Heating relays

[hanky-pankysex]

Can anyone recommend a 240v relay, what I'm trying to do is use two pumps instead of pump and two motorised valves but when I send power to the boiler and one pump I don't want the other pump to run so was thinking if a relay

 

[truckster]

Why are you doing it this way?

A relay will probably be required, I've used 9 terminal relay bases before in similar situations and if the boiler requires an over run on the pump it can get complicated.

 

[hanky-pankysex]

Thanks, were using PAW pump stations so no motorised valves

 

[truckster]

Not familiar with the product but don't they produce/recommend a solution/wiring diagram etc? Perhaps someone else on here can help

 

[praxiscnc]

As Truckster; why are you doing it this way?

Normally the valve will give you the independent control wire needed, it will also ensure that gravity or flow from one pump doesn’t cause unwanted hot water circulation into the other heating circuit.

Domestic central heating pumps are not really pumps, they are ‘circulators’, if there is any unwanted water circulation it will go straight past the ‘pump’ so you could end up with areas getting hot when you don’t want them to. If a valve is closed, it’s closed!

If you need a relay there’s no end available from RS and others, if you are happy to fit into a suitable box / enclosure. Just ensure the relay can handle the load of the pump and that the coil is of suitable voltage.

Hope this helps.