Vailaint Cylinder connections not 28mm? Is this ok?

Hi Forum,

Noticed the Vailaint Unistor range of cylinders for heatpumps, aren’t 28mm connections, like most other ‘heat pump cylinders’… is this an issue?

My newbie thinking is… since the cylinder heating circuit is seperated at the diverter valve which can run full 28mm index circuit to radiators, so the DHW circuit narrowing down at the cylinder to 22mm or lower isn’t bad, since it’s a sufficiently small enough run to not cause flow issues, as long as the coil in the cylinder is large enough to exchange the heat.

if that’s the case…does that mean I can use any unvented indirect cylinder with sufficient coil surface area to dissipate the output of my heat pump, even if it’s a 22mm connection???