Let's start with the simple and go from there.
How are you plugging into a house outlet? What adapter are you using to accomplish this? Are you using an extension cord?
You said the house outlet has power. Have you checked to see if there is power "downstream" of the house outlet? If you are using an extension cord, have you verified there is power running all the way thru the extension cord? If not, then the cord may be bad (very common for this to happen).
If power, then once you plug an adapter into the extension cord (if applicable) or the outlet, is there power running thru the adapter? If not, then the adapter is bad.
If power, and you have a detachable RV cord to your trailer, have you verified there is power running thru the RV cord up to the point where it attaches to the RV? If not, then the problem is in the RV cord.
You can see how this is going, as you need to eliminate each link in the power chain to see where the problem lies.
Also do you have any kind of surge protector/electric management system connected as these devices can shut off incoming power if a problem is detected.
Does anything that runs off of 120 volt power work in the RV...like the television, microwave, inside outlets?
I'm asking this, to make sure there is actually no 120 volt power, and it's not just your converter or possibly a battery disconnect as to the reason your batteries are not recharging.
2011 Flagstaff 831 RLBSS
I used to be addicted to time travel, but that's all in the past now.