Several Radiators Suddenly Started Panting

kram62

I have a single pipe steam boiler system. Boiler is gas installed in the 90s with an automatic low water level refill. Radiators working fine all season. No panting hissing or gurgling. Two days ago I heard the automatic refill kick on to refill the boiler. Confirmed refill in the sight glass. Ever since each time the system heats up every radiator in my hows begins to pant until the boiler stops heating, then the panting subsided. I tried blessing the system by turning up the heat until each radiator became hot and the panting stopped. But once the system cooled to normal temp and the thermostat attempts to maintain room temp the panting begins again. Note: radiators feel cool to the touch during normal heating. Boilers only on for a few minutes at a time every 10-15 minutes. Heats set to 68 and outside temperatures in the low 40s high 30s.

Any thoughts what why the sudden change and what I can do to correct? Thanks

Jamie Hall

Panting is almost always caused by condensate lying in a pipe somewhere. This may have been a latent problem, and only appeared when the boiler water level was raised, perhaps causing more wet steam to be carried over.

Check the pitch of all the pipes to ensure that they have adequate pitch and can drain properly.

Check the water level in the boiler -- should be somewhere in the middle third of the gauge glass.

Check the pressure -- no more than 1.5 psi.

Now. Having said all that -- it sounds from your description of timings that your thermostat may be set for forced air, not steam. Check and make sure that it is set for steam -- one or two cycles per hour.

ratio

Also, why did we feed water? It doesn't get used up, find out why it needed to add water.

kram62

Thanks! I’m not sure why the water fed but I’ll check into it. The thermostat is and old dial thermostat. There’s no external settings besides the temperature setting dial. How would I set for steam? I checked the sight glass and the water level is all the way to the top. Would this indicate that the boiler is over filled and causing the issue?

ratio

Possibly, maybe probably. Do you happen to know the level it ran out before the problems started? The mfgr should have a "normal water level" written down somewhere, look through the manuals (if they're around still—or download them) for it. If you're above that, lower the water level to where it's supposed to be at.

Big Ed_4

Plugged return with condensate lying in the main , maybe but no hammering ?

False water line ... Top petcock plugged

Another thought , if the BTU input decreased somehow ... With gas one would have to clock the meter and check gas pressures ...

Jamie Hall

If the sight glass is full to the top, who knows how much higher it really is. Drain the boiler down so that the water line is half way up the glass, if you can't find a water level mark on the boiler. Then keep an eye on it to see if you can figure out why it overfilled.

On the thermostat, there should be inside (you can pop to outer right cover off) a sliding lever thing which may, if you are lucky, be marked for longer and shorter runs. See what it is set to...

kram62

Thanks all! I took the sight glass down to halfway, emptied two 5 gallon containers, and that fixed the issue. Now just need to figure out why it filled.

Fred

Most likely reason is water is leaking past the valve on your Auto feeder.
Also possible the returns are partially clogged and the condensate is slow to return to the boiler. Water level drops, water feeder cycles, adding water, boiler shuts own and the slow water return finally gets back to the boiler causing the overfill.
Third reason might be an unstable boiler water li. Has any piping or other wok been done recently (or additives added) to the boiler or system? If so, that may have introduced oils into the water and the boiler needs a good skim.