Kitchen company has recommended a Zip ES6 heater for under our sking in the new kitchen. Fitters are here now and kitchen well underway. Looking at Zip's web site it says the ES6 is for hand basins. There's a beefier one for not much more cash for washing up etc. Before I start moaning to the company, is there any way in which the model I have would be suitable? Dont want to sound off and then be told more lies.....