Dog Peeing on His Own Bed and Elsewhere?

I have a five year old male Labchow mix (neutered) who has, over the last couple months, been repeatedly peeing on his bed and on towels that are by the back door, (used to wipe his feet when it rains). We thought this was a recent thing, but we had to throw out our large area rug because we found a bunch of pee stains which were making the room smell. This means he has been peeing on the carpet for longer than the past few months. But now, he has continuously, almost daily, been peeing on his bed and on rugs or carpets even though he is let out twice in the morning.

We pay someone to come to our house everyday at 1 to let him and our other dog outside, and he is let out multiple times at night when my parents get home from work. There have also been times where every day he was also pooping on the floor.

He is trained to go outside to use the bathroom since he was a puppy. We just don't know why he is being so problematic recently. In the past we have tried taking his water away at a certain time at night, taking his bed away, throwing the rug away, etc. Any ideas? Thank you!

By Sara