Timer for Hydronic Heating

I have a question about the programming a solar, gas boosted in slab system with a 800 lstorage itre tank.

Is it better to:

A) set the temperature 'high' during the day and turn it down at sundown - to take advantage of the water being heated by the solar system amd warming the house and for the evening, or

B) run the system to heat in the morning, turn off during the day, and then kick in before we come home from work.

B was recommended by the installer, but I'm thinking that It would be using more gas, and not taking advantage of building the thermal mass in the slab during the day.

Your thoughts...?

We have recently installed hydronic in slab heating (this is our first winter) however we run it on a heat pump (also powered by solar system).

We were advised by the system supplier to leave our system running right through winter because it takes so long to heat the slab, any electricity saving you gain from turning it off is lost when you need to reheat the slab again. They suggested turning the thermostat down low during the day when no one is home.

The area of the house with the hydronic heating is very well insulated, has double glazed windows on the north and north west orientations.

We are finding we turn the thermostat up when we wake in the morning (the temp of the space hasn't dropped below 16 at the moment) for a couple of hours and then drop it back down when we leave for work.

I'm in NSW and today for example the house temp when I arrived home was 20 degrees and nice and warm.The warmth is the result of the few hours of heating in the morning, northern sun on the slab during the day and great insulation. At the moment the heating isn't on and the room temp has dropped to 18.5 degrees.

Very pleased with the system so far. Hope this helps.

Thanks for the reply. Can I ask how big your storage tank is?

The 'turn it down during the day' certainly matched the advice we were given at installation. This seems to be the advice for solar systems regardless of how it is boosted.

We are in Canberra - so the system will be on for many months to come! - and are embarking on our second winter.

We have it set so the room thermostat won't fall below 16 degrees overnight or during the day. We set it got 21 degrees in the morning and evening.

Today, for example, we had a top of 14 degrees after an overnight of -4. It's been gloriously sunny, so at 4pm the house has reached 22 degrees just from its solar 'gain' design.

Any more thoughts or experiences would be most welcomed.

Our storage tank is 315Lt. This tank supplies our hot water for our household of 5 people