Ok, you say you have the back off the machine and the link filter it on the top panel, now pull the lint filter out and remove the 2 screws under the lint filter, then go around back there will be 4 screws holding the lint filter tube in place, remove the screws and pull the lint filter housing out. once out at the base of the lint filter housing where it joins on to the blower housing see if there is a blockage, if there are debris clean the housing out then re install it and try the machine again on a 30 minute timed cycle.
If the flame improves you are all set, if the flame does not improve the valve is bad and will need to be replaced. There is no way to test the valve, But by process of elimination it will be your valve.
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