On 02/11/16 13:06, Harry Bloomfield wrote:
I have long had an urge to buy or build a small panel with a row of
LED's which shows the status of my CH system and wonder if anyone has
done something similar? Idea is to be able to quickly diagnose any
problems, so I can fix them. I have long since forgotten the wiring plan
type.

I have - a condensing boiler, stored hot water, radiators on a wireless
room stat, LCD time clock, pump and three port valve. All the wiring and
the wireless stat receiver, terminate in the airing cupboard, where the
tank and its stat are located.

I'm thinking - LED's for pump running, call for space heating, call for
water heating, valve position indication, time clock says heating on,
time clock says water on.

I want to do something similar.

I was thinking either:

a) Cheap and quick: Load of GRID neons in a shop lightswitch style panel
with dymo labels. But not very pretty.

b) Get a nice panel made up online with a proper legend with a system
schematic. Then use LEDs - you can get mains LED panel indicators (with
inbuilt resistors and diodes) to make this less Heath Robinson.

I have seen places that will do laser cut various materials, so in
theory it should be possible to get a plate engraved with any diagram
you can draw in a simple SVG editor (I plan to use Inkscape - it's
free). It might even be possible to get all the holes laser cut in the
same operation which would be dead cool.



In either case, I'd also like to have override switches for each
subsection to aid in priming/bleeding - and also in the event any
controller fails.

My system will need some relays anyway to combine:


2 UFH demand signals -- UFH mixer pump

then:

UFH mixer pump -v
General call for heat from rads -- Boiler demand
Air space heating (conservatory) -^



Probably use more relays than technically necessary so I don't need to
assume every control device has volt-free contacts (though most do seem
to). Plus the control device for UFH don't have enough guts to power the
surge current a mixer pump pulls at startup.

It also makes it easy to add override switches.


I am not sure if it's best to put the override switches in the panel
itself or on a separate panel or grid box.

To be super complete, I'd like centre-off 3 position rockers or toggles
so each override can be:

Manual On
OFF
Automatic

with Automatic being the nominal setting.

Not terribly difficult to add in as all the logic is in one place, and
avoids lots of arguments with plumbers when the boiler needs a service:
"It's your CH controls guv"
"No, see here - this green light says "Boiler Demand On"