I have an digihome 205. but what i dont like is when i switch it off to preserve power and box at night, i have to be there to switch it on to make sure the timed recording work. Many a times i forget and miss a show. I would like to use at plug timer but it is useless. So do all vestel boxes work like this?

All hard drive recorders, just like the video tape recorders before them, have to be plugged in on standby to work.
How do you expect a timer to work if its not getting power?
How do you expect the EPG - the list and times of programs to be recorded, to be updated if its not powered and tuned in to the tv signal?
You have to leave all recording equipment on standby.
A lot of this kit, like computers, also receives software updates from over the air and will cease to work properly if not left on in standby overnight.
Incidentally, the annual cost of leaving the box on standby is about the same as an electric kettle being boiled once per year to make a cup of tea, its negligible.

Yes but the Vestel box has a blank time after you switch it back on from the mains and therefore does not record with already timed recording. You need to bring it out of standby to get time back. My old digifusion work ok with being switched off, the time comes up on display and then records manual recording.

What's the exact model number of your Digihome and what is the software version number (can be found in the configuration settings screen)?

I'm not familar with a Digihome "205" and I wouldn't like to guess exactly which model you have, so it's hard to give you a proper answer on this. To partly answer your question though, no, not all Vestel boxes react this way. Most in fact will boot up fully when you plug them into the mains, and grab the current time in order to know when to wake up to record. Depending on the model, Vestel boxes will use under 1W in standby (low power mode) or 10W in regular standby. You can sometimes do more harm than good by frequently removing mains power from PVRs.

My mistake dtr207 (T810)

Ok - I no longer have a T810 box handy, so I can't test... Have you tried leaving the box powered on (not in standby) before removing the mains power? You may well be right about this model - IIRC, it displays --:-- on the clock rather than completely blank (sorry to be pedantic, but the newer models are completely blank in low power standby). The newer models, including T835, T7300 and T7650 do not suffer from the issue that you mention, and will happily record after mains power is restored without having to touch the box at all, although I would not recommend that - low power standby mode instead at <1W is negligable.

As davebav50 says power usage will be pretty low if you leave it connected to the mains, even as your T810 uses 10W in standby mode. If my maths are correct, you're looking at around £15 per year in total with the box plugged in 24/7 assuming a 15p per unit/kWh charge from your supplier. These boxes were never designed to be unplugged overnight (software updates are checked at 3am daily).

I presume your box is running v5.7 software?

Yes it has V5.7