Correct installation of Willis Heaters

[joe90]

56 minutes ago, ZacP said:

would/could you use one of these as a backup for ASHP UFH?

Yes,

4 minutes ago, LA3222 said:

If you have your UFH running via a buffer tank then you can have an immersion in that tank

That’s what I have done, in case of ASHP /pump break down etc.

[ZacP]

Ooo no idea if I’m going to need a buffer tank or not. How does one determine this?!?

[Ferdinand]

Hmm. That's an idea.

 

If I were to update my ufh with a buffer tank, then I could put a heater in it and a diversion to use the solar currently fed back to the grid. Then I could feed that into the modulating Combi boiler to save some bills.

 

Hmmm.  

[PeterW]

44 minutes ago, ZacP said:

Ooo no idea if I’m going to need a buffer tank or not. How does one determine this?!?

heat source ..? And it’s preferable as you get less short cycles. 

[ZacP]

6 hours ago, PeterW said:

heat source ..? And it’s preferable as you get less short cycles. 

Undecided, but aiming for ASHP I think. Still required? Can it not switch between UFH and hot water if needed and can it also not be programmed to stay on for a minimum time?

[PeterW]

Yes as it will short cycle the closer it gets to target temperature. 
 
Depending on the unit they can sometimes have different flow temperatures for DHW and UFH,  but some have a single flow temperature which will either be too hot to directly do the UFH or too cold for DHW.