On 12 Aug, 17:13, fred wrote:
In article
, Lee
Nowell writes



Thanks very much for the reply.

The trouble I have is that I am not confident enough to grow one from
scratch. *Whilst I think I understand the basics and logic, the wiring
bit (e.g. use of PLC/ relays) is a bit beyond my comfort zone...

Also, from what I can see, I have an additional problem to yours in
that I need to run the UFH with seperate pump and actuators in
addition to all the zones.

Maybe I could split the problem into 2
- UFH
- Non-UFH

and wire the demand from each in parallel to the boiler? *Not sure
whether that resolves the relay problem though - I'm not sure why I
need them at all to be honest...

You'd might be surprised at how simple the wiring can be.

Yes, you can separate that UF and conventional heating, that would be a
sensible place for a break but unless you use a truly synchronised
controller for the 3 conventional zones you are likely to run into short
cycling problems which may not be obvious but will stress the boiler
unnecessarily.

As I said, you could make this a lot easier with a bit of thermal
storage in the heating loop but it sounds like you have it already built
and aren't keen for that kind of change.

Relays can be a handy way to combine demands that need to be otherwise
isolated eg. in your case, where you have a pump for UFH and one for
conventional, using relays would let you combine those 2 demands to call
for heat at the boiler without switching on the pump on the other
circuit at the same time. Shout if you want a circuit.

Have you had a look at the uk.d-i-y heating wiki?http://wiki.diyfaq.org.uk/index.php?...tegory:Heating
--
fred
BBC3, ITV2/3/4, channels going to the DOGs- Hide quoted text -

- Show quoted text -

Thanks for the reply. A circuit diagram would be very useful -
thanks.

I had a further thought and was wondering if this would work????

Zone 1 – Under floor heating with 1 actuator – controlled by prog room
stat
-----------------------------------------------------------------------------------------------------------
Connect room stat demand to actuator, UFH motorised valve and UFH pump
in parallel

Zone 2 – Under floor heating with 5 actuators – controlled by prog
room stat
-------------------------------------------------------------------------------------------------------------
As for Zone 1 but wiring all 5 actuators in parallel with connection
to UFH pump in parallel with Zone 1


Timed secondary return pump
---------------------------------------------
Wired to the on/ off terminals on the timer

Remaining 5 zones – controlled by timers
------------------------------------------------------------
Connect the on/ off terminals for the zone to motorised valve


Connect the micro switches from all motorised valves together in
parallel and to the demand on the boilers

Finally, we have 2 boilers. Can they be wired together in parallel or
do we need any relay etc.?

Thanks again for all your help.

Lee.