- Make sure that the thermostat is set higher than the actual room temperature. If the system has central air, or the system is zoned, make certain that the selector switch is on heat. If the thermostat is programmable, fresh batteries might be needed. Hot water must circulate through the pipes and coil before heat can be produced, so allow time for this to take place.
- Make sure that the emergency switch(usually a red switchplate at the top of the basement stairs or at the side of the boiler),is on. There might be a switch on the air handler to check. An oil burner will have a red button on the protecto relay mounted on the burner. Press it only once. If it does not fire and continue to run, call for service. Resetting the button repeatedly can create an explosive condition.
- If the system has central air, move the fan switch on the thermostat from "auto" to "on". If the blower runs, it proves power at the air handler. If warm air flows out of the registers, the aquastat could be out of adjustment or the time delay is malfunctioning. If the blower does not run and there is power to the air handler, a control has burned out or the blower motor needs checking. Do not put fingers or hands in the blower. Aside from sharp edges, it could start up unexpectedly and cause a serious injury.
- Many air handlers have a safety switch that shuts off power if the door is removed. Check that the door is correctly installed.