They don't die back Kidsgran. The leaves may take on a different colour in colder weather and change again in Spring. No need to fuss them too much. Just don't let them dry out, and give them a tug every so often to check if tight in the soil. If they feel loose, there may be vine weevil grubs nibbling at the root. You can even take them out, wash the root and repot in new soil. They will probably recover. They are tough and long lasting and easy to split.

Thanks Dorjac,
When can I split them , or should I wait until they are more established.

I would leave them to make more side shoots and bush out a bit. Later you can break off outer shoots and try and get a little bit of root with it too. You can lift the whole plant out of the pot to get a better view of which ones to choose. These plants are very forgiving and grow on quickly when the extracted shoot is potted up in fresh compost. Do that in the spring time perhaps.

Brilliant info thanks :)

I just checked one of my pots today, Stoplight. Found it loose in the pot, so I fished it out, and found that vine weevil grubs were feeding on the root. I must have missed it when I've watered with Armillotox diluted solution, which kills eggs and the maggots that munch the roots. The main enemy of Heuchera. I split it and now I have 5 Stoplights......I hope.