[an error occurred while processing this directive]
Posted by Scott Ruffner on January 21, 2004 at 14:43:48:
I've got a National Gas Co (Johnstown, PA) boiler with baseboard radiators. The boiler has a "Penn" high temp shutoff. The house was built in 1949, and I believe it's the original boiler. I bought the house three years ago, and put central air in. The thermostat was replaced with a modern programmable.
It is a rental, and has some of the same tenants, but they are really pretty clueless: "the heat just seemed old, tired and weak like the house". It may have been that there was air in the system forever and ever. It may also be that the air was a recent problem, but the supply temp in the duty cycle has been low like this all along.
The system is hydronic (not steam), and was quite low on water (only some radiators worked). I've since filled and restarted the system, and now all the radiators get warm (although very slightly).
Previously the boiler supply temperature would get up to ~140F, but it now barely gets above 80F while the cycle is running. The call for heat activates both the circulating pump and the burner, and both shut off at the same time. I assume that the cycle is just too short for the boiler temp to really get up there. Previously none of the radiators in the room with the thermostat was getting warm.
The problem is, while the thermostat is located in the center of the house (1 story), the radiators in that part of the house are near the beginning of the loop. The radiators in several bedrooms are at the far ends of the loop, and the water is often barely warmer than 70F as it passes through those rooms. Basically, there isn't enough heat.
I don't know if things are really broken - from what I've read in this forum, it seems like the system is working OK, although I could change the circulating pump to run continuously, and just cycle the burner.
Is it possible to setup the system so that the boiler keeps the water a little hotter? The high limit is set at 170F. Should I just put aluminum foil over the radiator fins in the central (living) room where the thermostat is? If the low point of the water was more like 110F rather than 70F, it might help.
Thanks!
Scott