The big fear with a back boiler is that the water will get too hot and so expand beyond the systems ability to cope. I don’t think just a towel rail will be sufficient.

The basic principles that I know of are that the first metre or so of piping should be copper rather than plastic, you need a pump to keep the water circulating and something to cope with the water expansion, like a tank with the top open to the atmosphere, in a similar way to domestic heating.

Regards

Pete

Hi Netty

My ‘2 pence’ on both your questions:

The power your laptop needs is tiny compared to, say, your fridge. It’s worth getting a 12v charger so you don’t need the inverter on. Even a modern inverter at idle will take apprx 30AH out of your batteries over a 24 hr period. That’s about the same as the fridge! There’s no such thing as a low power laptop, unless you go for expensive Solid State Drives (SSD). So unless you buy a monster gaming machine they all consume about the same power. The bigger the display the more the power. How you use it will make the biggest difference, ie use all the low power setting you can.

Regarding back boilers . . . please please be very careful. With great respect to you, the fact you are asking this question suggests you are not familiar with heating systems. The hot water must have somewhere to expand to. As Pete says, you need an expansion tank so that the water can expand as it gets (very) hot and then contract when it cools. If you don’t design this properly you’ll have a dangerous system when it’s hot and then air locks when it’s cold (as the system will suck in air as it cools if there is not enough water as it overflowed when hot.. or burst). Stoves are not like oil/gas boilers, they are very hard to control and your system must allow for that. I strongly suggest you get help, hot water under pressure is not funny.

I’m not trying to patronise you or anyone, but back boilers need careful design. I would hate you to have any kind of accident.

I think Paul means the laptop power supplies sold by such as Maplins. They plug into a cigar lighter type socket and come with a variety of plugs to match the socket ion your laptop.

For someone to do your back boiler I would ask your nearest boatyard or boat builder.

Regards
Pete

I did get a quote from a gas safe plumber who has marine experience. He was very clear on what needed doing as i sent him out a plan of my boat. Due to the cost im going to see how much gas I use this coming winter before i decide to proceed down the back boiler ave.

thanks