Rayburn hot water tank

[wattreesmassive]

We had a Rayburn for 10 years at the old house and it was so brilliant we would like to install one in the new place.The old house was 2 storeys and the new one will be single storey,my question is,does the hot water tank {direct feed} have to be a set hight from the Rayburn? As there were no pumps in our last system,the Rayburn heated the hot water only with a small rad for a heat sink or the water would practically boil in the tank,I assume it was gravity fed,and the water tank was on the upper floor,so how high must we place the hot water cylinder from the Rayburn in a single storey building? Or prehaps it doesnt matter? Ive tried to find out online but the only systems I can find are indirect feed with central heating and we dont need all that,we like the K.i.s.s principle so we can fit and fix it ourselves!

[Zech]

Believe it or not, it's possible to get gravity feed with the tank on the same level as the heat source. I didn't believe it but our plumber insisted it would work, and he's right! Our system runs central heating and hot water off the wood burning stove (indirect), but the heat-source-to-hot-water-in-tank part should be the same. The trick is to have a vertical loop with the Rayburn on one side and the tank on the other. The pipe should go up from the Rayburn, then along through the roof space and down into the tank, then the return pipe should go from the bottom of the tank, along under the floor and back up to the Rayburn. It's the up-flowing pipe that's the important bit. That's what drives the flow of water round the loop.

The only issue we have with this is that when there's hot water in the tank and the stove's cold, it runs backwards, i.e. the stove becomes a heat sink. It's a minor irritation compared with having to put the fire out if there's a power cut!

Our system is non-pressurized, with a header/expansion tank above the hot water tank, and there's a heat sink rad coming off the hot water tank as well.

[woodi]

Yep, we too live in a single storey cottage, and the heating system had to be simple because I put it in myself. It is the height of the header tank feeding the hot water cylinder that determines your hot water pressure, which won't be incredible but definitely sufficient. As long as you ensure that the flow and return pipes to the boiler in the Rayburn don't have any dips where air can be trapped, and that you keep bends to a minimum, it should all work fine.
We just have a 15mm pipe off this main hot return from the boiler that goes around the radiators. On the return side of the radiator circuit, is a circulation pump (does the rads only, the rest relies on hot water rising to circulate). We have something called an injector Tee where the rad return re-joins the main hot pipe to stop it interfering with the main hot water flow.
So the tank always has hot water in it if the power goes off, and we only have a pump for the C/H. If the water gets too hot, flicking on the C/h takes the edge off it. I know that lots of these systems use a rad as a heatsink in case of over heating, but we've never had a problem. Also make sure that the header / expansion tank you use for the boiler circuit is metal (and the ballcock too), as if it really does boil, the plastic tanks don't fare so well, apparently.

[wattreesmassive]

Thank you both,I was imagining having to install some kine of "loft" in order to house the hot water tank! Now I know theres no need and that makes things much simpler! The water in the old system got so hot we had to turn the hot tap on and let water out before the tank blew! Is there any way to get rid of the "brown water" issue with an indirect feed tank? I did eventually get used to bathing in rust coloured water when the system overheated but itd be nice to have clear baths!