Help with piping layout

[chuck172]

I'm thinking about doing some revisions to my piping setup this spring. My current system doesn't let me feed any open zones and charge the storage at the same time. The boiler comes to high limit, and I get some idling where I don't need to.
In the Tarm PT1 drawing they show the Termovar diverting valve (G).
Together with the zone valve(AV-1) and the circulator (C-1), will this arrangement divert some hot boiler water to storage and provide less boiler idling? Is the Termovar loading unit necessary, or can it be substituted with the Termovar tempering valve and a circulator?
see attached drawing

 

[Nofossil]

I can't really read the schematic, but if that's the standard Tarm layout then I believe the Termovar loading unit is essentially a mixing valve and circulator on one piece. Tarm likes the Termovar diverter valve to split flow. It will divert some water back to the loads if the return water is hot enough. In that case, some flow from the wood boiler circ goes to storage instead of supplying the load circulator.

This is an elegant solution. My only gripe is that with three zones, you have five circulators running to provide heat. If we assume 80W per circulator and that heat comes 50% from the boiler and 50% from storage, and that each zone runs 50% of the time, that results in a monthly power budget as follows:

Wood boiler circ: 360 hours - 29 kWh
Load circ: 630 hours - 50 kWh
Zone circs: 360 hours each - 86kWh

Total monthly power usage: 165 kWh. With a six month heating season and $0.12 per kWh, that's about $120 per year, or better than $2300 over the life of the system.

 

[chuck172]

In my case I use zone valves instead of circs., I'm curious about the Termovar diversion valve #K6440A3. If, like you say, it splits flow and will divert some water to storage, that might be what I need to do to prevent some boiler idling.