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Heating issue furnace not igniting

bigbeard
bigbeard Member Posts: 2
I have two heat zones for my furnace, 1st floor and 2nd floor.

When i turn heat on, on the 2nd floor, the air blows out cool - no heat. Also, the furnace is not igniting, but the blower is turning on.

The first floor has no issue with heating - it gets got and the furnace turns on. However, I do sometimes hear weird sounds and it struggles to ignite for 10 seconds or so. Also, if the first floor heat is on, then I get some heat coming out of the vents on the 2nd floor, if that is on too.

What is happening?

My system looks like this: https://ibb.co/T2HHRdc

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,400
    edited October 2022
    What is the water pressure on the boiler gauge"
    You could have air in the closed system. The circulator pump will not pump air. only water.

    From this picture, it appears that you have a boiler (not a furnace) that makes hot water. that hot water must go to a hot water radiator (hot water coil) inside the ductwork. When the thermostat calls for heat, the zone valve for that zone will open and turn on the burner and the pump to push the hot water to the Duct Radiator Coil. (Coil). When that Coil is filled with hot water the fan in the air handler will push cold air across the Coil. As the air passes the hot Coil the air gets warmer and goes into the ductwork to heat the rooms.

    If you followed that so far, then we can look at what your problem might be on the second floor.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,400
    edited October 2022
    I mentioned the Gauge on the boiler. In order to get the water to go high enough into the second floor air handler (if it is in the attic above the second floor) there must be a minimum of 15 PSI pressure (or about 35 ft. head) on the gauge. if the pressure is lower than that, the water will not get up the the air-handler. Let me know what the pressure is and can you take a picture of the air handler for the second floor? I'm looking for the Hot Water Coil and if there is a place to vent any air from the coil so, take picture from far enough back to see the ductwork on each end. Like this

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • bigbeard
    bigbeard Member Posts: 2
    Hello. Thank you for offering the help. The issue was the zone valve. I was able to press the switch manually. It seems it got stuck. I will most likely replace the valve.

    Strangely, the noise I mentioned is no longer being made. The pressure is just about 20 PSI.