[OpenTRV-dev] Sparmatic - does it fit a TRV4?

[Kevin Wood]

Well, a follow-up on this. The answer is yes!

I bought 4 heads, and they came with a variety of fittings including a
ring with a 30x1.5 thread on it. It screws onto the valve body and the
sparmatic just clips on top. Easy as that.

I had an issue in that 2 of the valves on which I fitted them started
leaking, though. Particularly irritating as I'd only a few weeks before
drained, cleaned and flushed the system due to a previous leaking valve
and subsequent ingestion of air had turned the water manky.

I suspect, since one had already failed, the valves were on their last
legs and disturbing them was the last straw (maybe cleaning the system out
didn't help either but it was necessary to preserve the boiler!). The
house is now 15 years old, after all.

Managed to seal the system up airtight and replace the 2 valves without
draining down my new dose of inhibitor and they've been working very
nicely since.

The LCD is obviously designed for the more continental practice of
mounting TRVs horizontally at the top of the radiator. It's both
upside-down and unreadable due to the viewing angle when mounted on a UK
radiator but the valve head is easy to pop off whenever access is needed.
When I replaced the valves, I should have tried mounting them
horizontally, actually, as that might have made the display more readable.

Programming 4 of them individually was a pain, and they do require manual
intervention when a room is used unexpectedly. In addition, since they
have no mechanism to call for heat from the boiler, rooms can be slow to
heat up if the system is already up to temperature and cycling on the room
thermostat. Despite that, they have achieved a much higher WAF than I
expected them to!

We do now have 3 rooms downstairs that are no longer heated in the morning
when they are never used and the bedroom is only heated in the morning, so
they are making savings, I'm sure.

Central management and occupancy detection would be the icing on the cake
for me, though.

Kevin