It is now several weeks since we received the boat back with its newly fitted Webasto Thermo Top C central heating, so I thought I would report on how we are getting along with it. Before I do, I would just like to congratulate Navigation Narrowboats, the sister company to Nantwich Marina Ltd., who fitted my new heating system to the highest standards. They have just had the first ever back-to-back win of the Lionel Munk Trophy for the best commercially built boat 2011 / 2012 at the IWA Festival with their boat Oakmere. Well done, read about it here...2011 IWA Festival Award Winners
We haven't had much weather that has been cold enough to fully test our new heating system yet, but we have used it over some of the more chilly weekends, if only to get the hang of it. First thing to note is that the system does not incorporate a room thermostat, and one isn't available as an optional extra from Webasto. The boiler measures the returning water temperature from the radiator circuit by means of a hydrostat built within it. This cycles the boiler according to the demand placed upon it, which makes it important to balance the radiator surface area available, excluding the calorifier, to the available output of the chosen boiler. The guys at Nantwich Marina did all this for me, and installed the Webasto Thermo Top C, which has a maximum rating output of 5.2KW. Webasto suggest that the boiler output is balanced as closely as possible to the radiator's dissipation of heat, so that problems don't occur with too frequent cycling.
The kit supplied includes a small electronic control unit, which, in our case is fitted to the bedroom bulkhead. This provides a manual on / off button as well as a 3 event timer. There is a multi-event 7 day timer available as an optional extra at approximately an additional £100. There are also several wireless remote control options, and an interface that allows control via mobile 'phone SMS text message.
The controller, as supplied, manipulates the boiler through a warm up cycle and a cool down cycle, which is a feature that helps stop the unit coking up through excess carbon deposit. During use the boiler then uses a variation of burner options to control output according to demand. Radiators should be balanced using the appropriate valve on each one, so that all reach a uniform temperature or as required by the user.
So far, in use, we have noticed it is much more efficient than our old Alde gas boiler, and the boat gets warm very quickly. The fuel use is rated at between 0.2 and 0.6 litres an hour, which equates to approximately £35 - £100 per week, if used on a fairly permanent basis, but I suspect we will use it in conjunction with our solid fuel stove, as it is probably intended, rather than the sole source of heat. This should also work better than the Alde, as it won't be fighting against the room thermostat in order to start operating. The unit also provides piping hot domestic water. So far, I am very impressed, even though it is a less sophisticated unit than other brands on the market, but also remembering it is also much cheaper.