help with 2 zone valves doing 2 pumps and one boiler

[WELLSIANA]

I am not too bad at heating in general but can someone guide me through this just to be sure on the lives side .
1 STAT which controls a central heating valve and pump plus fires a boiler
A cylander stat which controls a hot water valve and different pump plus fires the boiler.
where are each valves grey-brown-and orange connected
and as each zone on the programmer fires a different valve do you not get a feed back via the orange on the other valve or does this not matter

 

[mikhailfaradayski]

grey is generally perm live, orange is switched live.

no, you don't get feed back.

 

[WELLSIANA]

grey is generally perm live, orange is switched live.

no, you don't get feed back.

So u would go c/h on to stat common..stat calls to brown of valve..opens valve which makes orange and fires boiler and it wont harm back feed to other orange of other valve.
And same for h/w but via c/s
where if thats correct would you grab lives to greys from and what are the function of them to be permanant lives..why are they needed

 

[mikhailfaradayski]

Have you bothered to google any images of ch/dhw diagrams?
The answer to your questions are easy to find

 

[AndyPRK]

I would connect both oranges to live.
Connect both greys to the boiler and pump.

Then the brown for the hw valve goes to the hw stat

The brown for the ch valve goes to the ch stat


The other end of the stats go to the timer

 

[Lectrician]

By the sounds of it there are TWO pumps? In which case, you need to use relays to fire your pumps and boiler.

Easiest way would be to use two two pole relays, one controlled by the CH valve and one by the HW valve(or was it just stat?). then use one pole to fire the respective pump, and the other poles in parallel to fire the boiler. It could be done with less relays, but for the cost of them, this makes it easier t wire, and more straight forward to fault find etc.

 

[SimonH2]

Hmm, sound identical to this other recent question :
//www.diynot.com/forums/electrics/reverse-current.335006/

I'd use the switch in the zone valve to turn on the pump and a relay.
So on the zone valve, blue goes to neutral, brown goes to output of timer/stat/whatever. Connect orange to the live feed that supplies the controls (ie same feed as to the timer etc), grey to live of pump, and of course, neutral of pump to neutral of same supply.

Repeat for other circuit.

You now have two independent circuits where turning on the controls (timer on, stat calls for heat, etc) causes the zone valve to motor open, it's switch to close, and the pump to run and relay pull in.
Now connect the normally open contact on each relay across the boiler run terminals. Result is that boiler runs when either pump is running.

With some provisos, it can be done with just one relay. The electrics need to be all off the same supply (which they should be anyway for a domestic install), and the boiler must be happy with a live feed being shoved up it's run terminal (ie not a dry contact linking it's run terminal to another terminal on the boiler.
You need a changeover relay, with it's coil wired across one pump as described above. Connect the common to the boiler run, it's normally open (NO) contact to the same pump circuit as it's coil is powered from, and it's normally closed (NC) contact to the pump circuit on the other loop.
When the circuit with the relay coil connected turns on, the relay pulls in, it's NO contact connect the nor live pump circuit to the boiler and the boiler runs. When this circuit is off, the NC contact connects the boiler run control to the other circuit - and the boiler runs when the other pump is running.

 

[SimonH2]

Thinking a bit more, it can be done without a relay if you accept a couple of compromises :
1) The pump running while the valve is still closed.
2) The pump not running when zone of the one valves is opened manually.

Replace the microswitch in the valve motor head with a changeover switch. Wire pump and valve motor in parallel and to the output of the controls (this means the pump runs as soon as the control turn on, not after the valve has at least partially opened). Wire the changeover microswitch - common to boiler, NC to other circuit as previously described, NO to live of pump/valve motor.

Of course, the first time there's a problem, it will leave the lecky or plumber scratching his head - and when he fits a standard head (because the modified one is clearly faulty) the system will stop working properly.

 

[WELLSIANA]

Thinking a bit more, it can be done without a relay if you accept a couple of compromises :
1) The pump running while the valve is still closed.
2) The pump not running when zone of the one valves is opened manually.

Replace the microswitch in the valve motor head with a changeover switch. Wire pump and valve motor in parallel and to the output of the controls (this means the pump runs as soon as the control turn on, not after the valve has at least partially opened). Wire the changeover microswitch - common to boiler, NC to other circuit as previously described, NO to live of pump/valve motor.

Of course, the first time there's a problem, it will leave the lecky or plumber scratching his head - and when he fits a standard head (because the modified one is clearly faulty) the system will stop working properly.

well thank you all for your views and replies...my concern is when i first visited the job to price although 2 pumps where in the system the client said he was happy to just get a temp system working and hence i priced for a s or y plan but asked to meet with the plumber before i start as its the old client installed electrical works get me out of the ****e scene..when i met the plumber suddenly two more valves have appeared a circulation pump and a 3 channel programmer needed and altough i have not started the job its suddenly larger than i priced for but i thought if its still simple i will go ahead which now does not seem the case....a farmer may i add .

 

[SimonH2]

Sounds great - a moving target.
I'd suggest getting the client or his plumber to draw out the hydraulic circuit and clearly identify the way things are supposed to work. If there's multiple zone valves on one pump then wire that as an S plan - but add a relay (coil across the pump supply).

Then common up the relay contacts across the different loops to get a pump run control.

Draw a diagram for what you've done and leave it in the box with the relays - and keep a copy for your own records as you can be sure some **** will 'lose' any paperwork you leave.