[Mounting accumulator tank]

The reason for a non return valve, is that as the water expandes (as its heated) if all the (hot) taps are closed, that expanding water can push the water back along the cold feed, causing an increase in presure, which could damage the pump if the PRV on the calorifyer is rated at a higher presure than the pump.

 

Its done out houses becuase of regs imposed by the waterbaord, who are very twiched about you pushing water from your house back into the water main, possably contaminating it. (i have never understood why they dont just fit a NRV on the supply to every house, not that they are so cheap and readly avable)

Daniel

 

For domestic water systems it's required where there is a direct connection to the main supply to prevent back-flow and possible contamination of the public supply in the event of a pressure failure in the supply. Your system, like mine is quite new and plumbed direct into the supply, without a header tank so requires a NRV. New outside taps plumbed into the rising main must have a NRV. Older domestic systems have a header tank where there is an air gap between the supply (ball valve) and the contents of the domestic system so back-flow cannot occur.

[Propulsion Motor Noise]

The question was prompted by my research into a possible new build utilising the Thames Electric Launch Co's Selectric system which can be installed alongside conventional diesel propulsion. Other options include a coccooned diesel. I hired an electric narrowboat from Castle narrowboats on the Mon and Brec last year and it was much quieter than the numerous diesel hire boats I've experienced over the last 20 years. It seemed to be based on fork-lift technology but it's one of only a handful in the country. I'd also guess it was in the region of ten years old. I've never been on a narrowboat with a coccooned diesel and so have no benchmark for comparison in this respect. That's why I asked.

[Propulsion Motor Noise]

Has anybody had the chance to compare noise levels produced by a cocooned, hospital silenced diesel vs a electric propulsion motor?

[Best Bicycle for use on the cut]

I've found that having a bicycle is very useful when cruising on the cut for lock wheeling and for shopping trips for the odd pint of milk when the nearest village is couple of miles away. The only problem is storage. A bike on the roof is a liability because it can get crushed or knocked off under bridges or in tunnels and is a menace when you need to walk along the roof and is always at risk of being stolen. To keep one anywhere else requires some sort of folding machine. I'm in the very early stages of designing a new boat and am considering devoting storage space to a bicycle. Who has experience of folding bikes on the cut? Can you recommend any particular manufacturer or even model? Are small wheels a problem on muddy uneven towpaths?

[Diesel electric narrowboat]

See Solomon Electric Wheel (Solomon Technologies). Their UK supplier is Enviroboat.