1. In smaller size boilers, maintaining a small fire will produce less than 10,000 BTUs, but Keystoker’s efficient boilers trap and store maximum BTUs. Even a small maintenance fire will cause boiler temperature to rise above desired water temperature setting in the upper part of boiler. The loop will allow hotter water, stored in the top of boiler to flow naturally to lower part of the boiler. This will maintain a more even boiler temperature and reduce chance of overheating water.
2. Installing a loop will prevent boiler shock. When circulator runs cooler water from return, the line will not all dump into boiler. Some of the cooler return water will flow through loop and mix with heated water in supply line. This will allow circulator to run for a longer period which is especially important in large heating loads or for homes with radiators.
3. If timer is running too long, or if coal feed adjustment is set too high, water will be overheated. If water temperature reaches temperature setting of 4006B (recommended setting is 220), circulator will turn on to reduce boiler temperature. Cooler water from return line will be forced through loop to cool water quickly (approximately 10 to 15 seconds). This will lessen the likelihood of overheating the entire heating system.
