Heating system using a Gas Rayburn and Woodburner

[wallywobbles]

In my current house we use a woodburner with a back boiler and gas rayburn 480AG for the heating and hot water. It's not without issues because the woodburner gets very hot, and I can hear the water in the back tank of the woodburner boiling in a rather alarming way, but for some reason it does not heat the hot water in the tank, despite being meant to and the system was set up from the beginning (30yrs ago) to do this (originally using two fireplaces).

The house is warm enough, despite very mixed insulation, but hot water is a bit of a nightmare. We only have a 200l hot water tank, and 4 kids, so never enough, and I'm fed up of having cold baths.

We are moving to our forever home and taking the rayburn with us, and creating a totally new heating system. We want to continue using the rayburn and a woodburner with back boiler. We have our own wood supply.

The Rayburn does not have an integrated timer system so we just turn the heating element on when/if necessary, but mostly use the woodburner for heating. We don't heat at night. The heat from the evening fire and the heat of the Rayburn means our current house is rarely below 18°c in the day, even in the morning on a frosty day.

I am really hoping that someone can explain to me how the system should work - and what elements we need to make it work. Current heating engineer has tried to blind us with all the elements (I think) and is proposing something a lot more complicated that our current system.

I'm including plans - clearly not finalised in terms of room shapes, and working around the vast upstairs fireplace.