Boiler water reaches radiators with circulator pump off

[MichaelCreamer]

I recently had some preventative maintenance (cleaning mostly) done on my American Standard boiler (rather old, house was built in 1941).

The gentleman informed me, after the cleaning, that he had to repair a loose wire to "get it to fire" afterward. Since that "fix", the boiler now maintains the temperature (set on the boiler) all of the time-- even if the thermostat is in the off position. The problem, though, is that the hot water reaches all of my radiators even when the circulator pump is off. This resulted in a house temperature a few days ago of 81 degrees when the thermostate was set for only 68.

I'm OK with the boilder maintaining the temperature (even though it never did that before until the thermostate kicked it on) but the real problem is the water reaching the radiators constantly. Is that normal?

The company seems a bit baffled about this (but is planning to send the original guy) but I wanted to more fully understand how this is supposed to work myself.

The boiler is from American Radiator & Standard Sanitary Corp. I don't find a model number (where would that be) but the unit it probably close to 60 years old. There is a sticker on the side for the Honeywell pilot system (which I guess it was upgraded to at some point).

If anyone has any info. about my problem or the boiler that would be great!

THANKS!
Michael

[KField]

If the control was modified to prevent the boiler from maintaining temperature, the flow check may have been opened to allow free circulation so that all the hot water in the boiler could reach the living space and not sit in the boiler after a call for heat. If you can identify the flow check, see if the valve is in the open position. There are a few types of valve so I can't tell you how exactly to check it. If you are really unsure, get the name off the valve and I will see if it rings a bell.

Ken

[MichaelCreamer]

Thanks for your reply.

I don't see anything that looks like it might be a valve-- just the actual circulator pump inline in the pipe.

[KField]

The flow check doesn't really look like a valve and it would be in the supply not the return. It is usually at the top of the vertical supply pipe and is used as a 90 degree elbow. It may have a lever or wing nut looking cap on the top. I'm sure your service tech will know what to do.

Ken