On Monday, March 1, 2021 at 2:40:23 PM UTC, Andrew wrote:

It feels hot but of course I haven't held onto the pipe for the full
time the boiler is running....
If your boiler is supplyng water at 80+ C then it wouldn't 'feel'
hot, it would be 'ouch, fkit' hot.
Can you check your 3way valve and make sure it is operating properly ?.

Yup - that's about the temperature (!) I'll see if I can get my IR thermometer on it later and find out roughly what 'ouch fkit hot' equates to....