Anyone have any viewpoint on this unit? Installer was/is due to fit a vaillant, and has ordered one but due to backlogs at vaillant there is a chance it may not arrive in time. He’s trying to see if one of these could be available but obviously not guaranteed. Can’t find a huge amount on it as just launched in June apparently…
Looks like it’s a rebadged Vaillant Arotherm Pro, which would make sense, as Glowworm is a subsidiary of Vaillant.
Whether the controller is fully compatible with the ebus protocol and all the integrations which have been built around that, and whether that even matters to you, remains to be seen.
Advertised as a ‘no faff’ whatever that means.
Does it do cooling? Looks like from the manual and configured for it. So better than Vaillant which you have to buy other bits.
Manual is typical Vaillant.
Most heat pumps are as good as the installer or the installed system.
City a plumbing have them in their store.
I went Hiaer without knowing anything about them really.
Yes, I believe it’s identical to a Vaillant Arothem+, just rebadged
Vaillant only requires a resistor to enable cooling. Glow-worm will be the same since it’s the same unit. The glow-worm cooling resistor is listed in the brochure, part number: 001000974 https://www.glow-worm.co.uk/glow-worm/products-1/controls/glow-worm-independent-brochure-uk-final-010925-digital-hr-spreads-3061617.pdf
There’s a significant price difference! I guess it shows how much of a mark-up, Vaillant is making. Glow worm seems like a bargain
Just relooked at manual and although it says cooling all within the text, it says slot for cooling resistor also. Another cooling con
Few high-volume manufacturers sell cooling-enabled A2W ASHP in the UK, likely a hangover of legacy MCS stipulations precluding cooling support.
At least the barrier to enabling cooling on Vaillant/Glowworm products is relatively low (£6 resistor, 2 minutes to install). Others make it significantly more difficult, like Daikin: impossible without replacing the entire mainboard (£££ and voided warranty).
Haier, Maxa, Panasonic etc do it out the box
Same for Grant HP290 and all Samsung models, cooling is available out of the box.
It’s very straightforward to enable cooling on a Vaillant. I can understand why some manufacturers require jumping through some hoops, since without careful consideration to dew-point and condensation it’s possible to cause a lot of damage to a property e.g Grant will only allow cooling if the controller is set on fan-coils or UFH
Mitsubishis have a DIP switch to enable cooling.
This may be true if the WRC is used for cooling control, @glyn.hudson, but you need a second roomstat - and maybe some other minor bits - for cooling if a third party (remote) roomstat is used for heating control, if I understand Samsung Helpdesk correctly (see Reversing flow around the heating circuit when cooling - #2 by SarahH).
Yes, that’s true. But the same would apply to any heat pump if a third-party heating control stat is used
…so not quite “out of the box”, then… 
Does Vaillant give larger rewards to installers and trade discount than Glowworm?