SylvanLMP
quote:
Originally posted by john1330:
The second floor radiators are not filling with water to the vent valve. The one radiator that is only a foot off the floor will vent air then water. Then loses water over night. The hot water boiler in the basement is carring 8 psi.
WOW John today is YOUR lucky day you found ME.
Having 8 PSI will elevate your water to a height of 18.5 feet above your boiler NOT Good Enough I am so sorry to say
You see the manufacturers factory set the automatic feeder for 12-15 PSI.
Now instead of just boring you with an answer let me explain WHY the pressure is so important so you can also be an expert.
If your boiler was installed by a professional you will have a gauge that shows the following.
1- Temperature of the boiler water
2- A red area showing 30 PSI and hopefully a needle never moving.
This never moving needle was set by the installing plumber.
Now lets get to the nitty gritty
The non moving needle was the COLD FILL static pressure.
In another words the Licensed professional let this system fill with cold water and manually bled this system until all air was out.
Then this highly professional Licensed Master Plumber said to himself “HEY this is great BUT how can I make SURE I have a positive system pressure?”
So he/she decided to add an extra 4-5 pounds just for good measure and here is where the needle was set.
Now we also know water when heated in a closed place will expand (we call this phenomena PRESSURE TEMPERATURE RELATIONSHIP)
But we now have already set our pressure and here we go firing up our boiler and WOW the pressure continues to build up HOPEFULLY less then the set pressure of the relief valve (normally 30 PSI)
With this increase of temperature and the pressure we know we have a pressurized system with no air BUT now we have a problem WHERE to put this EXTRA Expansion and here come the expansion tank to the rescue (unless you have a really old atmospheric system open tank).
So what you need to do is increase (Cold feed) the pressure on the automatic feeder by slowly turning the screw down after loosening the lock nut.
Try to keep your operating pressure around 22-25 PSI
For your information you take the pressure and times it by 2.31 and this should give you a close idea how high the water will rise.
Have a great one and if you have any questions please feel free to E mail me.
