Remove the wire guide And through the old pump away.
Taco 007 Pumps Have a direction of flow. Indicated by the arrow stamped on the back of the pump As a rule of thumb the pipe that goes into the boiler at the lower point is the return line and you want to pump the water from the house to the lower part of the boiler. In this case you want the arrow facing down Because the pump in on the return pipe of the boiler.
Another problem, The old pump had the power supply box on the right (with the arrow pointing down But the new one has it on the left I can not install it this way because there will be no way to get to the power box with out removing the pump. So I have to spin the motor.
There are 4 little bolts on the front of the pump remove all 4 then turn the head 180 % and pump the screws back make sure to tighten them down evenly.
Now it is facing the right way
Now put the wire guide on the new pump and tie the black wire to the yellow wire in the pump and the white or yellow wire to the white wire in the pump put the wire nuts back on Make sure they are tight and no wire strands are showing. put the cover back on and put the screw in.
Now put the rubber washers between the pump flanges make sure they do not get pinched and put the 4 nuts and bolts back and snug them up good but don't make them too tight and don't tighten one side more then the other. Now you have to fill the system with water and make sure you don't have any leaks. Then you will need to get the air out of the system
This is for gas fired boilers only I will be adding oil fired soon.
How do I know, If it is my pump that is bad? This is not a simple question. because allot of things could be the cause of a pump not running. and there can be many other reasons that you don't have heat. This may be mush more then you should try to do on your own. Maybe you should call a Pro.