Hi All - I have been fitting Webasto Thermo Top C into boats for years and the following is advised:-
A pre pump filter is a must for the TTC and one can be mounted at any point on the system as the fuel pump is capable of sucking without any problems, the best is the aluminium bowel unit which can be purchased from any oil plumbing supplier or Toolstation on the web.
The exhaust system has to be lagged and the longest run must not exceed 1m in length - the silencer can be fitted but it will function without and the noise level is minimal without.
Bleed the fuel pump line on the suction prior to operating as this will stop the need for the glow pin having to work overtime as the initial operation sets the TTC into use as soon as the start switch is in the on position. If the fuel takes a long time to reach the burner then the TTC has to re started many times until it will fire up into full operation.
The fuel pick-up can be by a seperate fitted spill pipe or even taken from the suction side of the main fuel pump; however, consider a non return valve in the line to stop any fuel draw back whilst driving.
Webasto's normally need a burner clean at least yearly so I would suggest you need to site the unit for ease of removal and please consider fitting service valves on the water piping close to the TTC, this will again allow ease of removal without having air lock issues. Remember to bleed the water system to the pump by slacking off the top water pipe 'J' clip as one fills the system, otherwise the pump will air lock in the burner heat exchanger and shutdown of the unit will happen until water is bleed through the exchanger.
Any other questions - Please ask
Cheers
Bargeman
