The HR 25 Honeywell is much more reliable than the HR 30 after the German forums. I have no problem installing 4 (2 on M30 and 2 valves on Danfoss RA valves). adapters are provided. No problem. The HR25's menus are simple (but you have to call the documentation for the adjustment of certain parameters. Cote price, I've bought on Amazon.de (German Amazon, 4 postage for France) because they are 28 this site! much cheaper.