Narrowboat with an Eberspacher I need to replace. It is listed on the build documents as a D5W with no suffix. I believe this may be an SC as there is no timer/programmer fitted. I am going to the boat 2nd week of December and an engineer is booked to change the units on the 10th. Can you confirm the SC is the basic model operated by a simple on off swith please.

the more noticeable difference between a D5W , D5WSC and D5WS is whether the fuel dosing pump and/or the water coolant circulation pump are integrated into the heater, or whether they are externally mounted. The SC version is a popular solution for Narrowboat, but by no means the only variant utilised for such application. Yes, they can be operated by a simple on/off switch if desired, perhaps more popularly operated via an Eberspacher timer that will also include fault error diagnostics etc. The most certain solution  to ensure you have the exact same model to replace your existing heater would be to check the heater data plate, or perhaps email a photo to sales@butlertechnik.com

Thank you