I need to buy an additional relay to use with my Shelly - which one?

Hardware
1

Morning all.

I am in the process of making my Y-Plan central heating and hot water “Smart” and have bought a Shelly relay:

https://www.shelly.com/products/shelly-2pm-gen4)

There is a slight issue, however, in that the Shelly has two SPST-NO relays in it.

This works perfectly for the central heating side as the heating is either on or off.

On a Y-Plan, however, things are slightly more complicated with the hot water side as I need two separate contacts, as this is needed to control the actuator. Ultimately, I need an additional mechanical SPDT NO relay, 230v 10A relay that can be controlled by one of the Shelly channels.

Can anyone advise which one to get?

There are some many variants out there.

2

I use a similar setup with a Shelly controlling a AZ2800 2C 240 relay, best to also use an RC snubber.
But the az2800 might be overkill for your case.

3

Can you use two Shelly modules?

4

Thanks guys - I did consider using two Shellys but the problem with a Y-Plan heating system

is that it needs a relay that connects one circuit when no signal is received but then switches to another circuit when the signal is sent. I couldn’t find a reliable way of using two Shellys for this, without using an external relay of a different kind.