom Ingle"
wrote:

You probably don't have enough pressure in your boiler. Check your pressure
gauge to see how much you have. Every pound of pressure is equal to 2.31
feet. So if your highest radiators are 30 feet above the boiler then you
would need at least 13 pounds of pressure at the boiler just to raise the
water that high.

While I agree with the above, I would add a couple points:

1. It is always a good idea to have a little extra pressure, so I
recommend measuring the height of the system and dividing by 2. For a
30 foot system, I recommend setting the minimum pressure at 15 psi.

2. When the boiler is heating, the water expands, increasing the
pressure. This extra pressure from expansion must be removed before
measuring and adjusting the pressure. This can be accomplished by
turning off the boiler and pump, then draining off water from the
boiler until cold fill water starts feeding into the system. Close the
boiler drain and wait. When the water stops feeding into the system,
this is your minimum pressure.


Why does the pressure increase and water expand if you have a properly
opreating expansion tank?

Adjust if needed, then turn everything back on and bleed the system
starting at the top.

Bleed the system starting at the top????????
Nope. Never

If you do it right, you will probably never have to bleed the system
again.

In theory, maybe, but not in the real world.
Maybe we are on 2 different "pages" here?
Fill me in.....
Bubba


_______________

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
Written by a veteran Service Technician

https://www.merchantamerica.com/tmethod/