Altitude Gauge

FC

Can someone explain to me the function of an altitude gauge on a gas fire boiler (American Standard...pretty old). The gauge is a combination thermometer and altitude. I just don't know what the altitude reading indicates....sometimes it goes into the red danger zone ??

Mark Eatherton1

A.K.A....

Tridicator. It shows pressure of fill, static head (altitude) and temperature. The first two are essentialy the same. If yours is going into the red, it indicates a need for service. Your expansion tank may be water logged, and your pressure relief valve may need replaced. If you don't feel comfortable working with fire and water, contact a professional qualified to do the work for you. Try Find a Professional on this board.

ME

FC

Altitude Gauge

Thanks for the info. One follow up....how can I tell if the expansion tank is full ?

bob young

expansion tanks

conventional tank---drain it. be sure to break vacuum. x-trol bladder diaphram type shut auto feeder pres. red. valve to isolate. run system. if pressure climbs----replace x-trol tank---most probably ruptured.

FC

Altitude Gauge

Replaced tank this morning. Now pressure goes right up to the red (30 lbs), but goes no further. The old tank was
definitely full. It was from 1986. I guess it lasted long enough. Under $30 and some sweat did the trick (hopefully). Thanks for the help.

Mark Eatherton1

You still may have a problem....

generally speaking, the intial fill is based on 1/2 PSI per vertical foot of system elevation above the gauge, plus 5 PSI. You may need to readjust or replace the pressure reduction device.

Either that, or the new tank you put on is substantially undersized...

ME

bob young

i am waiting for our court notice's to be served. lol