Little Giant Furnace Water Pump: Overhaul

Little Giant 554405 VCMA-15 non-submersible condensate pump

Awoke, we did, to a puddle at the foot of our basement stairs. Water. Perchance Little Weed had spilled a very large glass of water? Surely not. It turned out that our furnace water pump was no longer pumping. A repair was in order, and fast. Here is how I cleaned out the pump. It now works.

My furnace and air conditioner extracts water from the air. This excess water needs to go to a drain, but I have no drain in my furnace room. We therefore have an electrical water pump beside the furnace that pushes the excess water through plastic pvc piping, up and over to a nearby sink. This pumping process was not functioning, the water was overflowing the reservoir and soaking our carpeting.

As we have our furnace with Enbridge I made the call. It turns out that we had paid for a yearly maintenance call, but did not include service or parts. The service is farmed out to Enercare, which charges $129 + HST just to send a tech out to the house. As the water pump was external to the furnace, and the furnace was working just fine, all I wanted was someone to look at my water pump. He could not tell me how much for a new water pump, nor did he know much about furnaces. No thanks, Enercare, I do not want a repair plan that costs an extra $10/month.

I decided to look at it myself. How hard could it be, just a water pump? It turned out to be very simple and just like my aquarium pumps. You have a motor that turns an impeller, which is an underwater fan blade. The impeller forces water through the output tube. That is it.

Little Giant 554405 VCMA-15 non-submersible condensate pump

Little Giant 554405 VCMA-15 non-submersible condensate pump

The Little Giant Pump
My water pump is a Little Giant 554405 VCMA-15 non-submersible condensate pump, brochure, user manual. The warranty was for one year, long past. A new Little Giant pump costs $41CAD, so not expensive. A new one way valve costs only $10CAD, also not expensive.

Your product is guaranteed to be in perfect condition when it leaves our Factory. It is warranted against defective materials
and workmanship for a period of 12 months from date of purchase by the user.

Supposedly the VCMA-15ULS model will pump 65gph and a 15′ rise. The VCMA-20ULS will pump 80gph and 20′ rise.

Disassembly
Disassembly is quite easy. One Philips screw on the top and the cover comes off from the black base. Two more screws on the furnace and the base is free. The base was was overflowing, hence the flood. The base had brown calcium and lime stains. The submerged pump was slick with oil on the plastic and was discoloured. It was obvious that the pump was run when the furnace was new and the oil collected on the pump.

Little Giant 554405 VCMA-15 non-submersible condensate pump. Cover removed

Little Giant 554405 VCMA-15 non-submersible condensate pump, removed from black base. From the left: output tube, pump intake and impeller (large round part) , electrical switch, (rectangular) and pump on-off float (round with arm)

Thankfully this pump seems to be well made and has lasted since Aug 2010, or 7.5 years. Pumps like these operate thanklessly in the background, until they fail. I cannot say any bad words about this pump. Here is how to clean it.

Once the cover is off, there are two through bolts as well as 4 Philips screws. The nuts are 8mm, and needed a small wrench. The motor and submersible part comes away from the white plastic base. Pull off the fan blade. There is no bolt holding it on, only friction. Use a wrench to remove the output valve. This has a one-way check valve built in, so don’t go digging a sharp object right through the output valve. Remove the two bolts and the submersible part and spindle will separate from the motor. The impeller is in the bottom of the submersible part and does not come out. With the output valve away from you, using a needle nose pliers, remove the black (left) connector, blue (right) connector and the green (ground) wire, held down with one of the bolts.

Little Giant 554405 VCMA-15 non-submersible condensate pump. Motor with black (left) and blue (right) wires connected. Green (ground) still attached to one bolt.

Little Giant 554405 VCMA-15 non-submersible condensate pump. Motor with black (left) and blue (right) wires removed. Green (ground) still attached to one bolt.

Little Giant 554405 VCMA-15 non-submersible condensate pump, removed from black base. Output tube, pump intake and impeller (large round part). You can see the impeller shaft through the intake windows.

Little Giant 554405 VCMA-15 non-submersible condensate pump, removed from black base. Output tube, pump intake and impeller (large round part). You can see the impeller shaft through the intake windows.

The impeller and the submersible part was covered in old grease from the furnace. I used dishwashing liquid to submerge this part and scrubbed it well with an old toothbrush. With effort it came out clean.

Little Giant 554405 VCMA-15 non-submersible condensate pump. Motor from the output tube side, one way check valve removed

Little Giant 554405 VCMA-15 non-submersible condensate pump. Motor from the output tube side, one way check valve removed

It turns out that the black output valve was completely clogged. I let it soak in some CLR for a while, and carefully prodded it to dislodge whatever crud was in there. With effort I could blow air from the threaded end out, but not blow any air from the barbed end in. This is normal operation. For safety I might replace the output check valve. The part number is 154715.

Operation
The pump has a floating arm. When the arm gets too high the pump starts. When the water goes back down the pump stops.

The two extra wires are for an alarm. These wires are normally closed. There is a float that cuts the continuity when the water gets too high. I do not use these, but might have helped prevent the flood.

Little Giant 554405 VCMA-15 non-submersible condensate pump, alarm float (rectangular)

Reinstallation
Reinstall the two bolts, with the green ground under one of them. Reinstall the black (left) and blue (right) wire connectors. Reinstall the black output check valve tube. Reinsert your input water tubes into the top cover. Reattach the output pipe to the output tube. Plug in the power cable. Done.

Quality Review
Overall the Little Giant is well made and serviceable. Parts came apart easily, though the impeller was inaccessible for cleaning. I did soak it in soapy water. All bolts and screws came apart and went back together easily. I appreciate good engineering.

Interesting video: Clean a Little Giant Condensate Pump, 2

Parts:
Complete pump $47.91
check valve $6.29

I bought a new check valve from Amre Supply in Scarborough and it worked very well. The pump is strong and no longer overflows.