Normally a recipe allows time for the TM to reach temperature Chris.
You could boil some water and see if that reaches temperature in the stated time.If it does,the recipe is naff and if it doesn't get your TM checked out by HO.
Fast and Easy cooking page 10
Water 1/2 litre 5mins100c/ speed 1
1 litre 8 mins/100c /speed 1
I hope this helps