Wiring diagram needed for a 3 pump central heating system

[Mal67]

Hi
I have been given the task of sorting out someone elses bodge job.

Big house with an oil boiler

2 CH zones and one HW
3 Zone valves (Drayton ZA6)
1 pump (that is not up to the job)
Horstmann programmer

The idea is to have one pump per zone which is what was originaly specified but I can't figure out the circuit. If i use the switch in the zone valves to trigger the pumps individually I can't trigger the boiler.

Help

thanks

 

[doitall]

Why not.

The zone valve orange can fire the boiler and start the pump, if you use the right relays

Relays

• doitall
• 15 May 2012
• 2

 

[Mal67]

Relays of course!

Thanks for the quick reply, much appreciated.

Any recomendations on relays, I can only find the Drayton RB-1 which is very expensive and out of stock!

Why not.

The zone valve orange can fire the boiler and start the pump, if you use the right relays

Relays

• doitall
• 15 May 2012
• 2

 

[BGEngineer]

Why don't you just use whatever is triggering the zone valve ie programmer/stats to also trigger/power the individual pumps. Then just let the zone valves trigger the boiler?

 

[matt1e]

rs probs your best bet

 

[matt1e]

Why don't you just use whatever is triggering the zone valve ie programmer/stats to also trigger/power the individual pumps. Then just let the zone valves trigger the boiler?

Because ideally you need the valve open before the pump starts

 

[BGEngineer]

Yeah ideally, but I don't think it will cause any harm in this situation. Besides the valve will have started to open when the pump starts.

 

[DP]

Yeah ideally, but I don't think it will cause any harm in this situation. Besides the valve will have started to open when the pump starts.

What do you think will happen if the valve motor goes belly up and valve does not open?

 

[BGEngineer]

As I said its not ideal but the worse could happen is maybe pump over till its fixed.

Anyhow these look ideal http://www.discountfiresupplies.co....50_60Hz-Coil)-in-Red-or-White-Single-Gang-Box

They are double pole but can be used as a single pole, good price and come ready to be wired.

 

[matt1e]

As I said its not ideal but the worse could happen is maybe pump over till its fixed.

Anyhow these look ideal http://www.discountfiresupplies.co....50_60Hz-Coil)-in-Red-or-White-Single-Gang-Box

They are double pole but can be used as a single pole, good price and come ready to be wired.

No the worst could happen is you could also destroy the pump!!
But saying that, there's not wrong with your link BG

 

[ir50]

Plug-in relay and holder - http://www.maplin.co.uk/round-base-10a-relays-2567

 

[gaswizzard]

Nothing wrong with triggering the circulators via the motor open of MV (brown) , been doing this for years with no issues.

I'm sure if one of the MV's went belly up the custard would get it sorted before any damage to circulator.

 

[rpevans]

Why not just replace the existing pump with a correctly sized one? Much simpler.
Rich