As above, thinking of having one installed to link up gas boiler, wood burning stove and possibly solar if we can get planning permission.

Looking for any pros or cons, things to watch out for etc.

Ta

I've got one from DPS. At the moment it is heated purely by 2 immersion heaters on economy 7 tarif, but it has a coil in the bottom for solar thermal (when I get around to it) and also tappings for a wood burner back boiler and regular boiler (if I or any future owner of the house wants to connect them). I've got a woodburner downstairs but at the moment it's just used for space heating and I probably won't be getting a back boiler version as it takes me enough time to get wood sorted already. The main issue with it is that it's not that brilliantly insulated, but it's a couple of years old now and I think the later DPS ones are better. Other brands are available.

With respect to getting hot water out, the heat exchanger produces very hot water at full mains pressure no problem, so no need for power showers and baths fill up pretty quick.

Their is masses of information on them on this forum, the website also sells several different sizes etc.

http://www.navitron.org.uk/forum/

Cheers Ben

Just installing a Jaspi GTV 700.

Linked to a Jaspi Biotriplex combined log and wood pellet boiler which has its own 200L tank inside. Controlers maintain energy levels between two tanks. Water directly pumped through UFH and radiators. Domestic hot water heated by two indirect coils (Mains pressure, potable DHW!). Solar coil to be connected later this year.

Cant link to pics as behind firewall. Will try tonight poss.

System not even comissioned yet (later this week, early next hopefully) so cant provide and feedback. Flue for boiler installed last week, so ready to go!

Will post when I have more info.

Is there any point linking one to a gas boiler?

Solar yes. – If you can do it then go for it. I haven't got a special thermal store, but a big 210L solar tank and solar thermal since April. I have not used any gas at all for hot water since I got it in.

I dont see much point linking one to a modern condensing gas boiler as they work so efficiently on their own that the losses associated with cycling arent significant enough to warrant a large thermal store buffer to iron it out.

However, for linking mulitple energy sources of which the gas boiler was the "call for" one, then I think it would work OK.

Here we go.
Ive not got photos of it plumbed in at the moment, but here it is on the way into the building.

Get the biggest one you possibly can and insulate the insulation and ll the pipe work too.
I'd do it here if I had the space

Thanks for the replies so far guys.

Boiler is a 12 year old baxi floor mounted job, it has loads of life left in it so I don't see the point in swapping it out if I can reduce it's usage and work load.

What make and size of thermal store is that Stoner? Did you get someone in to design the system or is it something you've spec'd yourself?

Sorry Wharfedale, been busy and offline.

That's a Jaspi GTV 700
http://www.jaspi.co.uk/GTV.html

It has, obviously, a 700L capacity. It comes with three indirect coils. The lower Im using for solar thermal the mid for DHW pre-heat and then the top one for DHW heat.

There are a number of ports off the tank. Two of which Im using for the underfloor heating flow an return.

The upstairs radiators are fed from the tank in the boiler (Woodviking Bio Triplex http://bbenergy.co.uk/pelletmasterandbiotriplex.pdf ) (c.200L) directly rather than the GTV, BUT there's a magic box and two pumps that moves hot water between the GTV and the boiler on demand. The boiler only gets called for heat when both tanks require it.

I did the heat calcs for the house, the boiler and tank set up was specified by BBEnergy http://www.bbenergy.co.uk/ a local guy – this is a pet offshoot business from his architects business. The UFH and rads layout etc was specified by me.

Installation of just the boiler/Tank was done by a plumber who understands the differences with such a system compared with more vernacular setups.

The 5m Class 1 twin wall flue was installed by a local Heatas guy.

Cost of Boiler, tank, controls, installation and commissioning is about £11k inc VAT

Flue was about £1,300 (No VAT)

I get my VAT back.

It will be eligable for an RHI at around 9p/KWh of deemed efficient consumption but the calculation for that hasnt been confirmed yet. I reckon that could be about 50p – £1 a day.

Once I connect up a solar thermal I imagine that for that proportion of heat energy deemed to have been produced by the solar will be paid at 18p/KWh replacing part of the 9p/KWh from the boiler.

You wont get any RHIs just for putting the accumulator in, but you would get something if you added an approved heating source.

Hi Stoner, Looks like an impressive system. Just about to fit a Woodviking. How are you getting on with your biotriplex? Any problems? Would really appreciate any feedback.