Thermal store heating system

[SSE]

Looking for some advice on rectifying someone’s heating system. The system was working but when it stopped working the sparkie who came to fix it messed about with loads of the wiring now it’s not working great. I’m going to look at it to try & get it going correctly tomorrow so just want to be prepared. From what I gather there’s an outside boiler that is heated when the HW is turned on at the programmer, when the boiler heats the water to temperature this in turn closes a stat which then pumps the HW? Does that sound about correct? There is also another pump & stat which I’m assuming is for the heating? There is also a wood burner which is to be wired so that when switches on will override boiler when boiler is off. I kind of get the general gist of it but not completely sure how to wire it so it works correctly. Any help would be much appreciated. The worst thing is I done one similar as this for the first time a couple of years back but can’t for the life of me remember how
I wired it.

 

[Shoei]

Thermal Store systems are a bit more complex than regular CH, it would be worth getting the MIs of their particular system to see how to connect the pump(s) valves(s) etc. Here's an example of one as a reminder of the main features.

 

[PEG]

Hi,i would be careful,you are not walking in to someone else's casserole of nonsense...
I have inspected a lot of these systems,where they were plain wrong,right from day one,and desperate owners,always always tell you it was fine,until...

The bit about "wiring up a wood burner" needs investigating,as they should function fine and safely,if all power is missing. Any safety
features,relying on pumping,stats,servo-valves,etc,is not...

Start from the beginning,and find the spec for the biggest lump,which will be the store or buffer,as it may turn out to be.
Work forwards from there,incorporating the other parts of the system,and their MI,to see if they are permissible,and functional.

What can happen,and i am not at all assuming it will with your good self,is that an initial prod,turns in to some work,then some more,as the problems surface,and then you are quick-sanded.

Some of these more elaborate systems,can become legendary in an area,with several unsuccessful engineers,swapping stories at the PlumbCenter counter...