Where did my boiler pressure go?

haaljo

A couple of weeks ago I noticed no pressure reading on 30# gauge on same pigrtail as pressuretrol. Pigtail was plugged and replaced. Installed new brass.

Replaced 30# with 3# gauge and still no observed meter pressure. Gauge flutters between zero and the .8 ounce line.

Closed gate on all 12 radiators. Gauge indicated 1.6 ounces even after several hours of burner operation.

1) Don't seem to be losing water.

2) Gas meter clocked at 140K/hour.

3) All new vents with Hoffman 75 on main returns

4) All radiators get hot. Steam to all radiators after 40 minutes after burner had been shut off for 4 hours. Outside air temp. about 40F.

5) No family complaints (about heat :-))

Don't know when this started to happen. The gauge is seeing a little pressure as I opened the nipple from boiler and steam came out under some pressure. Last heating season, the pressuretrol would turn off burner at1.5# and turn on at .5#. Last summer, I installed all new vents and have skimmed the boiler several times. The boiler passages have been cleaned and the Economite gas conversion burner is providing a substantial yellow flame in the chamber. The boiler is a National Radiator Corp size 018-6. Possibly, the original (1938). One pipe steam system. As has been noted by several Pro's its amazing how an ounce or two of pressure can do the job. But it's driving me crazy why I can't get more than the ounce or two! Would appreciate comments and suggestions.

lutorm

Undersized?

Maybe your boiler is too small? 40 minutes to get steam to the radiators seems like a long time, so maybe it just doesn't have enough oomph to do it? You'd think that closing all the rad valves would do it, though, but maybe they are clogged and don't shut?

Jamie Hall

40 minutes

does sound a little long to get all the radiators hot -- but perhaps not, after being shut off for 4 hours.  On the other hand, I would have expected it to be quicker.



However, having said that, you have really answered a number of your own questions with tow statements: first, all the radiators get hot -- therefore balance and venting is probably pretty reasonable.  Second, no family complaints.



One comment: you do need a 30 pound gauge, in addition to the 3 pound gauge.  It's a code requirement.



I have to admit that I would think that the 3 pound gauge would show some pressure, particularly with all the valves closed.  But... perhaps not.  Perhaps what we are seeing is a system which happens to be sized so that the boiler capacity, while not undersized, is no bigger than it needs to be for the load -- in which case you probably won't see any pressure to speak of.



I would also point out that the extent of the improvements you have made on the system makes any comparison with before simply very interesting -- as an indication of how much improvement you have made!