Pete1987

Good point OldGoat, if the heater unit isn’t sufficient to heat the radiators and water I’m happy to heat the water by other means in exchange for red hot rads. I just wanted to check I’m not missing anything.

Yes Tony, if we’re out and about the main engine gives loads of hot water. I’m just aware we need a good, reliable hot tank of water to get three of us through the bathroom in the mornings.

Ex Brummie, sorry to sound a bit thick, can you explain? Do you mean that the rads will be deprived because the calorifier will gobble up all the heat?

Thank you all for your replies. Interesting suggestion about partially closing the gate valve, as when I tested it I opened the valve fully. I’d rather have hot radiators and warm water, as that can always be topped up by using the immersion heater. I was hoping to get set up so that the webasto can come on with the timer for a couple of hours from 4am so we can wake up to warm rads and hot water for showers. I’ll keep experimenting with the valve and give it a bit more time. If it’s not big enough to do everything I’ll let the webasto get just the radiators red hot then use the immersion for water.

Morning all, I'm new to canal boats and am fettling a 62x12 widebeam. I fired the heater up (Webasto 4.5kw) for the first time and it ran beautifully and warmed the 6 radiators up a treat, really warm. The water was cold, so after a bit of pipe tracing I located the gate valve to the calorifier and opened it. I could feel the hot water from the Webasto going into the tank so waited patiently. After about half an hour the radiators were much cooler, in fact just warm. I expected that the calorifier might rob a bit of heat from the rads but not that much. After another hour I had warm water and warm radiators, nothing hot enough to be of any use. Engine heats the water fine, although the coil in the calorifier is separate to the Webasto so probably not relevant. Is a 4.5kw heater enough for so many rads, calorifier and a big boat? When I shut the calorifier off the rads warmed up again to a proper temperature. I suspect the unit's not big enough to run everything? ambient temp was about 6 degrees on the day I tested it. Any ideas or anything I've missed? Thanks in advance, Pete