central heating burner wont ignite?????

Mine is accessed from outside.

Does anything happen when you turn it on?? Do you feel air blowing??

On call for heat the blower should come on. If it does not first check to make sure there is no on - off switch underneath the thermostat. If that is okay then check the 12 volt fuse for the furnace located on your converter.

Do you have to take the oven out to get at the burner and jets to clean or can this be done from the panel outside.?????

The serviceable parts of your furnace are all accessible by opening the outside panel. Before you tear into the burner assembly, make sure the other parts are operating correctly.

When the thermostat calls for heat, after a sort delay, the blower motor should start up. After the blower gets up to speed and the air flow closes a switch, the burner should ignite and begin heating the air. If these steps are not occurring in sequence, then let us know which step is failing. If absolutely nothing is happening when the thermostat calls for heat, check for an on/off switch on the thermostat, sometimes a small lever at the bottom, and check the fuse panel for a blown fuse.

You are not very forthcoming with the symptoms you are suffering and the make model of the furnace would be nice...
So in order to help you see if you can find your service manual at
http://bryantrv.com/docs.html

Dutch_12078 wrote:
The serviceable parts of your furnace are all accessible by opening the outside panel. Before you tear into the burner assembly, make sure the other parts are operating correctly.

When the thermostat calls for heat, after a sort delay, the blower motor should start up. After the blower gets up to speed and the air flow closes a switch, the burner should ignite and begin heating the air. If these steps are not occurring in sequence, then let us know which step is failing. If absolutely nothing is happening when the thermostat calls for heat, check for an on/off switch on the thermostat, sometimes a small lever at the bottom, and check the fuse panel for a blown fuse.

Hi dutch
I have turned the heat switch on,after a sort delay the blower motor starts blowing air in the living area and bedroom,but no burner ignite,when you turn it off you have a short delay before blower motor cuts off.?????????

When the T-Stat calls for heat the control board starts the blower (1)
The blower blows closing the sail switch (2)
The control board then opens the gas valve (3) and begins sparking (4.1)
Gas Flows (5) And ignitets (4.2)
The flame heats the flame sensor (5)
The flame sensor sends .480 volts to the control board (6)
which then detects the .480 and continues operation (*)
When the T-stat says "Enough already" (RV is now warm)
The control board shuts off the gas flow (*)
and then turns off the blower after a cool down (*)

*: At nearly every step the control board is involved. IF IT IS BAD, things will not work.. I recommend replacement boards from Dinosaur boards.. When Mine went out the Dino board was less than half the price and when opened the box the quality of construction and workmanship, and then design was very clear to my trained eyes.

1: No 12 volt to furnace, blower motor shot
2: Low 12 volt, air ducts clogged, blower "obstructed" bad sail switch
3: Bad solenoid, Clogged Gas Jet
4: .1: Bad ignition circuit (high voltage) on control board. .2: Points too wide (Very common it seems)
5: These do not often fail but they can
5: Bad connection, NOTE:
5 and * Bad wire.

* applies to all steps nby the way So does bad wire/connection.