B2794 HVAC Heater Pump HAC-114 - no heat 2012 Leaf - Resolved!

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Dec 21, 2022
Hi all!

I have read several threads relating to failures of the two other water pumps in the ZE0 Leaf, but very little relating to the error above, so I thought i'd write it down here for the next person to find.

I had the above-mentioned error on my 2012 Leaf, showed up around a year ago, but I never got around to looking into it before now. The symptoms are that the heater first intermittently stopped working, which eventually became permanent. No heat ever fired up, and the error (B2794 HAC-114) never goes away. Most searches for these symptoms end up blaming the PTC heater or the fuse in the DC-DC junction box, but this issue has a much simpler solution.

It turns out there are three separate water pumps in the 2012 (go figure), where one is on the right-hand side of the engine bay, another is inside the left-hand side bumper (behind the left fog lamp), and the third one is located just underneath the 12V battery, but also underneath a metal shield that causes you to have to contort from below to get it out.

Steps to replace the heater pump:
  • Get the car on ramps
  • Remove the front undertray (make sure to curse whoever came up with the flimsiest screws and the flimsiest clips known to mankind)
  • Remove the 12V battery
  • Remove the battery tray (four 13mm bolts)
  • Move the water hoses you can see out of the way, and you'll just see the pump's input on the left, going into the mentioned metal bracket
  • Clamp the hose somewhere before this input, to avoid having to refill the entire coolant system
  • Snake your hand to the back of the metal bracket, and find the electrical connector to the pump, undo that (by swearing a lot at it)
  • Underneath the car, find the drain tap, and clamp the hose just after the tap
  • Undo the input found on the pump(step 5), move the hose out of the way
  • The pump should now be able to move about a bit, undo its bracket if needed to gain wiggle room.
  • With the pump out of its bracket (it's just press-fit into a rubber ring), you should be able to snake the whole thing down and get it hanging underneath the car, giving you the best angle to get the output hose off it, making sure it's still clamped...
  • With the pump off, do a bit of a victory dance.
  • Install the output hose onto the new pump, and snake it back into position, reinstalling the bracket if it needed to be removed.
  • Reinstall the input hose from above, and wiggle the electrical connection on.
  • Remove your clamps, and refill the coolant reservoirs in the general vicinity of where you're working.
  • Reinstall 12V battery, tray and holder
  • Start the car, listen for bubbles and refill reservoirs if necessary.
  • Enjoy having heat in your car again! (at least until the PTC inevitably dies...)

Lessons learned:
  • Someone was having a lot of fun dreaming up new places to put water pumps when this car was designed
  • The pumps all have different part numbers, but are apparently interchangeable, even with AZE0 and e-NV200 vehicles. The second-hand pump I sourced came from an e-NV200.
  • My local dealer wanted $1400 for the pump with part number 215813NF0A (which they insisted was NOT compatible with my vehicle), and $772 for the part number apparently delivered new with the ZE0.

Conclusion: The part number 215813NF0A will fit all pump locations on a ZE0, regardless of what Nissan will tell you. Other water pump numbers that look like the same pump most probably will also fit.

Good luck, and hopefully someone finds this useful!
Great info!

I heard an Ultima water pump for ~$70 (pre inflation) also fits. I'm sure someone can dig up the post.
Possibly, but the Ultima isn’t available in my market, so would be silly money from Nissan imported new :) the pump I got was from a wrecked 2018 e-nv200 with 29k km on the odo, so has many spins left in it :)
Long dead thread, but just wanted to say thanks, this tutorial helped fix my heater and its now working again.

The swearing part is definatly true.