How to Fix Leaking Furnace Fuel Pumps

What You'll Need
New Fuel Pump
Hose Clamps
Locking Pliers
Bucket or Small Container
Work Light

One of the common problems with an oil fired furnace are the fuel pumps and their need for replacement. Many times the fuel pumps do not need to be replaced, but cleaned because of some debris that got into the fuel line from the tank. A leaking fuel pump is also a problem, but that necessitates the need to replace it. Here are some steps to take in fixing leaking furnace fuel pumps.

Step 1 - Turn off Furnace and Oil

Before doing any type of work to your oil fired furnace you will need to shut off the power to the furnace and the oil. This is done by using the power shut off switch. These switches are usually found in stairwells leading to the basement, along the side of the furnace, or some other easy access position.

Step 2 - Remove Access Panel

Locate the access panel of the furnace. This is generally located near the main motor of the furnace. Use a screwdriver to remove the screws that hold this panel onto the carcass of the furnace. You may need to use a 1/4 inch nut driver if the bolts to not have a slotted head. Once you remove the access panel, set it aside.

Step 3 - Remove Clamps From Hose into Pump

Removing fuel pumps can be a messy project. Before you loosen up the clamp on the fuel pump place a small container under it so it can catch all of the excess oil that is in the hose. Remove the clamp and pull the hose slowly away from the fuel pump. Let it drain into the container. A pair of locking pliers applied to the end of the hose will help to stop the leaking.

Step 4 - Remove Pump from Furnace

With the hose removed from one side of the pump, loosen the screws that hold it in place along the edge of the furnace. These are mostly simple machine screws that can be loosened with a screwdriver.

Step 5 - Remove Hose From Furnace Side

Repeating the same process as before, remove the hose from the furnace side of the fuel pump. Make sure you have another container to catch the excess oil. There will not be as much on this side as most of it is burned and not settling into the hose.

Step 6 - Replace Fuel Pump

To finish replacing fuel pumps you only need to reverse the order of removing it. Place the pump into position and connect the hose to it. Make sure you tighten the hose clamp enough so it will not leak. Attach the fuel pump to the side of the furnace in the position where the old one was previously. Remove the locking pliers from the infeed hose and slide it onto the nozzle for the fuel pump. Tighten the hose clamp onto the hose for a leak-proof seal.

Step 7 - Test Fuel Pump

Before you put the access panel back onto the furnace check it for any leaks in the hose. Turn on the furnace and let it run through a cycle. Check the hoses for any leaks. If you do not see any, replace the panel.