I have a dehumidifier that runs but does not pull

There are a couple of things you can check for and they are; First of all, when you say the unit is running you may only be hearing the fan run. The compressor may possibly be not running(if it isn't running you will have no dehumidification as a dehumidifier is really nothing more than a small airconditioner.(cooling a coil for the moisture in the space to condense to). Second, The space may be to cool for the unit to run and dehumidify well, The space should at least be 65 degrees or warmer. Third, the system may have a leak and it is out of or low on refrigerant(freon). Depending on what you paid for the unit and if it has any remaining warranty(parts only-labor not covered) if the system is out of refrigerant or if the compressor is bad it probably isn't worth the cost to repair.