Posted: Wed Nov 05, 2008 9:04pm

Hello again Tony, sorry to take up yet more of your time but,we intend to use our N/B as much as possible, at least 6 months of the year either at the marina or CC [we're both retired]. We want to put a Rayburn multi-fuel cooker on our 57ft N/B to give us hot water, heating & cooking, as we figure this will be far cheaper that doing it with diesel or gas, even if less convenient, we assume that wood will do during the summer and a mix of wood and coal for winter use. My first question is this, can I wire it up the same as one we had at home i.e. circulating pump & three way valve [Heating only, hot water only, both]. Hot water storage is with a twin coil chlorifier which had a mass of gate valves and criss crossing pipework which linked the Alde gas central heating boiler and the Squirel boiler [shared coil] and the heat from the engine [second coil]. The Alde was of the older type [Not balanced flue] and had a leak so I have now removed it and I’m about to tidy up the pipework. The pipework comes from the existing Squirrel with back boiler [brilliant, recommend it to anyone with a N/B regardless of size] which is halfway along the boat, [this will unfortunately have to go when the Rayburn goes in], to the chlorifier which is at the stern. The Rayburn will be further away, nearer the bow, but only by about six feet. There is a heat sensor mounted atop the output at the back of the squirrel, I assume this should be moved to a similar position on the Rayburn. Second question, the existing circulating pump is a bit noisy and mounted under the bed with the chorifier and I would like to change this for something quieter but not silent, so at least I’ll know it’s running, can you recommend one that will able to take the presumeably constant running, or is there an alternative option. Third question is, will fitting a room thermostat help and how or will be useless in an N/B, and last but no means least, can I fit a failsafe device so that if the circulating pump failed in some way the pressure accumulating in the boiler could be vented so as to avoid the boiler exploding or a pipe fracturing and showering someone with steam. I am thinking about a safety valve and whether it could be vented into the chimney via a custom made connection, seeing as how they would be close together, this would then take the steam out of the boat safely without danger to anyone standing on or near the boat. Hope these questions and ideas are not too daft, but as I am new to N/B’ing I feel asking the obvious rather than taking a risk is prudent and having read your answers to other peoples questions I keep finding myself saying ‘of course, I hadn’t thought of that’ and have also come to the conclusion that when it comes to wiring, heating & plumbing N/B’s ain’t the same as houses, not by a long chalk. Regards & thanks John

Posted: Wed Nov 05, 2008 10:19pm

Dear John, I am not really happy to advise on this because of the dangers from fire and carbon mon-oxide. I also think that unless the Rayburn is mounted on the centreline of the boat you will find you end up with a significant list. I will answer the questions that I can but first it is VITAL that any wood that is close to the cooker is suitably insulated and the a fireproof surface applied. At the least this should be an air gap of several inches, possibly filled with rock wool, and then ceramic tiles applied to something like Asbestolux board. You do not tell me about the size of pipework you have but as there is a pump we must assume it is not a gravity system that can operate simply by convection. This means a pump must be running all the time the stove is alight. The thermostat on the outlet pipe may be to turn the pump on in case you forget to (and thus prevent boiling etc)or to pulse the pump when the boiler outlet is hot. This may help heat distribution with low firing but I think the potential of failure requires careful consideration. I know of three 12v DC pumps, Bolin, Whale and one I do not know the name of from Legard Bridge Boat Builders. Join the Canal World Forum and do some searches or even just ask. There is a mine of useful information there. Unless you want to run the pump from an inverter you can not use a domestic pump. Using an inverter is not in any way efficient and is another thing to go wrong. The Alde vented via the header tank, so if you do away with the Alde you will need a header tank to feed the system. I think I would also run an expansion vent from (say) the top of the boiler outlet to just under the roof vented to the outside. If you assess a significant danger to people outside the boat vent it through the roof. I think if you vented anything into the chimney and it boiled you would most likely fill the boat with steam and noxious fumes. If the fire-door flew open you could also eject hot coals. However you pipe the Rayburn there must always be a sufficiently large heat sink on the system to prevent boiling. I suspect more than a towel rail will be required if you are trying to do a roast so the boat is likely to be horribly hot in high summer - think about it. Remember, join that web forum. Tony Brooks

Posted: Fri Nov 07, 2008 8:25am

One other thing, have you checked that you cab get it into the boat and then into place? I know I had a job with a normal Shoreline fridge because it would not fit between radiators and the bulkheads. I know you can always cut a hole in the roof but the cost would pay for a lot of gas or diesel. If the Marina has shorepower then consider having an immersion heater fitted to the calorifier, many already have the boss in place. You the have the stove for hot water and heat when away from the marina and a 19kg gas cylinder last us for months when we are only using it for cooking. I am sure you will have great problems removing enough ballast if you fit a Rayburn to one side of the boat, I will probably involve cutting several holes in the floor. Tony Brooks

Posted: Fri Nov 07, 2008 2:41pm

Thanks for that, yes we can get it in, the Rayburn is 23ins deep with the Towel rail and the dooway is 24ins wide. I intended to put a dozen bags of coal where the Rayburn is going to see how it affects the balance first. Is it possible to get an emersion fitted if there is no boss in place or will I have to change the chlorifier and if change is required would you recommend just an upgrade to one with emersion or is there a complete alternative. We're kind of experimenting with ideas at the moment and what seemed like a good idea at the time, thankfully you are showing don't always work in practice. I can only say, thanks again. Regards John

Posted: Fri Nov 07, 2008 6:08pm

If the calorifier does not have a boss then there is something called (I think) an Essex flange that can be fitted from the outside to accept an immersion. Although it should be fine I am a little concerned that if inexpertly fitted it might leak under our high pressures, however I know of boaters who have used one. I know of nothing that is anything like a calorifier or that will do the job of a calorifier. What I would say is that if you find that you do need to change it then get a stainless steel one so that you can fit one of the new Alde's later if that proves necessary. They can not be used with copper in the system. If you go down a mains immersion heater route remember mains can kill so perhaps it would be a good idea to employ a proper marine electrician who should also be able to discuss the options for protecting your hull from possible corrosion. If it helps I have fitted a stove (like your squirrel) and one of the upright Aldes and so far find they work well. If I set the Alde's room stat to about 15C it only comes on for a while in the night when the fire goes out. Tony Brooks

Posted: Fri Nov 07, 2008 9:14pm

This link may be of use to others re: what is an Essex flange. If you copy and paste this link remove any spaces that may appear in the address line. http://www.essexflanges.com/flanges.htm l#

Posted: Fri Nov 07, 2008 9:16pm

Sorry, got it a bit wrong, try this one. http://www.essexflanges.com/flanges. htm

Posted: Fri Nov 07, 2008 9:19pm

Must be old age, try this if you have not lost interest, but remember the remove the spaces. http://www.essexflanges.com/flanges.h tml#