Buffer tanks

[gravelrash]

New build with approx 3300w heat load at -5c, using loopcad UFH pipe layout it gives similar heat load so I think all calcs correct and it gives flow temp of 33c to maintain floor temp at 22c with 42litres of volume in system

I am not going with ASHP because 4m from gas main but obvious issues arise with Gas boilers only going as low as 40C.  I don't want a system boiler and large tank as only 2 in house so sticking with 

Combi and heating running through small Buffer tank- similar to how ASHP lads do it.  So looking for any input especially about availability of unvented buffer tanks between 40-60lts.(a tank with mid loop would be even better) 

[gravelrash]

bump

[J1mbo]

Wall-Mounted 40 Litre Decouple Module | Vaillant UK

[Marvin]

Another choice perhaps.. 

 

https://coolenergyshop.com/products/cool-energy-60l-stainless-buffer-tank-ce-b60

[JohnMo]

Have a slightly higher demand to yourself, and also running a combi, tried it without a buffer and the boiler just short cycles, so you are going the right way.

 

I have used an open vent thermal store, with the boiler heating the store via a coil and thermostatic switch set at around 40 degrees.  Using store as I want to dump excess summer solar PV into it as heat and then use as DHW in the summer.

 

If you can also run your cold water feed to the DHW through a coil in the buffer, this will preheat the cold water and improve DHW performance in the winter.