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Hi, here is all the information that I could find on this subject: Gravity fed systems for heating with a backboiler - the Intro section says enough that you can get a rough idea of what you must do (Added on the 18/09/2015) - Key principles is enough to get you started - and in Design there is more information for geeks who like to understand it all, or for people who need to debug I am designing a simple system which does not include a calorifier, so I have not included any information on this subject in this Summary. If you would like to add it, let me know and I will let you modify the text. There are still some questions that have not been answered. I have copied all of them here, below. If you have a short and clear answer to any of these questions, please post it here and I will add it to this summary. I might start discussion threads for some of these questions, if it turns out that the answer is complex and needs further discussion, or if no-one answers the question in the next few days. Important questions: Slope: - Why is the return pipe often straight-ish? Is the slope on the top pipe more important than the slope on the return? If yes, why? Pipes: - do you anneal copper pipes yourself, or do you buy them annealed? - could I use plastic hose to connect both the top pipe and return pipe to the radiators? That would save a lot of copper pipe bending. What would be the drawback, apart from appearance? The hose would have to tolerate boiling water temperature, too... Header tank: - is it a good/bad idea to have the top of the header tank outside of the boat? Radiators: - how can I know whether a radiator has a suitable bore, or whether it will cause too much friction? Coolant: - can you use tap water, or should you use distilled water? Why? Fiiling ratio: - how much water / coolant do you put in your system? (read the relevant part of the document, for more info) Geek questions: Thermostat: - is a thermostat only useful if you have a pump, or also for gravity-fed systems? (to prevent the water from flowing below 30C, for example) And where would you put it? On the return, on the top pipe, or on both? Pump: Apparently a centrifugal central heating pump would allow water to circulate via gravity when it's not running. Is that true? How would you choose such a pump? (how much power, etc) Anti-freeze: - Why do you need to premix anti-freeze and water before? (what difference does it make?) - How much anti-freeze do you put, with water? 50%? But Anti-freeze does not flow as well as water, and does not transfer heat as well, so less anti-freeze might be better? Is 30% alright in the winter? Pipe size: - Why do people recommend a 22mm pipe to the header tank, instead of a 28mm pipe which would make it easier for hot water to escape? - Is it better to have 28 to 15mm adapters on the rads, or to have 15mm pipes Tee-ing to the rads? The second options enables to have a tighter bend, which causes friction, but enables the radiators to be higher. Misc: - SmileyPete said this in an old post, and I don't understand the word "lagged" in this context, any idea? Here is the text: "a good way of doing it is to have an adequately sized gravity 'heat dump' rad(s) near or next to the stove, then more distant rads and/or calorifier on a pumped circuit connected by 15mm pipes, ideally lagged. That way the gravity rads can be shut off and all the heat directed to the furthest rad." ------------ I wrote this by reading, organizing and summing up all of the relevant information discussions threads that are mentioned in the Index of common topics on this forum, plus a few other sources of information on internet.

Hi Everyone, Does anyone make back boilers to fit small stoves? Width would need to be less than 280mm. If not could I just use a zigzag of 28mm copper pipe inside the stove. I have access to a mag drill so cutting the holes should be relatively simple. I'm replacing my broken morso squirrel with back boiler with a slightly smaller 2nd hand cast iron stove and would like to fit a back boiler to it as I already have the pipe work and radiators. The squirrel boiler is just a little too large.

Hi all, I recently switched my boat around and removed a diesel stove and installed a conventional multi fuel stove, I honestly cant believe the difference!!! I intend to install a mini range in the cabin (a 2-3kw mini multi fuel), I have seen one which can have a backboiler fitted to it, I would like to connect this to the calorifier to heat up my water (as I already have existing pipe work and pump in line). The stove will be about 10-12foot in distance from the calorifier and will not heat any radiators en-route, my concern is that the water in the piping will wet too hot and start to vapourise as there will not be enough heat dispersing during the short travel time. Is this a warranted concern? My intent is to run the stove 30 mins to 1 hour per day in order to give me enough hot water for a shower and to do the dishes. Again, any help would be really appreciated! (stoves seem to be taking over my life at the moment) Thanks!!!!

We need a woodburner for our house out here in France, but french prices are ludicrous, so wonder who is the best supplier in the UK for a stove of up to 20 Kw, log burner only, with backboiler?

hey all, we have a constant kettling going on with our back boiler and have decided that with a 2 yr old on board we arent gonna mess around risking it going bang. i would like to remove the back boiler and re-plum the pipes back into its old circuit. does anyone have any advice on which replacement parts id need to buy to return the burner to its original condition? baffle, back plate? thanks in adnvanced all :D