Dont know if this helps-but that float in the gas pump was originally some type of plastic ball (or other tyoe of material), but we had similar issue, and after cutting open a gas pump we found that little ball had melted or warped from the heat of brazin all the line goin into gas pump. I cant remembr if that was on an rthc or rthd? hmmm. I'll have to ask.
The origional check valve was an issue. I remember attending a warantee meeting when the machine was still in development, and none of us liked the check valve design. I did change one which has the symptom you described. Just make sure the check is seating on the drain cycle by checking temperatures when in the fill & drain modes.
Another thought , you say the gas pump is working . How do you know ? just because the solenoids are alternating does mean its working ,the check valve could be blocked /stuck etc.
Did you hook up you laptop and run trendview to check "The Heartbeat" this is proof that the gas pump is working .
is this program the techviev program that u are talking about and also is this the only way to tell if the gas pump is working? how can one tell if the solenoids are leaking by., i hear that that can b a problem as well ., check valve can b an issue thought huh., can the gas pump be isolated to do the repairs?
I saw the service bulletin about the lines to the liquid level canister being sloped, there was also one that said something about if the insulation fails or falls off or whatever on the liquid pipe to the canister, "rapid and violent boiling" of the refrigerant caused by high ambients outdoors and inside mechanical rooms can throw off the float.
I pulled out an old float style liquid level sensor recently and upon looking at it, considering that the thing is surrounded by refrigerant and some oil and is not subjected to any force, I don't see how it could ever fail, or stick, or do anything other than what it was designed to do...
The RTWD has CHHP compressors, which are a different animal than the CHHC compressor you have on an RTHD.