Blower won't stop running & it has no heat

It sounds like you either have a bad fan relay or bad t-stat that is keeping the blower on, but you will have to use a meter to find out why the heat will not come on. Get a meter and learn to use it, then check to see if you have 24 volts to gas valve when the t-stat is set to call for heat. Check to see if there is 24 volts between the Red (R on thermostat) and White (W on thermostat) when the t-stat is set to call for heat. If so, the t-stat is not closing the contacts to supply voltage to the gas valve. Check the power to the coil on the fan relay and if you have 24 volts after putting t-stat on "Auto" you have a shorted t-stat. If there is no voltage to fan relay and fan is still running you have a stuck relay and you need to replace it. On a fan relay you should be able to trace the wires to find the coil wires-they are usually two terminals on one end of the relay. Hope this helps. Note that when reading across a switch when you read no voltage the switch is closed and when you read voltage the switch is open. DrTom4444