HWH Solenoid Valve Rebuild

This is the valve that sits at the bottom of the first filter bowl. It is normally open and closes when the HWH pump turns on to level or refresh the slide room bladders. When the pump turns off, it opens to purge any filter “capture” which is why it can get filled with debris over time. The HWH part for the one I have is RAP6354 its for the TA-4101 compressor

The normally open leaves the filters and desiccant in a service “up-pressurized” mode so you can work on them without deflating the slide bladders or forgetting and getting a big surprise ;)

I decided to take my failed one apart and see what I found. With the unit apart I used some Biodegradable Rust Remover and a old toothbrush to clean all the mineral deposits off the parts, inlet and outlet.

The seal area is an electromagnet that pulls the plunger down on to the seat when 12V is present. The magnet is stronger than the spring on the plunger so it just pulls the assembly on to the seat.

Note that the plunger seal is also spring loaded, so you will want to get some cleaner down inside to ensure things move easily. The seat itself is a bit buried but you can use the eraser end of a pencil to get down and gently clean the seat. When completed I used some compressed air to dry the parts and clear out any loose particles. All back together and it seems to work fine.


Valve body disassembly.
Closeup of the electromagnet sealing side before cleaning.
Another view of the seat side and the plunger side. The plunger has a small rubber area that gets pulled in to the seat when 12V is applied.
You can see the debris that is on the valve seat. This prevented the the piston from properly sealing on the seat.
Parts all cleaned, ready to be assembled. I used a Biodegradable Rust Remover to get the parts clean. Followed by lots of clean water and some compressed air to dry it out.
Here the seat and plunger have been cleaned, look like new.
Note the plunger seal is spring loaded, be sure to get some cleaning solution in there to ensure it moves easily.