"Harry Bloomfield" wrote in message
. uk...
As I suspected, the actuator is sticking.

The original is a Danfoss HSA 3, which is sticking.

I have a brand new spare which looks in all respects identical, a
Sunvic SD 2701. It was bought as a spare head for our system, before it
was all replaced a couple of years ago.

Can anyone confirm whether this is compatible please?


Yes. Fully compatible. Check it out he

www.seered.co.uk