robbin Premium,MVM join:2000-09-21 Leander, TX
| Re: Rheem HVAC start up problem I had a similar problem with a Lennox furnace. This furnace was a normal efficiency (not condensing) furnace but it still had a fan assisted exhaust. There is a sensor in the ignition circuit that senses the amount of vacuum the fan is drawing. If it is not drawing enough it shuts the ignition cycle off. With mine the fan was producing barely enough vacuum for the ignition process to start but as the flames began they burned enough oxygen to trip the sensor and shut down the cycle. Troubleshooting this issue includes checking the sensitivity of the sensor and making sure that the flue stack is not partially obstructed (by a bird's nest for instance). In our case it was a design flaw and they had changed the specifications of the blower and sensor which required those items to be replaced. Obviously if your furnace doesn't have an exhaust blower then none of this would apply to your furnace. |