I have a house with a 1956 Bryan A-14 copper tube hot water boiler. I
noticed that my gas usage was skyrocketing with 100's of cubic feet of
gas going out each week. I changed the old thermostat and saw that the
thermostat correctly turns the boiler on and off. I then watched the
hot water gauge controlled by the aquastat. It was originally set to
100 and I changed it to 140 and watched it burn.. It got up to temp at
140 and then correctly shutdown and occassionally refired. But then
after sometime it stopped firing and the temp in the water dropped down
Then when the house temp dropped it would refire and bring the water
temp up again and repeat.
I noticed that the aquastat is a L4006A and is obviously set as a high
limit cutoff. My book says that there is an automatic differential of
5 built in, non-adjustable. Shouldn't the boiler kick back on when the
water temp drops below 5 degrees of the set point? It was doing the
same thingy of me bob when the temp was set to 100, except it was
constantly cycling on and off and I could figure out why?