My remote humax rt 531b doesnt always work ie trying to change channels even with new batteries

I would say that the infrared receiver in the TV is defective.

First thing to check is the batteries, then there is another trick to try: If this is an infrared remote control, you should be able to see the infrared light with any digital camera! Point it at a cell phone camera and press any button, on the camera you should see a violet light.

If you have changed your TV, you'll need to change the TV code in the Humax remote. See the TV code list at the back of the Humax User Guide.

You can specify the current time and Power On/Off time.
1. Press the MENU button.
2. Select Preferences using the / button and press the OK or button.
3. Select Time Setting using the / button and press the OK or button.
I think this is right

I don't think so. There really isn't anything to know other than installing the two AAA batteries. The PVR manual probably has the info you're looking for.

from "sceptical Glenn". I had the same problem & saw solutions so thought why not!!!.unplugged box, removed batteries,waited 10 mins.Held down "ON" button for a good minuet.Pressed all buttons from top left to right all the way down"like reading a book" even the ones under the slidey bit.Replaced batteries pressed buttons again in the same sequence,plugged the box back in pointed remote at box held "ON" button down for another minuet, then crossed my fingers.Pressed a button and it worked,"Wheay" success it worked it worked.Never again will anybody call me sceptical Glenn again.Thanks for the solution I am now a happy remote control using person once again, never having to leave my settee again only for a beer,or the loo or food,but that can also be rectified as I sit near the window...the pizza man can pass it through to me.

you problaly find one on ebay or google humax rt-531b and you may get it for free

New batteries.I had put new ones in but they were duff so I was misled about solution
Annie